Particle number size distributions and concentrations in transportation environments: a review

Ambient air ultrafine particles (UFP, particles with a diameter <100 nm) have gained significant attention in World Health Organization (WHO) air quality guidelines and European legislation. This review explores UFP concentrations and particle number size distributions (PNC-PNSD) in various transportation hotspots, including road traffic, airports, harbors, trains, and urban commuting modes (walking, cycling, bus, tram, and subway). The results highlight the lack of information on personal exposure at harbors and railway stations, inside airplanes and trains, and during various other commuting modes. The different lower particle size limits of the reviewed measurements complicate direct comparisons between them. Emphasizing the use of instruments with detection limits ≤10 nm, this review underscores the necessity of following standardized UFP measurement protocols. Road traffic sites are shown to exhibit the highest PNC within cities, with PNC and PNSD in commuting modes driven by the proximity to road traffic and weather conditions. In closed environments, such as cars, buses, and trams, increased external air infiltration for ventilation correlates with elevated PNC and a shift in PNSD toward smaller diameters. Airports exhibit particularly elevated PNCs near runways, raising potential concerns about occupational exposure. Recommendations from this study include maintaining a substantial distance between road traffic and other commuting modes, integrating air filtration into ventilation systems, implementing low-emission zones, and advocating for a general reduction in road traffic to minimize daily UFP exposure. Our findings provide important insights for policy assessments and underscore the need for additional research to address current knowledge gaps.

Association between commuting time and work-related low back pain with respect to sports and leisure activities in Korean workers

Long commuting times can induce work-related low back pain (LBP), which can be exacerbated by reduced sports and leisure activities. However, there is a lack of empirical research on commuting time and work-related LBP in Korea. In this study, we aimed to investigate the relationship between commuting time and work-related LBP as well as the effect of sports and leisure activities on Korean workers. We utilized data from the sixth Korean Working Conditions Survey to analyze the relationship between commuting time and work-related LBP using multivariable logistic regression. The total number of included workers was 28,202. Workers without sports and leisure activities, and long commuting times (40-59, 60-79, and ≥80 min) showed significantly higher odds ratios for work-related LBP (1.29 [95% Confidence intervals=1.12-1.49], 1.42 [1.22-1.65], and 1.96 [1.68-2.28], respectively). However, in workers with sports and leisure activities, the results were significant only for commuting times of 60-79 and ≥80 min (1.41 [1.13-1.75], 1.60 [1.28-1.99], respectively). Long commuting times were associated with work-related LBP, and engagement in sports and leisure activities was found to play a role in mitigating the impact among Korean wage workers.

Does cycle commuting reduce the risk of mental ill-health? An instrumental variable analysis using distance to nearest cycle path

BACKGROUND

Previous studies have linked cycling with improved mental wellbeing but these studies tend to use cross-sectional survey data that have small sample sizes and self-reported health measures, and are potentially susceptible to omitted-variable bias and reverse causation. We use an instrumental variable approach and an objective measure of mental ill-health taken from linked administrative data to ask: 'Does cycle commuting reduce the risk of mental ill-health?'

METHODS

Our study links data on commuting in Edinburgh and Glasgow from the Scottish population census with mental health prescriptions from the National Health Service Prescribing Information System records. We use road distance from home to nearest cycle path as an instrumental variable for cycle commuting.

RESULTS

In total, 378 253 people aged 16-74 years living and working in the City of Edinburgh and Glasgow City council areas at the 2011 census were included in our study; 1.85% of commuters in Glasgow and 4.8% of commuters in Edinburgh cycled to work. Amongst cyclists, 9% had a prescription for mental health compared with 14% amongst non-cyclists. Using a bivariate probit model, we estimate a mean average reduction in prescriptions for antidepressants and/or anxiolytics in the 5 years following the census of -15.1% (95% CI: -15.3% to -15.0%) amongst cycle commuters compared with those who use any other mode to commute.

CONCLUSIONS

This work suggests that cycle commuting is causally related to reduced mental ill-health and provides further evidence in support of the promotion of active travel to encourage commuters travelling shorter distances to shift to cycle commutes.

trips4health: a single-blinded randomised controlled trial incentivising adult public transport use for physical activity gain

BACKGROUND

Public transport users tend to accumulate more physical activity than non-users; however, whether physical activity is increased by financially incentivising public transport use is unknown. The trips4health study aimed to determine the impact of an incentive-based public transport intervention on physical activity.

METHODS

A single-blinded randomised control trial of a 16-week incentive-based intervention involved Australian adults who were infrequent bus users (≥ 18 years; used bus ≤ 2 times/week) split equally into intervention and control groups. The intervention group were sent weekly motivational text messages and awarded smartcard bus credit when targets were met. The intervention group and control group received physical activity guidelines. Accelerometer-measured steps/day (primary outcome), self-reported transport-related physical activity (walking and cycling for transport) and total physical activity (min/week and MET-min/week) outcomes were assessed at baseline and follow-up.

RESULTS

Due to the COVID pandemic, the trial was abandoned prior to target sample size achievement and completion of all assessments (N = 110). Steps/day declined in both groups, but by less in the intervention group [-557.9 steps (-7.9%) vs.-1018.3 steps/week (-13.8%)]. In the intervention group, transport-related physical activity increased [80.0 min/week (133.3%); 264.0 MET-min/week (133.3%)] while total physical activity levels saw little change [35.0 min/week (5.5%); 25.5 MET-min/week (1.0%)]. Control group transport-related physical activity decreased [-20.0 min/week (-27.6%); -41.3 MET-min/week (-17.3%)], but total physical activity increased [260.0 min/week (54.5%); 734.3 MET-min/week (37.4%)].

CONCLUSION

This study found evidence that financial incentive-based intervention to increase public transport use is effective in increasing transport-related physical activity These results warrant future examination of physical activity incentives programs in a fully powered study with longer-term follow-up.

TRIAL REGISTRATION

This trial was registered with the Australian and New Zealand Clinical Trials Registry August 14th, 2019: ACTRN12619001136190; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377914&isReview=true.

A prospective study of the impact of COVID-19-related restrictions on activities and mobility upon physical activity, travel behaviour and attitudes

Background and aims

Public health measures adopted to contain the spread of COVID-19 included restrictions on activities and mobility as people were asked to stay at home and schools moved to online learning. This may have increased risk of non-communicable disease by limiting recreational and transport-related physical activity. Building on an existing study, we assessed changes in self-reported and device-measured physical activity and travel behaviour before, during and after the peak of local COVID-19 outbreak and restrictions (March-July 2020). We examined beliefs in effectiveness of strategies to increase active and public transport after restrictions were reduced.

Methods

A longitudinal study of adult infrequent bus users (average ≤ 2 trips per week; n = 70; 67% women) in Hobart, Australia. One-week assessment periods at four separate timepoints (before, during, 0-3 months after, and 3-6 months after the peak restrictions period) involved wearing an accelerometer, daily transport diaries, online surveys and tracking bus smartcard boardings.

Results

Physical activity (especially among older participants), bus use and private motor vehicle use declined significantly during or 0-3 months after the peak restrictions period and returned to pre-restrictions levels by 3-6 months after the peak restrictions period, except bus use which remained significantly lower. Retrospective surveys overstated declines in bus use and active transport and self-reports understated declines in physical activity. Social distancing and improving service efficiency and frequency were seen as effective strategies for increasing bus use after restrictions but belief in effectiveness of distancing decreased over time.

Conclusions

When restrictions on mobility are increased, supportive health promotion measures are needed to prevent declines in physical activity, particularly for older adults. Public transport systems need capacity to implement temporary distancing measures to prevent communicable disease transmission. Providing convenient, flexible, and efficient options for public transport may help to replenish public transport use after restrictions are reduced.

Distinct patterns of adult transport-related physical activity (TRPA) behaviour exist independent of the TRPA behaviours of childhood: the childhood determinants of adult health study

BACKGROUND

Transport-related physical activity (TRPA) is recognised as a potential means of increasing total physical activity participation that may yield substantial health benefits. Public health campaigns focusing on promoting TRPA from a young age aim to develop life-long healthy habits. However, few studies have examined how TRPA changes across the lifecourse and whether childhood TRPA levels influence those observed later in life.

METHODS

Using the Australian Childhood Determinants of Adult Health study (baseline, 1985), latent class growth mixture modelling with adjustment for time-varying covariates was performed using four timepoints (ranging from 7 to 49 years) to assess behavioural patterns and retention of TRPA across the lifecourse. As child and adult adjusted TRPA measures could not be harmonised, trajectories of adult TRPA (n = 702) were instead identified, and log-binomial regression analysis was performed to determine whether childhood levels of TRPA (high/medium/low) influenced these trajectories.

RESULTS

Two stable groups of adult TRPA trajectories were identified: persistently low (n = 520; 74.2%), and increasingly high TRPA (n = 181; 25.8%). There was no significant relationship between childhood TRPA levels and patterns in adulthood (relative risk of high childhood TRPA yielding high adult TRPA trajectory membership = 1.06; 95% confidence interval = 0.95-1.09).

CONCLUSION

This study found childhood TRPA levels were not associated with TRPA patterns in adulthood. These findings suggest that while TRPA in childhood may have health, social, and environmental benefits, it does not appear to impact adult TRPA directly. Therefore, further intervention is required beyond childhood to promote the implementation of healthy TRPA behaviours into adulthood.

Association Between Commuting Time and Subjective Well-Being in Relation to Regional Differences in Korea

BACKGROUND

Long commuting times have a negative impact on mental health. However, few studies have explored the relationship between commuting time and well-being based on urbanization by region. Our study examines this relationship as well as the effect of regional differences on Korean workers.

METHODS

We used data from the sixth Korean Working Conditions Survey. Commuting time and occupational factors were assessed using a questionnaire, and subjective well-being was assessed using the World Health Organization-5 Well-Being Index. Regions were divided into the cities and the provinces based on Korea's administrative divisions. Logistic regression analysis was performed to investigate the association between commuting time and well-being. Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for well-being were estimated, using participants commuting time of < 20 minutes as a reference group.

RESULTS

The total number of workers was 29,458 (13,855 men, 15,603 women). We found higher aORs for low well-being among workers with long commuting times (aOR, 1.23; 95% CI, 1.11-1.36 and aOR, 1.28; 95% CI, 1.16-1.42 for 60-79 and ≥ 80 minutes, respectively). When stratified by sex and region, higher aORs for low well-being were found only in the workers who lived in cities.

CONCLUSION

Long commuting time was negatively associated with well-being in Korean wage workers living in the cities. Policies for reducing commuting time should be discussed to address the mental health of workers, especially those living in metropolitan cities.

Survey evidence on COVID-19 and its impact on rail commuting patterns in Great Britain

The COVID-19 pandemic saw a large proportion of the working population in the United Kingdom working from home for an extend period of time. In September 2021, a substantial number continued to work from home on a regular basis, a stark contrast to the situation pre-pandemic. Prior to 2020, although there was a growing trend for increased home working, this was still not a widespread practice across UK businesses, with the majority of staff working full-time from the employment location. The aim of this paper is to report the main changes in commuting and working patterns among commuters in Great Britain (GB) brought about by the COVID-19 pandemic with a special emphasis on the rail commuting market. The paper is informed by a panel survey of 3,892 GB respondents who commuted regularly to work prior to the pandemic in two waves. The first wave was conducted in Summer 2020 and focused on respondents' pre-pandemic travel patterns. The second wave was conducted in the Autumn 2021 and asked respondents about their current travel patterns. Although the focus was on rail travel, many of the conclusions of this paper are applicable to all modes of transport. Although a majority of pre-pandemic commuters have returned to commuting at least once per week to their place of work, there is a significant share of pre-pandemic commuters who are still working from home full-time. The return to the workplace has been slower among individuals who used to commute by rail compared to other modes. This is partially explained by current workplace arrangements being strongly linked with an individual's occupation and mode of transport. Individuals in office-based occupations are much more likely to work from home compared to those who work in other occupations. The pandemic has brought additional challenges to transport systems in addition to the reduced ridership level. Some of the emerging issues include managing post-pandemic peak travel volumes across a curtailed working week and the associated funding for peak capacity. Nonetheless, the research has highlighted some potential strategies to boost a faster recovery for travel demand.

How the COVID-19 pandemic changes daily commuting routines - Insights from the German Mobility Panel

The COVID-19 pandemic has had a major impact on everyday travel and, by extension, everyday commuting. During the pandemic, some people were able to work from home while others continued commuting. This study examines how commuting behavior changed between 2019 and 2020. In this study, we analyze panel data of the German Mobility Panel, a national household travel survey. We paint a broad picture of the characteristics and behavior of those who commuted during the pandemic. The analyses focus on the intra- and interpersonal differences and are presented in a mostly descriptive way. The results show that people with low income and a low level of education are primarily those who cannot work from home and do not have flexible working hours. The results further show that especially public transport has lost importance in daily commuting. However, those who commuted in 2019 and 2020 did not significantly change their commuting behavior regarding commuting time and commuting mode.

The impact of COVID-19 and policy measures on commuting in the Netherlands

In the Netherlands, one of the main goals of the Ministry of Infrastructure and Water Management is to increase accessibility and, at the same time, to reduce the negative externalities created by transport, such as congestion and greenhouse gas emissions. Within the Ministry, there was a clear need for a national and integrated monitoring instrument to measure the impact of policy measures on travel behaviour. To satisfy this need, we carried out a national traveller survey in 2019, 2020 and 2021. This paper describes some of the results of these surveys. Annual analyses include the trends in car ownership and mode choice for different purposes, with particular attention to commuting behaviour. It appears that travel time, convenience and flexibility play an important role in mode choice. Travel costs are less important and COVID-19 did not play a decisive role. It appears that free parking or availability of parking space has the most considerable impact on car use for commuting. In October 2019, employees travelled on average 3.8 days per week to work. In October 2020, mainly because of COVID-19, this number decreased to 2.9 travelling days and in October 2021, the number of travelled increased to 3.1. We examined the relationship between changes in car use for commuting between 2019, 2020 and 2021, and external developments in living and working, changes in the level of service of different transport modes and policy measures, both by the government and by employers. In addition, we investigated the influence of the COVID-19 pandemic on car use for commuting and this appeared to be an important factor, although external factors also play an important role. Finally, we estimated the effect of these changes in car use for commuting on congestion and CO₂ emissions.

A cross-cultural study of nonprofit self-organized ridesharing

Nonprofit ridesharing presents an underutilized opportunity for increasing transportation sustainability, as well as users' economic and social benefits, while reducing adverse environmental impacts. However, while app-based ridesharing has achieved only modest uptake, mostly limited to longer trips, in certain contexts, self-organized ridesharing (SORS) has shown significant achievements, even for the challenging short- and mid-range commuting trips. Still, knowledge regarding the key elements and mechanisms behind successful SORS is partial, hindering the ability to effectively leverage SORS diffusion and scaling potential. Following the premise that successful initiatives may provide learning opportunities, this study aims at narrowing this knowledge gap by performing a comparative cross-cultural systematic study of eight diverse SORS cases. The study uses a recently designed conceptual framework and multiple research methods (mainly online data exploration, personal interviews, observations, and documents analysis) to comprehensively examine SORSs' attributes and evolution stages and processes. Study findings highlight repeated patterns as well as the role of context, official actors, and local practices in shaping initiative's dynamics towards success. The study offers general and specific policy recommendations for supporting the early development, growth, and diffusion of SORS, as well as reflections on post pandemic ridesharing.

Age and domestic migration effects on workers' commuting distance

Do older workers, including those that work beyond age 65, have different commuting patterns than their younger counterparts? With a focus on older working adults, including those that continue to work beyond age 65, this paper examines the relationship between migration, residential location, and commute distance within Toronto's commuter shed. The study utilizes data from the master file of the 2016 Canadian Census, allowing migrants to be disaggregated by duration of residence. Results indicate that living in rural areas and being a recent migrant are significantly associated with longer commutes. Furthermore, findings demonstrate that the commute distance of very recent migrants (those who migrated in the year immediately prior to the census) and individuals who moved to rural areas have the longest commute distances. As residential duration increases, commute distance decreases. Older workers have similar commuting behaviors as younger workers, although older workers who recently migrated have some of the longest commute distances as well.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11116-022-10341-5.

Theory of planned behaviour, psychological stressors and intention to avoid violating traffic rules: A Multi-Level modelling analysis

This study applies a multilevel model approach to test the predictive effect of the theory of planned behaviour (TPB) plus moral norm, past behaviour and crash history to account for intentions to avoid traffic violations within the context of commuting to or from work. This study also extended the theory by adding psychological stressors of perceived stress and work-family conflict. In this study, we systematically tested the direct and mediated models. A sample of Malaysian drivers (N = 482; 44.6% were men and 55.4% women), with the average age of 36.7 years (SD = 10.0) was surveyed. The self-report questionnaire contained multiple observations nested within individual drivers, with respect to 3 different driving violations. As predicted, multi-level modelling showed that within-person predictor variables of all the TPB components emerged as independent predictors, with injunctive norm being the most predictive variable, followed by self-efficacy and cognitive attitude. Intention was also predicted by moral norms and crash history. Between-person variables, gender, commuting hours and work-family conflict also had direct influences on intention (i.e., men and those with longer commuting hours and higher work-family conflict reported lower intentions). Substantial support for the mediation model was found, confirming that stressors indirectly influence intentions through effects on the social cognitive components. The implications of the linkage between the social cognition and stressors for developing potential broader interventions focusing on multiple violation behaviours and designing appropriate safety policies to reduce commuting crashes are discussed.

How can ventilation be improved on public transportation buses? Insights from CO2 measurements

Measurements of CO₂ and counting of occupants were carried out in 37 public bus trips during commuting rush hours in Barcelona (NE Spain) with the aim of evaluating parameters governing ventilation inside the vehicles and proposing actions to improve it. The results show that CO₂ concentrations (1039 and 934 ± 386 ppm, as average and median, during rush hours but with average reduced occupancy due to the fair to be infected by SARS-CoV-2 during the measurement period, and measured in the middle of the busses) are in the lower range of values recorded in the literature for public buses, however an improvement in ventilation is required in a significant proportion of the journeys. Thus, we found better ventilation in the older Euro 3+ (retrofitted with filter traps and selective catalytic reduction) and Euro 5 buses (average 918 ± 257 ppm) than in the hermetically closed new Euro 6 ones (1111 ± 432 ppm). The opening of the windows in the older buses yielded higher ventilation rates (778 ± 432 ppm). The opening of all doors at all stops increases the ventilation by causing a fall in concentrations of 200-350 ppm below inter-stop concentrations, with this effect typically lasting 40-50 s in the hermetically closed new Euro 6 hybrid buses. Based on these results a number of recommendations are offered in order to improve ventilation, including measurement of CO₂ and occupancy, and installation of ventilation fans on the top of the hermetically closed new buses, introducing outdoor air when a given concentration threshold is exceeded. In these cases, a CO₂ sensor installed in the outdoor air intake is also recommended to take into account external CO₂ contributions.

Telework, Wages, and Time Use in the United States

Using data on full-time wage and salary workers from the 2017-2018 American Time Use Survey Leave and Job Flexibilities Module, we estimate hourly wage differentials for teleworkers and compare how workers allocate their time over the day when they work from home rather than the office. We find that some teleworkers earn a wage premium, but it varies by gender, parental status, and teleworking intensity. Fathers who telework earn more than fathers in office-based jobs, regardless of teleworking intensity. Women without children who telework occasionally earn more than their office counterparts. In industries and occupations where telework is more prevalent, mothers who work from home most days of the week pay a wage penalty compared to mothers in office-based jobs. Using time diaries, we find differences in work patterns and hours across worker groups that could drive these teleworker wage differentials. Most teleworkers work less on home days; however, those who earn wage premiums are working longer hours on weekdays, regardless of their work location. When teleworking, mothers experience more interruptions in their workdays than other workers, which could have negative effects on their productivity. We also find that teleworkers spend less time on commuting and grooming activities but more time on leisure activities and with family on work-at-home days than on office days, and female teleworkers spend more time sleeping and on household production activities.

Commute distance and jobs-housing fit

Anecdotal evidence suggests that the affordable housing crisis is forcing households to seek lower cost housing in the outer reaches of major metropolitan areas, helping to explain recent increases in commute distance. To test this relationship, we use spatial regression to examine the relationship between the availability of affordable housing in close proximity to jobs (jobs-housing fit) and commute distance in the Los Angeles metropolitan area. The analysis draws on 2015 Longitudinal Employer-Household Dynamics (LEHD) Origin-Destination Employment Statistics (LODES) by workplace supplemented with data from the 2013-2017 5-Year American Community Survey on affordable housing units. We find substantial variation in jobs-housing fit across Los Angeles neighborhoods. The imbalance is greatest in higher-income neighborhoods located along the coast and in Orange County, south of Los Angeles. Controlling for other determinants of commute distance, a higher ratio of jobs to affordable housing is associated with longer distance commutes. To address growing commute distances, policymakers must greatly expand and protect the supply of long-term rental housing particularly in job-rich neighborhoods.

Associations of neighborhood built, safety, and social environment with walking to and from school among elementary school-aged children in Chiba, Japan

BACKGROUND

Although it is globally known that Japan has high prevalence of active school travel among children, there are few international studies on Japanese children's school travel. Moreover, only few studies have focused on the differences in their mode of travel between to-school and from-school. This study examined the associations of neighborhood built, safety, and social environments with walking to/from school among elementary school-aged children in Chiba, Japan.

METHODS

We conducted an online survey with 1545 parents of children aged 6-12 years residing in Chiba between 25 and 27 November 2020 during the COVID-19 pandemic. A neighborhood was defined as the area of a postcode provided by the participants. Each neighborhood environment was assessed based on the built environment (new town designation, walkability, distance to school, population density), social environment (neighborhood cohesion and connection), and safety (CCTVs, a road section for walking alone, safety volunteers). Neighborhood walkability was measured using subscales of the Neighborhood Environment Walkability Scale (youth and abbreviated versions) including crime safety and traffic safety. Parents' perceived influence of COVID-19 on school commuting and after-school activities were also included in the model as covariates. Walking to and from school were separately analyzed using multinomial logistic regressions, where new towns and walkability were computed separately as explanatory variables.

RESULTS

Four fifths of children walked to and from school daily. Walking to school was positively associated with crime safety, neighborhood connections, and schools sited in new towns. Walking from school had positive associations with traffic safety, neighborhood cohesion, and CCTVs, but negative associations with safety volunteers and after-school activities. The presence of a section for walking alone and perceived influence of COVID-19 had negative associations with walking to and from school.

CONCLUSIONS

Recent social changes such as declining birthrate, decline in public elementary schools, and increasing after-school activities may change parental attitudes toward children's walking to/from school, and subsequently, their mode of school travel over time. To maintain the high prevalence of walking to/from school in Japan, multidisciplinary approaches involving different stakeholders from education, public health, and urban planning are required to overcome sectionalism and support this behavior in the long term.

A data-driven analysis of the potential of public transport for German commuters using accessibility indicators

Background

A significant mode shift will be required in order to meet the ambitious greenhouse gas emissions reduction targets in Germany and elsewhere. Such a mode shift can only be achieved by a combination of drastic push and pull measures. Getting commuters to switch modes might be particularly difficult and have a negative impact on their access to employment and welfare.

Methodology

We investigate the potential for a mode shift from car to public transport for German commuters using a data-driven approach based mainly on open data sources that avoids complex transport model runs. Different datasets on the home and workplace location of all employees in Germany are consolidated to create an origin-destination commuter matrix at traffic analysis zone level. The commuter matrix is merged with travel time data for car and public transport to calculate a spatially disaggregated and mode-specific measure of accessibility. The comparison of accessibility by car and public transport is used to derive the potential for a mode shift and identify potential challenges and barriers.

Results

Public transport accessibility to workplaces is poorer across the country compared to access by car. On average, public transport travel times are almost three times higher than the corresponding car travel times. The differences in accessibility are largely independent of the region type. Results are validated by an independent dataset from a household travel survey. Based on these results, the potential for a mode shift appears to be very low.

Commute trips in Norwegian cities: Data combining trip characteristics and revealed mode choice

Most transport mode choice studies rely on subjective responses to hypothetical questions (stated preference), or on revealed preferences. In stated preference studies, trip characteristics are exact, but there is a range of sources of errors and biases in the responses. Revealed preference surveys suffer the opposite: The choice is exact (i.e. observed) but trip attributes are uncertain – and even more uncertain when it comes to transport modes not chosen. Our dataset goes a long way in solving these problems. The data set combines real travel behaviour and mode choice data from the Norwegian National Transport Survey (NTS) with trip characteristics collected from Google maps travel planner. From the NTS, we have extracted all commute trips conducted by either private car or public transport (PT) into ten major cities in Norway with exact origin and destination coordinates. The NTS data also comprises information about age, gender, household, income and car availability. From Google maps, we have extracted trip characteristics for these trips – for both the mode chosen and the mode not chosen. This data includes total travel time, the number of interchanges, wait time, walk time, and in-vehicle time. This data can be used to study how different trip characteristics influence the probability of choosing PT over private car on commute journeys.

Commuter types identified using clustering and their associations with source-specific PM2.5

Traffic-related fine particulate matter air pollution (tr-PM_2.5) has been associated with adverse health outcomes such as cardiopulmonary morbidity and mortality, with in-vehicle tr-PM_2.5 exposure contributing to total personal pollution exposure. Trip characteristics, including time of day, day of the week, and traffic congestion, are associated with in-vehicle PM_2.5 exposures. We hypothesized that some commuter characteristics, such as whether commuters travel primarily during rush hour, would also be associated with increased tr-PM_2.5 exposures. The commute data consisted of unscripted personal vehicle trips of 46 commuters in the Washington, D.C. metro area over 48-h, with a total of 320 trips. We identified commuter types using sparse K-means clustering, which identifies the hours throughout the day important for clustering commuters. Source-specific PM_2.5 over 48 h was estimated using Positive Matrix Factorization. Linear regression was used to estimate differences in source-specific PM_2.5 by commuter cluster. Two commuter clusters were identified using the clustering approach: rush hour commuters, who primarily travelled during rush hour, and sporadic commuters, who travelled throughout the day. The hours given the largest weights by sparse K-means were 7-8 a.m. and 6-7 p.m., corresponding to peak travel times. Integrated black carbon (BC) was higher for rush hour commuters (median = 3.1 μg/m³ (IQR = 1.5)) compared to sporadic commuters (2.0 μg/m³ (IQR = 1.9)). Mobile PM_2.5, consisting primarily of tailpipe emissions and brake/tire wear, was also higher for rush hour commuters (2.9 μg/m³ (IQR = 1.6)) compared to sporadic commuters (2.1 μg/m³ (IQR = 2.4)), though this difference was not statistically significant in regression models. Estimated differences between commuter types for secondary/mixed PM_2.5 and road salt PM_2.5 were smaller. Further research may elucidate whether commuter characteristics are an efficient way to identify individuals with highest tr-PM_2.5 exposures associated with commuting and to develop effective mitigation strategies.

Individual, social, and environmental factors associated with active transportation commuting during the COVID-19 pandemic

OBJECTIVE

Physical inactivity is a major public health concern. Though active transportation through bicycling and walking can increase physical activity and thereby positively affect health, factors that influence people's decisions to commute using active transportation modes remain underexplored and often fail to capture equity-related barriers. Increases in active transportation during the COVID-19 pandemic call for a better understanding of these influences. This study examines the commute mode choices of essential workers in Philadelphia, Pennsylvania, USA to explore the extent to which active transportation to work is explained by individual, social, and environmental factors and whether active transportation choices reflect inequalities.

METHODS

Drawing on the theory of planned behavior and the social-ecological model, this study utilizes data from an online survey (N = 213) completed between June and August 2020. Bivariate analyses compare respondents who commuted using active transportation modes to those who did not using chi-square and ANOVA tests. A series of logistic regression models using forward stepwise selection, controlling for demographic characteristics and commute distance, identify salient individual, social, and environmental factors associated with active transportation.

RESULTS

Nearly half of respondents changed their commute mode during the pandemic, most often to limit exposure to COVID-19. The full model, accounting for 54% of variation in active transportation commuting, indicated significantly lower odds of active transportation use among non-white (Odds Ratio [OR]: 0.155) respondents and those who reported time constraints (OR: 0.450), concerns about safety from traffic (OR: 0.482), and greater satisfaction with community support for bicycling and pedestrian issues (OR: 0.551) and significantly higher odds among those who reported safety concerns around germs (OR: 1.580).

CONCLUSIONS

Structural and social investments that make bicycling and walking safer commuting alternatives during COVID-19 could protect essential works and contribute to sustained behavior change. Community engagement is essential for implementation efforts.

Socioeconomic inequalities in physical activity in Brazil: a pooled cross-sectional analysis from 2013 to 2019

BACKGROUND

Information on socioeconomic inequalities in physical activity over time is sparse in low- to middle-income countries. In this study, we examined trends in physical activity educational inequalities in adults from Brazil between 2013 and 2019.

METHODS

We analyzed data from seven cross-sectional studies including 359,038 adults (≥ 18 years) from the VIGITEL study conducted annually from 2013 to 2019. Participants responded to a questionnaire about physical activity (total, leisure, and commuting). Educational inequalities by sex and skin color were assessed through absolute (slope index of inequality - SII) and relative measures of inequality (concentration index - CIX).

RESULTS

We found large absolute and relative inequalities for leisure-time physical activity, favoring those with higher educational attainment (SII₂₀₁₉ = 35.4; CIX₂₀₁₉ = 11.82). Active commuting was more prevalent in intermediate education groups, with a slight inequality toward the less educated group (SII₂₀₁₉ = -2.8; CIX₂₀₁₉ = -0.4). From 2013 to 2019, the absolute educational inequality in physical activity (total, leisure, and commuting) remained unchanged; however, the relative inequality gap narrowed for total physical activity (CIX: 8.4 in 2013 to 5.5 in 2019) and leisure-time physical activity (CIX: 18.3 in 2013 to 11.8 in 2019). Educational inequality increased in leisure-time physical activity among women and non-white individuals, while it reduced among men and white individuals; for active commuting, inequality decreased among women, and increased among men and white individuals.

CONCLUSIONS

Inequality in total physical activity and leisure-time physical activity favors the most educated groups in Brazil. Over time, relative educational inequality decreased for total and leisure-time physical activity, while no progress was found for absolute inequality.

Association between extreme ambient temperatures and general indistinct and work-related road crashes. A nationwide study in Italy

Despite the relevance of road crashes and their impact on social and health care costs, the effects of extreme temperatures on road crashes risk have been scarcely investigated, particularly for those occurring in occupational activities. A nationwide epidemiological study was carried out to estimate the risk of general indistinct and work-related road crashes related with extreme temperatures and to identify crash and occupation parameters mostly involved. Data about road crashes, resulting in death or injury, occurring during years 2013-2015 in Italy, were collected from the National Institute of Statistics, for general indistinct road crashes, and from the compensation claim applications registered by the national workers' compensation authority, for work-related ones. Time series of hourly temperature were derived from the results provided by the meteorological model WRF applied at a national domain with 5 km resolution. To consider the different spatial-temporal characteristics of the two road crashes archives, the association with extreme temperatures was estimated by means of a case-crossover time-stratified approach using conditional logistic regression analysis, and a time-series analysis, using over-dispersed Poisson generalized linear regression model, for general indistinct and work-related datasets respectively. The analyses were controlled for other covariates and confounding variables (including precipitation). Non-linearity and lag effects were considered by using a distributed lag non-linear model. Relative risks were calculated for increment from 75th to 99th percentiles (hot) and from 25 to first percentile (cold) of temperature. Results for general indistinct crashes show a positive association with hot temperature (RR = 1.12, 95 % CI: 1.09-1.16) and a negative one for cold (RR = 0.93, 95 % CI: 0.91-0.96), while for work-related crashes a positive association was found for both hot and cold (RR = 1.06 (95 % CI: 1.01-1.11) and RR = 1.10 (95 % CI: 1.05-1.16). The use of motorcycles, the location of accident (urban vs out of town), presence of crossroads, as well as occupational factors like the use of a vehicle on duty were all found to produce higher risks of road crashes during extreme temperatures. Mitigation and prevention measures are needed to limit social and health care costs.

Is the built-environment at origin, on route, and at destination associated with bicycle commuting? A gender-informed approach

There is limited evidence on the gender differences and location-specific built-environment factors associated with bicycling in Latin American cities. This study aimed to assess commuting in Bogotá by (1) analyzing the gender-specific trend of the standardized number of bicycle commuters during 2005-2017; and (2) assessing the socio-demographic, community, built-environment and natural factors associated with bicycle commuting stratified by gender. This secondary-data analysis included data from the Household Travel Surveys and Multipurpose Surveys to calculate the number of bicycle commuters per habitant from 2005 to 2017 by gender. We assessed the socio-demographic and built-environment factors fitting generalized additive models stratified by gender using the 2015 Household Travel Survey. Although both women and men increased the standardized number of bicycle commuters, male commuters show a steeper trend than women, evidencing the widening gender gap in bicycle commuting over time. Bicycle commuting was negatively associated with household motor vehicle ownership, steeper terrain slope, longer commute distance, and scarce low-stress roads at trip origin and route. Among women, the availability of bike paths at the trip destination was positively associated with bicycling, while age and being a student were negatively associated with bicycling. Among men, living in areas with the lowest socio-economic status was positively associated with bicycling, while having a driver's license and living close to bus rapid transit stations were negatively associated with bicycling. In conclusion, bicycle and transport infrastructure play different roles in commuting by bicycle by gender and trip stages (origin - route - destination).

Social inequalities in mobility during and following the COVID-19 associated lockdown of the Madrid metropolitan area in Spain

Spain has been one of the most affected regions by the COVID-19 worldwide, and Madrid its most affected city. In response to this, the Spanish government enacted a strict lockdown in late March 2020, that was gradually eased until June 2020. We explored differentials in mobility by area-level deprivation in the functional area of Madrid, before, during, and after the COVID-19 lockdown. We used cell phone-derived mobility indicators (% of the population leaving their area) from the National Institute of Statistics (INE), and a composite measure of deprivation from the Spanish Society of Epidemiology (SEE). We computed changes in mobility with respect to pre-pandemic levels, and explored spatial patterns and associations with deprivation. We found that levels of mobility before COVID-19 were slightly higher in areas with lower deprivation. The economic hibernation period resulted in very strong declines in mobility, most acutely in low deprivation areas. These differences weakened during the re-opening, and levels of mobility were similar by deprivation once the lockdown was completely lifted. Given the existence of important socioeconomic differentials in COVID-19 exposure, it is key to ensure that these interventions do not widen existing social inequalities.

Determinants of bicycle commuting and the effect of bicycle infrastructure investment in London: Evidence from UK census microdata

Worldwide, concern about physical inactivity and excessive car dependence has encouraged ambitious targets and policies to promote cycling. But policy making is hindered by limited knowledge about why cycling prevalence and trends vary greatly between different geographic areas (e.g. in London (UK) <1% cycle to work in Harrow compared to>15 % in Hackney) and individuals (e.g. by age or gender). The role of cycle infrastructure investment in explaining part of these patterns and trends is also unknown. We linked individual-level data on 317,117 London commuters (including 11,199 cyclists) in the 2001 and 2011 UK census to relevant geographic data, including on area-level cycling infrastructure investment during the period. Whilst cycle commuting increased over time on average, concentration curves and indices demonstrated that in contrast with England as a whole, cycling in London shifted from being dominated by commuters with lower socioeconomic status to commuters with higher socioeconomic status. In our first set of regression analyses, we showed that observed differences and time trends in cycling prevalence were partially explained by area-level differences in topography, greenspace, footpaths and crime levels and by differences and changes in population structures. In the second, we conducted a cost-effectiveness analysis which showed that expenditure on cycling infrastructure was associated with increased cycling at a marginal rate of £4915 per additional commuter cyclist, with some variation between groups: ethnic minorities were more responsive, and females, older people and those with lower socioeconomic status appeared less responsive. If planned increases in expenditure in England for the period 2020-25 were as cost-effective, and were sustained for the whole decade, our study suggests that commuter cycling prevalence could increase in England by 0.5 to 1.1 percentage points (this equates to a 16% to 34% increase in commuter cycling prevalence if compared to 2011 levels). More research is necessary to assess the impact on broader measures of cycling, active travel and overall physical activity, and to determine whether such expenditure constitutes good or equitable value for money.

Air quality around schools: Part I - A comprehensive literature review across high-income countries

Children are particularly vulnerable to the detrimental health impacts of poor air quality. In the UK, recent initiatives at local council level have focussed on mitigating children's air pollution exposure at school. However, an overview of the available evidence on concentration and exposure in school environments - and a summary of key knowledge gaps - has so far been lacking. To address this, we conducted a review bringing together recent academic and grey literature, relating to air quality in outdoor school environments - including playgrounds, drop-off zones, and the school commute - across high-income countries. We aimed to critically assess, synthesise, and categorise the available literature, to produce recommendations on future research and mitigating actions. Our searches initially identified 883 articles of interest, which were filtered down in screening and appraisal to a final total of 100 for inclusion. Many of the included studies focussed on nitrogen dioxide (NO₂), and particulate matter (PM) in both the coarse and fine fractions, around schools across a range of countries. Some studies also observed ozone (O₃) and volatile organic compounds (VOCs) outside schools. Our review identified evidence that children can encounter pollution peaks on the school journey, at school gates, and in school playgrounds; that nearby traffic is a key determinant of concentrations outside schools; and that factors relating to planning and urban design - such as the type of playground paving, and amount of surrounding green space - can influence school site concentrations. The review also outlines evidence gaps that can be targeted in future research. These include the need for more personal monitoring studies that distinguish between the exposure that takes place indoors and outdoors at school, and a need for a greater number of studies that conduct before-after evaluation of local interventions designed to mitigate children's exposure, such as green barriers and road closures. Finally, our review also proposes some tangible recommendations for policymakers and local leaders. The creation of clean air zones around schools; greening of school grounds; careful selection of new school sites; promotion of active travel to and from school; avoidance of major roads on the school commute; and scheduling of outdoor learning and play away from peak traffic hours, are all advocated by the evidence collated in this review.

Chemical characterisation of particulate matter in urban transport modes

Traffic is a main source of air pollutants in urban areas and consequently daily peak exposures tend to occur during commuting. Personal exposure to particulate matter (PM) was monitored while cycling and travelling by bus, car and metro along an assigned route in Lisbon (Portugal), focusing on PM2.5 and PM10 (PM with aerodynamic diameter <2.5 and 10 µm, respectively) mass concentrations and their chemical composition. In vehicles, the indoor-outdoor interplay was also evaluated. The PM2.5 mean concentrations were 28 ± 5, 31 ± 9, 34 ± 9 and 38 ± 21 µg/m³ for bus, bicycle, car and metro modes, respectively. Black carbon concentrations when travelling by car were 1.4 to 2.0 times higher than in the other transport modes due to the closer proximity to exhaust emissions. There are marked differences in PM chemical composition depending on transport mode. In particular, Fe was the most abundant component of metro PM, derived from abrasion of rail-wheel-brake interfaces. Enhanced concentrations of Zn and Cu in cars and buses were related with brake and tyre wear particles, which can penetrate into the vehicles. In the motorised transport modes, Fe, Zn, Cu, Ni and K were correlated, evidencing their common traffic-related source. On average, the highest inhaled dose of PM2.5 was observed while cycling (55 µg), and the lowest in car travels (17 µg). Cyclists inhaled higher doses of PM2.5 due to both higher inhalation rates and longer journey times, with a clear enrichment in mineral elements. The presented results evidence the importance of considering the transport mode in exposure assessment studies.

Associations between socioeconomic status and ultrafine particulate exposure in the school commute: An environmental inequality study for Toronto, Canada

Ultrafine particulate matter (UFP) air pollution is unevenly distributed across urban environments. Disparities in routine activity patterns, such as the exposure risk we face at work or on the commute, can contribute to chronic exposure-related health outcomes that place excess burdening on vulnerable population groups. In Canada, there is disagreement in the literature on the nature of these exposure-related inequalities, and our understanding of disparities associated with specific activity patterns such as commuting is limited. In the context of UFP specific exposure, these relationships are almost entirely unexplored in the environmental inequality literature. Our study presents an exploratory analysis of UFP exposure patterns in Toronto, Canada. We examined UFP dosage disparities experienced by children during routine school commutes. We estimated single trip dosages that accounted for variation in ambient UFP concentration, route morphology (distance, slope) and their effect on inhalation rate and trip duration. We aggregated these values at the dissemination-area level and collected socioeconomic status descriptors from the 2016 census. Our OLS model showed significant spatial autocorrelation (MI = 0.59, p < 0.001), and we instead applied a spatial error model to account for spatial effects in our dataset. We identified significant associations related to median income (β = -0.087, p < 0.05), government transfer dependence (β = -0.107, p < 0.005), immigration status (β = 0.119, p < 0.001), and education rates (β = -0.059, p < 0.05). Our results diverged from other pollutants in Toronto-based literature and could indicate that UFPs exhibit unique patterns of inequality. Our findings suggest a need to further study UFP dosage from an environmental inequality perspective.

Regional Patterns and Determinants of Commuting Between Rural and Urban India

Despite an increase in the number of workers commuting between rural and urban areas, much of the literature on worker mobility continues to be migration centric. This paper establishes the importance of rural-urban commuting in India. As per estimates from Periodic Labour Force Survey 2018-2019, an estimated 18.8 million individuals living in rural are working in urban India and the share of earnings from urban in total non-farm rural earnings is 19.3%. Among all rural workers, 7.3% are rural-urban commuters while only 2.1% of urban workers are urban-rural commuters. We document large variations at the sub-national level. Our results from a multinomial model to understand the factors associated with commuting highlight the importance of lagged regional unemployment rate. A high rural unemployment rate acts as a push factor, and a low urban unemployment rate acts as a pull factor for rural-urban commuting. The urbanness of occupations in a region is also an important correlate of commuting. The paper concludes by highlighting the need to prioritize questions in India's labour force survey that would help understand the nature of labour mobility and strength of rural-urban linkages.

Assessing schoolchildren's exposure to air pollution during the daily commute - A systematic review

Air pollution is mostly caused by emissions from human activities, and exposure to air pollution is linked with numerous adverse human health outcomes. Recent studies have identified that although people only spend a small proportion of time on their daily commutes, the commuter microenvironment is a significant contributor to their total daily air pollution exposure. Schoolchildren are a particularly vulnerable cohort of the population, and their exposure to air pollution at home or school has been documented in a number of case studies. A few studies have identified that schoolchildren's exposure during commutes is linked with adverse cognitive outcomes and severe wheeze in asthmatic children. However, the determinants of total exposure, such as route choice and commute mode, and their subsequent health impacts on schoolchildren are still not well-understood. The aim of this paper is to review and synthesize recent studies on assessing schoolchildren's exposure to various air pollutants during the daily commute. Through reviewing 31 relevant studies published between 2004 and 2020, we tried to identify consistent patterns, trends, and underlying causal factors in the results. These studies were carried out across 10 commute modes and 12 different air pollutants. Air pollution in cities is highly heterogeneous in time and space, and commuting schoolchildren move through the urban area in complex ways. Measurements from fixed monitoring stations (FMSs), personal monitoring, and air quality modeling are the three most common approaches to determining exposure to ambient air pollutant concentrations. The time-activity diary (TAD), GPS tracker, online route collection app, and GIS-based route simulation are four widely used methods to determine schoolchildren's daily commuting routes. We found that route choices exerted a determining impact on schoolchildren's exposure. It is challenging to rank commute modes in order of exposure, as each scenario has numerous uncontrollable determinants, and there are notable research gaps. We suggest that future studies should concentrate on examining exposure patterns of schoolchildren in developing countries, exposure in the subway and trains, investigating the reliability of current simulation methods, exploring the environmental justice issue, and identifying the health impacts during commuting. It is recommended that three promising tools of smartphones, data fusion, and GIS should be widely used to overcome the challenges encountered in scaling up commuter exposure studies to population scales.

Estimating exposure to traffic-related PM2.5 for women commuters using vehicle and personal monitoring

Exposure to traffic-related fine particulate matter air pollution (tr-PM_2.5) has been associated with adverse health outcomes including preterm birth and low birthweight. In-vehicle exposure to tr-PM_2.5 can contribute substantially to total tr-PM_2.5 exposure. Because average commuting habits of women differ from men, a research gap is estimating in-vehicle tr-PM_2.5 exposures for women commuters. For 46 women commuters in the Washington, D.C. metro area, we measured personal exposure to PM_2.5 during all vehicle trips taken in a 48-h sampling period. We also measured 48-h integrated PM_2.5 chemical constituents including black carbon and zinc. We identified trip times using vehicle monitors, specifically on-board diagnostics data loggers and dashboard cameras. For 386 trips, we estimated associations between PM_2.5 exposure and trip characteristics using linear mixed models accounting for participant, day, and time of day. Additionally, we estimated associations between rush hour trip PM_2.5 and 48-h integrated PM_2.5 chemical constituents using linear models. Exposure to PM_2.5 during trips was 1.9 μg/m³ (95% confidence interval (CI): 0.9, 2.9) higher than non-trip exposures and rush hour trip exposures were 3.2 μg/m³ (95% CI: 1.8, 4.6) higher than non-trip exposures on average. We did not find differences in PM_2.5 exposure by trip length. Although concentrations of tr-PM_2.5 chemical constituents were generally positively associated with rush hour trip PM_2.5, associations were weak indicating that other settings contribute to total tr-PM_2.5 exposure. Our study demonstrates the utility of combining vehicle monitors and personal PM_2.5 monitors for estimating personal exposure to tr-PM_2.5. Future work will investigate whether additional data collected by vehicle monitors, such as traffic and speed, can be leveraged to better understand tr-PM_2.5 exposure among commuters.

Relationship between different domains of physical activity and positive mental health among young adult men

Background

There is growing evidence on positive effects of physical activity (PA) on mental health. However, the focus of previous research on this relationship has typically been on mental health from the perspective of mental health problems rather than from the perspective of mental wellbeing. Further, previous research has commonly focused rather on leisure time PA without evidence on the role of other domains of PA. The aim of the present cross-sectional study was to investigate the relationship between positive mental health (PMH) and different domains of PA in young Finnish men. The secondary aim was to examine the reasons for physical inactivity among individuals with a low level of PMH.

Methods

Positive mental health (measured with Short Warwick-Edinburgh Mental Wellbeing Scale, SWEMWBS), self-reported leisure time, occupational and commuting PA as well as reasons for physical inactivity were measured using questionnaires (n = 456, mean age 29 years) among young Finnish males. Logistic regression modelling was used to generate odds for low and high levels of positive mental health for different levels of PA and sociodemographic variables.

Results

A weak positive association between leisure time PA and PMH was found in men with a low level of PMH (OR = 0.33, 95% CI 0.13–0.86). No association was found in the domains of commuting and occupational PA. Multivariate logistic regression analysis showed lower level of leisure time PA, unemployment and being single independently predicting low level of PMH. No associations were found between any domains of PA and high level of PMH. The most common reasons for physical inactivity among men with a low level of PMH were lack of interest (28%) and unwillingness to practise sports alone (27%).

Conclusions

The relationship between physical activity and positive mental health seems to vary between different domains of physical activity. The findings highlight the important role of leisure time physical activity, particularly in men with a low level of positive mental health. Strategies aimed at increasing physical activity for mental health benefits should focus particularly on providing opportunities for leisure time physical activity involving social interactions for men with lower mental wellbeing.

Migration, Commuting, or a Second Home? Insights from an Experiment Among Academics

In the last decades, more complex types of residential mobility, such as second homes, arose while one-way relocations declined. Existing studies that address migration and commuting as being substitutes often face problems of endogeneity or lack of data regarding decision-making on different types of residential mobility. In contrast, we investigate decision-making on migration, commuting, and establishing a second home by using a factorial survey experiment, which allows for the accounting of both endogeneity bias through randomisation and complexity in decision-making through treatment variation. Hypothetical job offers were presented to a sample of academic staff of a Swiss university (ETH Zurich) in order to examine the intended types of residential mobility and their drivers. Referring to the concept of loss aversion, the utility of a second home can exceed the joint utilities of migration and commuting particularly when the total loss of the current residence bears intolerable costs caused by location-specific capital, and daily commuting bears prohibitive costs caused by a lengthy distance. Analyses show that the migration intention is mainly caused by low migration and high transition costs and the commuting intention is mainly caused by low transition costs and high migration costs. Establishing a second home is indeed more intended with simultaneously higher migration and transition costs. In sum, a second home may be understood as a substitute for one-way relocations and daily commuting, yet primarily under conditions of extremely high or irreversible migration costs and unsustainable transition costs.

Does free public transit increase physical activity and independent mobility in children? Study protocol for comparing children's activity between two Finnish towns with and without free public transit

BACKGROUND

Children's habitual physical activity, including active travel and catching public transit (walking and cycling to and from destinations), and independent mobility (mobility without an adult) have decreased. Public transit trips are physically active and can provide access to hobbies independent of parents, but there is no device-measured data about children's total physical activity time following the introduction of free public transit. Our aim is to compare physical activity and independent mobility between children living in two Finnish towns, one with a recently introduced free public transit system, and the other without free public transit.

METHODS

The city of Mikkeli has provided free public transit for all comprehensive school children since 2017. Various districts from Mikkeli, and the reference town of Kouvola (towns from South-Eastern Finland with a comparative population size and geographical structure), are selected based on their accessibility and the availability of public transit services. Samples of 10-12-year-old children will be recruited through primary schools. We will compare moderate-to-vigorous physical activity time, sitting time (a thigh-worn Fibion® device) and independent mobility (a participatory mapping method, PPGIS) of children: 1) who live in towns with and without free public transit, 2) who live and go to school in districts with high vs. low perceived and objective access to free public transit, and 3) who report using vs. not using free public transit. In addition, ethnography will be used to get insights on the social and cultural effects of the free public transit on children's and parent's everyday life.

DISCUSSION

There is a need for scalable solutions that can increase children's physical activity independent of their socioeconomic background or place of residence. This project will give information on how a political action to provide free public transit for children is associated with their total physical activity time and independent mobility patterns, therefore providing highly relevant information for political decision-making and for promoting independent physical activity in children.

Vehicle interior air quality conditions when travelling by taxi

Vehicle interior air quality (VIAQ) was investigated inside 14 diesel/non-diesel taxi pairs operating simultaneously and under normal working conditions over six weekday hours (10.00-16.00) in the city of Barcelona, Spain. Parameters measured included PM₁₀ mass and inorganic chemistry, ultrafine particle number (N) and size, lung surface deposited area (LDSA), black carbon (BC), CO₂, CO, and a range of volatile organic compounds (VOCs). Most taxi drivers elected to drive with windows open, thus keeping levels of CO₂ and internally-generated VOCs low but exposing them to high levels of traffic-related air pollutants entering from outside and confirming that air exchange rates are the dominant influence on VIAQ. Median values of N and LDSA (both sensitive markers of VIAQ fluctuations and likely health effects) were reduced to around 10⁴ #/cm³ and < 20 µm²/cm³ respectively under closed conditions, but more than doubled with windows open and sometimes approached 10⁵ #/cm³ and 240 µm²/cm³. In exceptional traffic conditions, transient pollution peaks caused by outside infiltration exceeded N = 10⁶ #/cm³ and LDSA= 1000 µm²/cm³. Indications of self-pollution were implicated by higher BC and CO levels, and larger UFP sizes, measured inside diesel taxis as compared to their non-diesel pair, and the highest concentrations of CO (>2 ppm) were commonly associated with older, high-km diesel taxis. Median PM₁₀ concentrations (67 µg/m³) were treble those of urban background, mainly due to increased levels of organic and elemental carbon, with source apportionment calculations identifying the main pollutants as vehicle exhaust and non-exhaust particles. Enhancements in PM₁₀ concentrations of Cr, Cu, Sn, Sb, and a "High Field Strength Element" zircon-related group characterised by Zr, Hf, Nb, Y and U, are attributed mainly to the presence of brake-derived PM. Volatile organic compounds display a mixture which reflects the complexity of traffic-related organic carbon emissions infiltrating the taxi interior, with 2-methylbutane and n-pentane being the most abundant VOCs, followed by toluene, m-xylene, o-xylene, 1,2,4-trimethylbenzene, ethylbenzene, p-xylene, benzene, and 1,3,5-trimethylbenzene. Internally sourced VOCs included high monoterpene concentrations from an air freshener, and interior off-gassing may explain why the youngest taxi registered the highest content of alkanes and aromatic compounds. Carbon dioxide concentrations quickly climbed to undesirable levels (>2500 ppm) under closed ventilation conditions and could stay high for much of the working day. Taxi drivers face daily occupational exposure to traffic-related air pollutants and would benefit from a greater awareness of VIAQ issues, notably the use of ventilation, to encourage them to minimise possible health effects caused by their working environment.

Drowsiness and driving performance on commuter trips

INTRODUCTION

Driver fatigue is a major road safety problem. While much is known about the effects of fatigue and the factors that contribute to it, fatigue on commuter trips has received comparatively little attention in road safety. Most interventions have focused on longer trips, while investigations of commuting have typically examined particular groups, such as shift workers.

METHOD

This study examined the effects of mild sleep deprivation on driving performance in simulated driving tasks in the morning and evening. Three groups of participants with different levels of sleep deprivation (Group 1: no deprivation; Group 2: two-hour deprivation; Group 3: four-hour deprivation) drove in a simulator for 45 min in the morning and evening, following a practice session the previous day.

RESULTS

Results showed that participants reported feeling more drowsy in the afternoon, and performance impairments (increased lane deviations) were most evident in the morning for those with sleep deprivation. Measurements of eye closure did not reflect drowsiness in participants, despite performance impairments.

PRACTICAL APPLICATIONS

These results suggest that mild levels of sleep deprivation (2 h), which many people regularly experience, can result in poor on-road performance, and that these effects are present in the morning, and on relatively short trips. These results warrant follow-up in naturalistic and on-road studies.

Cyclist exposure to black carbon, ultrafine particles and heavy metals: An experimental study along two commuting routes near Antwerp, Belgium

Urban environments typically exhibit large atmospheric pollution variation, in both space and time. In contrast to traditional monitoring networks suffering from a limited spatial coverage, mobile platforms enable personalized high-resolution monitoring, providing valuable insights into personal atmospheric pollution exposure, and the identification of potential pollution hotspots. This study evaluated personal cyclist exposure to UFPs, BC and heavy metals whilst commuting near Antwerp, Belgium, by performing mobile measurements with wearable black carbon (BC) and ultrafine particle (UFP) instruments. Loaded micro-aethalometer filterstrips were chemically analysed and the inhaled pollutant dose determined from the exhibited heart rate. Considerable spatial pollutant variation was observed along the travelled routes, with distinct contributions from spatial factors (e.g. traffic intersections, urban park and market) and temporary events. On average 300% higher BC, 20% higher UFP and changing elemental concentrations are observed along the road traffic route (RT), when compared to the bicycle highway route (BH). Although the overall background pollution determines a large portion of the experienced personal exposure (in this case 53% for BC and 40% for UFP), cyclists can influence their personal atmospheric pollution exposure, by selecting less exposed commuting routes. Our results, hereby, strengthen the body of evidence in favour of further policy investments in isolated bicycle infrastructure.

Source-specific pollution exposure and associations with pulmonary response in the Atlanta Commuters Exposure Studies

Concentrations of traffic-related air pollutants are frequently higher within commuting vehicles than in ambient air. Pollutants found within vehicles may include those generated by tailpipe exhaust, brake wear, and road dust sources, as well as pollutants from in-cabin sources. Source-specific pollution, compared to total pollution, may represent regulation targets that can better protect human health. We estimated source-specific pollution exposures and corresponding pulmonary response in a panel study of commuters. We used constrained positive matrix factorization to estimate source-specific pollution factors and, subsequently, mixed effects models to estimate associations between source-specific pollution and pulmonary response. We identified four pollution factors that we named: crustal, primary tailpipe traffic, non-tailpipe traffic, and secondary. Among asthmatic subjects (N = 48), interquartile range increases in crustal and secondary pollution were associated with changes in lung function of -1.33% (95% confidence interval (CI): -2.45, -0.22) and -2.19% (95% CI: -3.46, -0.92) relative to baseline, respectively. Among non-asthmatic subjects (N = 51), non-tailpipe pollution was associated with pulmonary response only at 2.5 h post-commute. We found no significant associations between pulmonary response and primary tailpipe pollution. Health effects associated with traffic-related pollution may vary by source, and therefore some traffic pollution sources may require targeted interventions to protect health.

Willingness to commute among future physicians: a multicenter cross-sectional survey of German medical students

Background

Many countries are faced with a decrease in physicians in non-urban areas. Especially for regions with decreasing populations, temporary solutions like commuting models might be a suitable option. So far, little is known about the willingness to commute among future physicians.

Methods

In this multicenter, cross-sectional survey, five years of medical students (8th to 10th semester) from three German universities (Charité Berlin, Halle, Leipzig) were questioned about their willingness to commute to work, the maximum acceptable commute time, and how several job-related factors might enhance the attractiveness of commuting.

Results

Altogether 1108 of 1203 (92.1%) students completed the questionnaire. For 55.9% of the participants it was imaginable to commute to a non-urban area in the future. The most important job-related factors that would increase the attractiveness of such a commuting model were remuneration of the commuting time, higher remuneration in general, working self-employed in a joint practice with 2–3 physicians, existence of a specifically qualified “supply assistant”, provision of a home office, good public transport connection, and a driver service. The maximum acceptable commute time was on average 39.0 min (one-way). If the way to work would be a salaried integral part of the normal working time, the participants stated they would accept traveling 51.2 min (one-way).

Conclusions

Most future physicians are open-minded regarding models of commuting. The attractiveness of such models can be increased mainly through higher remuneration, reduction of the physicians’ burden, and comfortable modes of transport.

Commuter exposure to fine and ultrafine particulate matter in Vienna

Mass concentrations PM10, PM2.5, PM1, particle number concentrations of ultrafine particles and lung deposited surface area were measured during commutes with a subway, tram, bus, car and bicycle in Vienna for the first time. Obtained data were examined for significant differences in personal exposure when using various transport modalities along similar routes. Mean PM2.5 and PM1 mass concentrations were significantly higher in the subway when compared to buses. Mean PM10, PM2.5 and PM1 mass concentrations were significantly higher in the subway when compared to cars using low ventilation settings. Particle number concentrations of ultrafine particles were significantly higher in trams when compared to the subway and lung deposited surface area was significantly greater on bicycles when compared to the subway. After adjusting for different vehicle speeds, exposure to PM10, PM2.5 and PM1 along the same route length was significantly higher in the subway when compared to cars while exposure to ultrafine particles and partly also lung deposited surface area was significantly higher in bus, tram and on bicycle when compared to the subway. Car and bus passengers could be better isolated from ambient fine particulate matter than passengers in the subway, where a lot of ventilation occurs through open windows and larger doors. Tram passengers and cyclists might be exposed to increased amounts of ultrafine particles and larger lung deposited surface area due to a closer proximity to road traffic. Comparing cumulative exposure along the same route length leads to different results and favors faster traffic modes, such as the subway.

Transit use and physical activity: Findings from the Houston travel-related activity in neighborhoods (TRAIN) study

Transportation-related physical activity can significantly increase daily total physical activity through active transportation or walking/biking to transit stops. The purpose of this study was to assess the relations between transit-use and self-reported and monitor-based physical activity levels in a predominantly minority population from the Houston Travel-Related Activity in Neighborhoods (TRAIN) Study. This was a cross-sectional analysis of 865 adults living in Houston, Texas between 2013 and 2015. The exposure variable was transit-use (non-users, occasional users, and primary users). Self-reported and accelerometer-determined physical activity were the outcomes of interest. Regression models adjusting for age, sex, race/ethnicity, and other covariates of interest were built to test the hypothesis that transit user status was directly associated with 1) minutes of moderate-intensity physical activity and 2) the prevalence of achieving the physical activity guidelines. The majority of participants were female, non-Hispanic black, and almost one-third had a high school education or less. After adjustment, primary transit-use was associated with 134.2 (p < 0.01) additional mean minutes per week of self-reported moderate-intensity transportation-related physical activity compared to non-users. Further, primary users had 7.3 (95% CI: 2.6-20.1) times the relative adjusted odds of meeting physical activity recommendations than non-users based on self-reported transportation-related physical activity. There were no statistically significant associations of transit-use with self-reported leisure-time or accelerometer-derived physical activity. Transit-use has the potential for a large public health impact due to its sustainability and scalability. Therefore, encouraging the use of transit as a means to promote physical activity should be examined in future studies.

Children who commute to school unaccompanied have greater autonomy and perceptions of safety

AIM

We explored the rates of children who actively commuted to school, both accompanied and unaccompanied, and identified their safety perceptions.

METHODS

This cross-sectional study focused on 745 children, aged 6-12 years, from public schools in the Spanish Granada region. They completed a questionnaire, providing personal data, their school grade, safety perceptions, whether they were accompanied to school and how they travelled to school. We analysed how active commuters were accompanied to school by age group and assessed the associations between safety perceptions and whether or not they were accompanied.

RESULTS

Children aged 10-12 years were more likely to travel to school unaccompanied, more likely to travel actively and had better safety perceptions than younger children. We also found differences in how active commuters between 10 and 12 years and children aged 6-7 and 8-9 years (all p < 0.001) were accompanied to school. Children aged 10-12 years who actively commuted unaccompanied had a better understanding of safety issues than accompanied children (p < 0.010).

CONCLUSION

Older children who actively commuted to school unaccompanied had better safety perceptions than other children in this sample of children aged 6-12.

Impact of commuting exposure to traffic-related air pollution on cognitive development in children walking to school

A few studies have found associations between the exposure to traffic-related air pollution at school and/or home and cognitive development. The impact on cognitive development of the exposure to air pollutants during commuting has not been explored. We aimed to assess the role of the exposure to traffic-related air pollutants during walking commute to school on cognitive development of children. We performed a longitudinal study of children (n = 1,234, aged 7-10 y) from 39 schools in Barcelona (Catalonia, Spain) who commuted by foot to school. Children were tested four times during a 12-month follow-up to characterize their developmental trajectories of working memory (d' of the three-back numbers test) and inattentiveness (hit reaction time standard error of the Attention Network Test). Average particulate matter ≤2.5 μm (PM_2.5), Black Carbon (BC) and NO₂ concentrations were estimated using Land Use Regression for the shortest walking route to school. Differences in cognitive growth were evaluated by linear mixed effects models with age-by-pollutant interaction terms. Exposure to PM_2.5 and BC from the commutes by foot was associated with a reduction in the growth of working memory (an interquartile range increase in PM_2.5 and BC concentrations decreased the annual growth of working memory by 5.4 (95% CI [-10.2, -0.6]) and 4.6 (95% CI [-9.0, -0.1]) points, respectively). The findings for NO₂ were not conclusive and none of the pollutants were associated with inattentiveness. Efforts should be made to implement pedestrian school pathways through low traffic streets in order to increase security and minimize children's exposure to air pollutants.

Noise exposure while commuting in Toronto - a study of personal and public transportation in Toronto

Background

With an increasing proportion of the population living in cities, mass transportation has been rapidly expanding to facilitate the demand, yet there is a concern that mass transit has the potential to result in excessive exposure to noise, and subsequently noise-induced hearing loss.

Methods

Noise dosimetry was used to measure time-integrated noise levels in a representative sample of the Toronto Mass Transit system (subway, streetcar, and buses) both aboard moving transit vehicles and on boarding platforms from April – August 2016. 210 measurements were conducted with multiple measurements approximating 2 min on platforms, 4 min within a vehicle in motion, and 10 min while in a car, on a bike or on foot. Descriptive statistics for each type of transportation, and measurement location (platform vs. vehicle) was computed, with measurement locations compared using 1-way analysis of variance.

Results

On average, there are 1.69 million riders per day, who are serviced by 69 subway stations, and 154 streetcar or subway routes. Average noise level was greater in the subway and bus than in the streetcar (79.8 +/− 4.0 dBA, 78.1 +/− 4.9 dBA, vs 71.5 +/−1.8 dBA, p < 0.0001). Furthermore, average noise measured on subway platforms were higher than within vehicles (80.9 +/− 3.9 dBA vs 76.8 +/− 2.6 dBA, p < 0.0001). Peak noise exposures on subway, bus and streetcar routes had an average of 109.8 +/− 4.9 dBA and range of 90.4–123.4 dBA, 112.3 +/− 6.0 dBA and 89.4–128.1 dBA, and 108.6 +/− 8.1 dBA and 103.5–125.2 dBA respectively. Peak noise exposures exceeded 115 dBA on 19.9%, 85.0%, and 20.0% of measurements in the subway, bus and streetcar respectively.

Conclusions

Although the mean average noise levels on the Toronto transit system are within the recommended level of safe noise exposure, cumulative intermittent bursts of impulse noise (peak noise exposures) particularly on bus routes have the potential to place individuals at risk for noise induced hearing loss.

Electronic supplementary material

The online version of this article (10.1186/s40463-017-0239-6) contains supplementary material, which is available to authorized users.

Neighborhood Isolation in Chicago: Violent Crime Effects on Structural Isolation and Homophily in Inter-Neighborhood Commuting Networks, 2002-2013

Urban sociologists and criminologists have long been interested in the link between neighborhood isolation and crime. Yet studies have focused predominantly on the internal dimension of social isolation (i.e., increased social disorganization and insufficient jobs and opportunities). This study highlights the need to assess the external dimension of neighborhood isolation, the disconnectedness from other neighborhoods in the city. Analyses of Chicago's neighborhood commuting network over twelve years (2002-2013) showed that violence predicted network isolation. Moreover, pairwise similarity in neighborhood violence predicted commuting ties, supporting homophily expectations. Violence homophily affected tie formation most, while neighborhood violence was important in dissolving ties.

The relationship between bicycle commuting and perceived stress: a cross-sectional study

INTRODUCTION

Active commuting - walking and bicycling for travel to and/or from work or educational addresses - may facilitate daily, routine physical activity. Several studies have investigated the relationship between active commuting and commuting stress; however, there are no studies examining the relationship between solely bicycle commuting and perceived stress, or studies that account for environmental determinants of bicycle commuting and stress. The current study evaluated the relationship between bicycle commuting, among working or studying adults in a dense urban setting, and perceived stress.

METHODS

A cross-sectional study was performed with 788 adults who regularly travelled to work or study locations (excluding those who only commuted on foot) in Barcelona, Spain. Participants responded to a comprehensive telephone survey concerning their travel behaviour from June 2011 through to May 2012. Participants were categorised as either bicycle commuters or non-bicycle commuters, and (based on the Perceived Stress Scale, PSS-4) as either stressed or non-stressed. Multivariate Poisson regression with robust variance models of stress status based on exposures with bicycle commuting were estimated and adjusted for potential confounders.

RESULTS

Bicycle commuters had significantly lower risk of being stressed than non-bicycle commuters (Relative Risk; RR (95% CI)=0.73 (0.60 to 0.89), p=0.001). Bicycle commuters who bicycled 4 days per week (RR (95% CI)=0.42 (0.24 to 0.73), p=0.002) and those who bicycled 5 or more days per week (RR (95% CI)=0.57 (0.42 to 0.77), p<0.001) had lower risk of being stressed than those who bicycled less than 4 days. This relationship remained statistically significant after adjusting for individual and environmental confounders and when using different cut-offs of perceived stress.

CONCLUSIONS

Stress reduction may be an important consequence of routine bicycle use and should be considered by decision makers as another potential benefit of its promotion.

Evaluation of the implementation of a whole-workplace walking programme using the RE-AIM framework

BACKGROUND

Promoting walking for the journey to/from work and during the working day is one potential approach to increase physical activity in adults. Walking Works was a practice-led, whole-workplace walking programme delivered by employees (walking champions). This study aimed to evaluate the implementation of Walking Works using the RE-AIM framework and provide recommendations for future delivery of whole-workplace walking programmes.

METHODS

Two cross sectional surveys were conducted; 1544 (28%) employees completed the baseline survey and 918 employees (21%) completed the follow-up survey. Effectiveness was assessed using baseline and follow-up data; reach, implementation and maintenance were assessed using follow-up data only. For categorical data, Chi square tests were conducted to assess differences between surveys or groups. Continuous data were analysed to test for significant differences using a Mann-Whitney U test. Telephone interviews were conducted with the lead organisation co-ordinator, eight walking champions and three business representatives at follow-up. Interviews were transcribed verbatim and analysed to identify key themes related to adoption, implementation and maintenance.

RESULTS

Adoption: Five workplaces participated in Walking Works. Reach: 480 (52.3%) employees were aware of activities and 221 (24.1%) participated.

IMPLEMENTATION

A variety of walking activities were delivered. Some programme components were not delivered as planned which was partly due to barriers in using walking champions to deliver activities. These included the walking champions' capacity, skills, support needs, ability to engage senior management, and the number and type of activities they could deliver. Other barriers included lack of management support, difficulties communicating information about activities and challenges embedding the programme into normal business activities. Effectiveness: No significant changes in walking to/from work or walking during the working day were observed. Maintenance: Plans to continue activities were mainly dependent on identifying continued funding.

CONCLUSIONS

RE-AIM provided a useful framework for evaluating Walking Works. No changes in walking behaviour were observed. This may have been due to barriers in using walking champions to deliver activities, programme components not being delivered as intended, the types of activities delivered, or lack of awareness and participation by employees. Recommendations are provided for researchers and practitioners implementing future whole-workplace walking programmes.

Physical activity when riding an electric assisted bicycle

Background

The objectives of the present study were to compare time spent cycling, exercise intensity, and time spent in moderate- (MPA) and vigorous intensity physical activity (VPA) when cycling on an E-bike and a conventional bicycle on two “cycling-to-work” routes with differences in topography, defined as a hilly and a flat route.

Methods

Eight adults (23–54 years, two women) cycled outdoors on a conventional bicycle and an E-bike, on a flat (8.2 km) and a hilly (7.1 km) route, resulting in 32 journeys. Duration, elevation, and oxygen consumption were recorded using a portable oxygen analyser with GPS. A maximal cardiorespiratory fitness test was performed on a cycle ergometer. Resting metabolic rate was obtained by indirect calorimetry with a canopy hood.

Results

The participants spent less time (median (IQR)) cycling on the E-bike compared with the conventional bicycle, on both the hilly (18.8 (4.9) vs. 26.3 (6.4) minutes) and the flat (20.0 (2.9) vs. 23.8 (1.8) minutes) routes. Lower exercise intensity was observed with the E-bike compared with the conventional bicycle, both on the hilly (50 (18) vs. 60 (22) % of maximal oxygen uptake) and the flat (52 (19) vs. 55 (12) % of maximal oxygen uptake) routes. In both cycling modes, most time was spent in MVPA (92–99%). However, fewer minutes were spent in MVPA with the E-bike than the conventional bicycle, for both the hilly (26% lower) and the flat (17% lower) routes. Cycling on the E-bike also resulted in 35 and 15% fewer minutes in vigorous intensity, respectively on the hilly and flat routes.

Conclusion

Cycling on the E-bike resulted in lower trip duration and exercise intensity, compared with the conventional bicycle. However, most of the time was spent in MVPA. This suggests that changing the commuting mode from car to E-bike will significantly increase levels of physical activity while commuting.

How reported usefulness modifies the association between neighborhood supports and walking behavior

Neighborhood supports have been associated with walking, but this association may be modified by reports about the usefulness of these supports for promoting walking. This study examined the association between reported presence of neighborhood supports and walking and whether usefulness modified this association in a nationwide sample of U.S. adults. Measures of reported presence and use or potential use (i.e., usefulness) of neighborhood supports (shops within walking distance, transit stops, sidewalks, parks, interesting things to look at, well-lit at night, low crime rate, and cars following speed limit) were examined in 3973 adults who completed the 2014 SummerStyles survey. Multinomial regression models were used to examine the association between presence of supports with walking frequency (frequently, sometimes, rarely (referent)) and the role usefulness had on this association. The interaction term between reported presence and usefulness was significant for all supports (p<0.05). For adults who reported a support as useful, a positive association between presence of the support and walking frequency was observed for all supports. For adults who did not report a support as useful, the association between presence of the support and walking frequency was null for most supports and negative for sidewalks, well-lit at night, and low crime rate. The association between presence of neighborhood supports and walking is modified by reported usefulness of the support. Tailoring initiatives to meet a community's supply of and affinity for neighborhood supports may help initiatives designed to promote walking and walkable communities succeed.