From targeted "black spots" to area-wide pedestrian safety

Traffic-Calming Measures and Road Traffic Collisions and Injuries: A Spatiotemporal Analysis

Traffic-calming measures (TCMs) are physical modifications of the road network aimed at making the roads safer. Although researchers have reported reductions in numbers of road crashes and injuries tied to the presence of TCMs, such studies have been criticized for their pre-/post- designs. In this study, we aimed to complement our knowledge of TCMs' effectiveness by assessing their impact using a longitudinal design. The implementation of 8 TCMs, including curb extensions and speed humps, was evaluated at the intersection and census tract levels in Montreal, Quebec, Canada, from 2012 to 2019. The primary outcome was fatal or serious collisions among all road users. Inference was performed using a Bayesian implementation of conditional Poisson regression in which random effects were used to account for the spatiotemporal variation in collisions. TCMs were generally implemented on local roads, although most collisions occurred on arterial roads. Overall, there was weak evidence that TCMs were associated with study outcomes. However, subgroup analyses of intersections on local roads suggested a reduction in collision rates due to TCMs (median incidence rate ratio, 0.31; 95% credible interval: 0.12, 0.86). To improve road safety, effective counterparts of TCMs on arterial roads must be identified and implemented.

Citizens’ Perceptions in Relation to Transport Systems and Infrastructures: A Nationwide Study in the Dominican Republic

One of the challenges currently faced by emerging countries is to get their citizens to decide to use sustainable transport for their regular trips, in order to reduce the current vehicular pollution rates. The objective of this descriptive research is to examine the perceptions of Dominicans regarding the state of the country’s transport systems and road infrastructure. For this purpose, a nationwide survey procedure was performed. This cross-sectional research used the data retrieved from a sample of 1260 citizens aged over 18, proportional in gender, age, habitat, and province of the Dominican Republic. The results showed how Dominicans believe that, compared to other road features, pedestrian roads and public transport vehicles remain in a very poor condition. Further, citizens report to be more interested about the improvement of road infrastructures than in the implementation of any other set of measures performed to promote sustainable road mobility, including those related with alternative transport means. Finally, this study claims for the need of fostering educational, communicative and participative actions and measures aimed at increasing the value given to sustainable transportation, and the relevance of integrate potential structural and vehicular improvements with those related to human behavior in mobility.

An investigation of urban pedestrian behaviour in Bangladesh using the Perceptual Cycle Model

In Bangladesh, pedestrians remain the most neglected road user group in terms of research and safety measures, even though they are involved in nearly 50% of all fatal collisions. In the Dhaka metropolitan area, this statistic rises to around 65%. To reduce the recurrence of such collisions, it is necessary to understand the underlying thought processes of pedestrians, and how pedestrians interact with different road users, particularly when crossing the road. This study contributes to knowledge through the analysis of verbal data from 46 pedestrians, framed in terms of the Perceptual Cycle Model, where cognitive processes are described in terms of three categories: schema (mental templates), action (doing things), and world (environmental information). Concurrent verbal reports were provided by participants while they negotiated a busy area of mixed traffic in the centre of Dhaka city. The analysis revealed some of the factors that affected decision-making (for road crossing behaviour) at the different road sections. Many external factors (e.g., street sellers, rubbish blocking the path, lack of shade and poor pavement condition) prevented the pavement from being used and contributed to riskier road crossing behaviour. Some safety implications and related recommendations are presented.

Modelling risk factors for fatal pedestrian crashes in Kolkata, India

In developing countries, pedestrian safety is an issue of major concern. Although an extensive body of literature is available on the identification of elements related to the pedestrian's risk; the studies are primarily conducted in urban areas of developed countries. The findings from these studies may only be partially relevant to the cities of an emerging country such as India. The present study analyzes historical crash records obtained from the "Kolkata Police" and identifies the risk factors at the road network level for the hazardous corridors posing a high risk to the pedestrians. The study findings reveal that pedestrians' fatalities at intersections are associated with a high vehicular volume, higher pedestrian-vehicular interaction, high approach speed, overtaking tendency of vehicles, certain land-use type, encroachment of footpath, inadequate sight distance, inaccessible pedestrian crosswalk, wider minor carriageway, the absence of a pedestrian signal head, and lack of enforcement. On the other hand, the models outcomes reveal that pedestrians' fatalities at midblock road segments are associated with low pedestrian volume, high approach speed, overtaking tendency of the vehicle, encroachment of footpath, on-street parking, wider road width, certain land-use type, inadequate sight distance, insufficient lighting, and inadequate pavement markings.

Spatial Analysis of Curb-Park Violations and Their Relationship with Points of Interest: A Case Study of Tehran, Iran

Car parking is a challenging part of urban transportation and traffic violations cause many problems for citizens. Studies have shown that there is a direct relationship between vehicle parking violations and urban places. In this study, we investigated the spatial distribution of vehicle violations in a region of Tehran, Iran, that is suffering from a heavy traffic load and heavily polluted air. Although there are two dissimilar urban segregations in the north and south of the study area, in both of the regions, about 70% of all curb-parks are legal, while the remaining are illegal. However, our analysis indicates a dissimilar pattern of car parking violations. Additionally, spatial analysis reveals a direct relationship between some POIs (Point of interests) and the occurrence of car park violations. For example, the number of vehicle park violations around the hospitals is more than the average of the study area. However, the number of park violations around the universities is less than the average. Our results also show that POIs have an impact radius that leads to violations occurring in that area. For example, the influence range of a hospital on the creation of car park violations was estimated at 125 meters. Our presented approach along with the discussed findings and conclusions can be useful to an extensive range of stakeholders, including urban planners, traffic police departments, local municipalities, law enforcement agencies and environmentalists, to have a better perspective of infrastructure planning.

A comparative study of safe and unsafe signalized intersections from the view point of pedestrian behavior and perception

Signalized intersections with marked crosswalks enhance pedestrian safety by providing the designated right of way to pedestrians. However, a significant number of pedestrian fatalities occur at signalized intersections, which may primarily be due to pedestrians' violation behaviors. Since pedestrians' fatalities are not uniform across signalized intersections in a city, it may be expected that violations would also vary across the sites. It is thus worthwhile to investigate if the pedestrian signal violation is a good surrogate for fatal pedestrian crashes at signalized intersections, and if so, what behavioral, spatial, and built environment related factors influence such violations. To this end, present study analyzes pedestrian behavior and perceptions across twenty-four signalized intersections in Kolkata city, India, out of which twelve intersections did not record any fatal pedestrian crashes between 2011 and 2016 and the remaining twelve experienced at least three or more fatal pedestrian crashes over the same period. Using data from the video-graphic survey at these twenty-four signalized intersections violation behaviors are extracted along with personal attributes at the pedestrian level. Further, pedestrian perception surveys are carried out at each of the twenty-four sites, to obtain a user's perception of safety and satisfaction. Results indicate that pedestrians' signal violations behavior and dissatisfaction are statistically significantly higher at locations with recorded fatal pedestrian crashes. Results from different models and analysis clearly pointed out several planning and design deficiencies such as longer waiting time before crossing, higher pedestrian-vehicular interaction, pedestrian's state of crossing, and a number of personal level attributes such as pedestrian's intended mode of transportation and their state of journey, pedestrian's home location, pedestrian's socio-demographic characteristics as important predictors of pedestrians' violation behavior. The methodology and findings are useful not only for proactive safety improvement at signalized intersections but also to proactively identify potential unsafe sites.

Development of pedestrian crash prediction model for a developing country using artificial neural network

Urban intersections in India constitute a significant share of pedestrian fatalities. However, model-based prediction of pedestrian fatalities is still in a nascent stage in India. This study proposes an artificial neural network (ANN) technique to develop a pedestrian fatal crash frequency model at the intersection level. In this study, three activation functions are used along with four different learning algorithms to build different combinations of ANN models. In each of these combinations, the number of neurons in the hidden layer is varied by trial and error method, and the best results are considered. In this way, 12 sets of pedestrian fatal crash predictive models are developed. Out of these, Bayesian Regularization Neural Network consisting of 13 neurons in the hidden layer with 'hyperbolic tangent-sigmoid' activation function is found to be the best-fit model. Finally, based on sensitivity analysis, it is found that the 'approaching speed' of the motorized vehicle has the most significant influence on the fatal pedestrian crashes. 'Logarithm of average daily traffic' (ADT) volume is found to be the second most sensitive variable. Pedestrian-vehicular interaction concerning 'pedestrian-vehicular volume ratio' and lack of 'accessibility of pedestrian cross-walk' are found to be approximately as sensible as 'logarithm of ADT'.

Bayesian approach to model pedestrian crashes at signalized intersections with measurement errors in exposure

This study intended to identify the potential factors contributing to the occurrence of pedestrian crashes at signalized intersections in a densely populated city, based on a comprehensive dataset of 898 pedestrian crashes at 262 signalized intersections during 2010-2012 in Hong Kong. The detailed geometric design, traffic characteristics, signal control, built environment, along with the vehicle and pedestrian volumes were elaborately collected. A Bayesian measurement errors model was introduced as an alternative method to explicitly account for the uncertainties in volume data. To highlight the role played by exposure, models with and without pedestrian volume were estimated and compared. The results indicated that the omission of pedestrian volume in pedestrian crash frequency models would lead to reduced goodness-of-fit, biased parameter estimates, and incorrect inferences. Our empirical analysis demonstrated the existence of moderate uncertainties in pedestrian and vehicle volumes. Six variables were found to have a significant association with the number of pedestrian crashes at signalized intersections. The number of crossing pedestrians, the number of passing vehicles, the presence of curb parking, and the presence of ground-floor shops were positively related with pedestrian crash frequency, whereas the presence of playgrounds near intersections had a negative effect on pedestrian crash occurrences. Specifically, the presence of exclusive pedestrian signals for all crosswalks was found to significantly reduce the risk of pedestrian crashes by 43%. The present study is expected to shed more light on a deeper understanding of the environmental determinants of pedestrian crashes.

National 10-year trend in road injuries involving school children on the way to and from school in Japan, 2003-2012

OBJECTIVES

To quantitatively describe the recent longitudinal trend in road injuries involving school children while commuting to and from school in Japan and to identify groups or situations with particularly large or small decreasing trends.

METHODS

Data on the number of children aged 6-15 years who sustained road injuries while commuting were obtained, stratified by year, demographic characteristics, mode of transport and other variables. The rates of killed or seriously injured (KSI) children were calculated from the number of KSI cases (the numerator) and the product of population and the proportion of each mode of transport estimated using the Person Trip Survey data (the denominator). We conducted descriptive analyses of the longitudinal trend in KSI rates stratified by the variables, and Poisson regression analyses were employed to quantify the annualised changes in the rates.

RESULTS

During the study period, 166 children were killed and 8484 children were seriously injured; the KSI rate decreased approximately 30%. The KSI rate was almost 10 times higher among cyclists than pedestrians. In cyclists, the decrease in the KSI rate among children aged 12-15 years was smaller in boys than in girls (estimated change -14% vs -30%). The KSI rate of male pedestrians aged 6-7 years was larger than female and older pedestrians, with a large decrease of 48%.

CONCLUSIONS

Although the overall rate of road injuries among children while commuting was decreasing, cyclists were at a much greater risk than pedestrians, and the improvements for cyclists occurred at a slower pace.

An overview of geospatial methods used in unintentional injury epidemiology

Background

Injuries are a leading cause of death and disability around the world. Injury incidence is often associated with socio-economic and physical environmental factors. The application of geospatial methods has been recognised as important to gain greater understanding of the complex nature of injury and the associated diverse range of geographically-diverse risk factors. Therefore, the aim of this paper is to provide an overview of geospatial methods applied in unintentional injury epidemiological studies.

Methods

Nine electronic databases were searched for papers published in 2000–2015, inclusive. Included were papers reporting unintentional injuries using geospatial methods for one or more categories of spatial epidemiological methods (mapping; clustering/cluster detection; and ecological analysis). Results describe the included injury cause categories, types of data and details relating to the applied geospatial methods.

Results

From over 6,000 articles, 67 studies met all inclusion criteria. The major categories of injury data reported with geospatial methods were road traffic (n = 36), falls (n = 11), burns (n = 9), drowning (n = 4), and others (n = 7). Grouped by categories, mapping was the most frequently used method, with 62 (93%) studies applying this approach independently or in conjunction with other geospatial methods. Clustering/cluster detection methods were less common, applied in 27 (40%) studies. Three studies (4%) applied spatial regression methods (one study using a conditional autoregressive model and two studies using geographically weighted regression) to examine the relationship between injury incidence (drowning, road deaths) with aggregated data in relation to explanatory factors (socio-economic and environmental).

Conclusion

The number of studies using geospatial methods to investigate unintentional injuries has increased over recent years. While the majority of studies have focused on road traffic injuries, other injury cause categories, particularly falls and burns, have also demonstrated the application of these methods. Geospatial investigations of injury have largely been limited to mapping of data to visualise spatial structures. Use of more sophisticated approaches will help to understand a broader range of spatial risk factors, which remain under-explored when using traditional epidemiological approaches.

Electronic supplementary material

The online version of this article (doi:10.1186/s40621-016-0097-0) contains supplementary material, which is available to authorized users.

Multilevel models for evaluating the risk of pedestrian-motor vehicle collisions at intersections and mid-blocks

Walking is a popular form of physical activity associated with clear health benefits. Promoting safe walking for pedestrians requires evaluating the risk of pedestrian-motor vehicle collisions at specific roadway locations in order to identify where road improvements and other interventions may be needed. The objective of this analysis was to estimate the risk of pedestrian collisions at intersections and mid-blocks in Seattle, WA. The study used 2007-2013 pedestrian-motor vehicle collision data from police reports and detailed characteristics of the microenvironment and macroenvironment at intersection and mid-block locations. The primary outcome was the number of pedestrian-motor vehicle collisions over time at each location (incident rate ratio [IRR] and 95% confidence interval [95% CI]). Multilevel mixed effects Poisson models accounted for correlation within and between locations and census blocks over time. Analysis accounted for pedestrian and vehicle activity (e.g., residential density and road classification). In the final multivariable model, intersections with 4 segments or 5 or more segments had higher pedestrian collision rates compared to mid-blocks. Non-residential roads had significantly higher rates than residential roads, with principal arterials having the highest collision rate. The pedestrian collision rate was higher by 9% per 10 feet of street width. Locations with traffic signals had twice the collision rate of locations without a signal and those with marked crosswalks also had a higher rate. Locations with a marked crosswalk also had higher risk of collision. Locations with a one-way road or those with signs encouraging motorists to cede the right-of-way to pedestrians had fewer pedestrian collisions. Collision rates were higher in locations that encourage greater pedestrian activity (more bus use, more fast food restaurants, higher employment, residential, and population densities). Locations with higher intersection density had a lower rate of collisions as did those in areas with higher residential property values. The novel spatiotemporal approach used that integrates road/crossing characteristics with surrounding neighborhood characteristics should help city agencies better identify high-risk locations for further study and analysis. Improving roads and making them safer for pedestrians achieves the public health goals of reducing pedestrian collisions and promoting physical activity.

Major urban road characteristics and injured pedestrians: A representative survey of intersections in Montréal, Quebec

OBJECTIVES

In urban settings, pedestrian fatalities and injuries are concentrated on major roads. This study aims to describe urban intersections with major roads (arterials and collector roads) and explore the association between intersection characteristics and injured pedestrians.

METHODS

From a stratified random sampling in Montréal, Quebec, 512 intersections were selected and their characteristics collected. The number of injured pedestrians from 1999 to 2008 was obtained from ambulance services. Binomial negative regression models (including IRR: incidence rate ratios) were calculated to determine associations between intersection characteristics and injured pedestrians: i) at all intersections; ii) at intersections with multi-lane roads and iii) at signalized intersections with available vehicle and pedestrian counts.

RESULTS

Major intersections had more traffic lanes (3.8 vs. 1.7, p < 0.01) and longer pedestrian crossings (18.8 m vs. 12.7 m, p < 0.01) than minor intersections. Bus stops were also more frequent at these intersections (75% vs. 6%, p < 0.01). Overall, each additional traffic lane was associated with a 75% increase in the number of injured pedestrians (IRR = 1.75; 95% confidence interval [CI] = 1.41-2.18). At intersections with multi-lane roads, a fourth branch (IRR = 2.40; 95% CI = 1.53-3.77), vehicles parked within 5 m of the intersection (IRR = 2.40; 95% CI = 1.64-3.51), and marked crosswalks (IRR = 1.79; 95% CI = 1.08-2.95) significantly increased the number of injured pedestrians. Raised medians had no significant protective effect.

CONCLUSIONS

The results show that besides traffic and pedestrian volumes, intersection characteristics contribute to pedestrian injuries. The reduction of traffic lanes, parking prohibition near intersections and implementation of appropriate pedestrian refuge areas would improve pedestrian safety.

Multimodal injury risk analysis of road users at signalized and non-signalized intersections

This paper proposes a multimodal approach to study safety at intersections by simultaneously analysing the safety and flow outcomes for both motorized and non-motorized traffic. This study uses an extensive inventory of signalized and non-signalized intersections on the island of Montreal, Quebec, Canada, containing disaggregate motor-vehicle, cyclist and pedestrian flows, injury data, geometric design, traffic control and built environment characteristics in the vicinity of each intersection. Bayesian multivariate Poisson models are used to analyze the injury and traffic flow outcomes and to develop safety performance functions for each mode at both facilities. After model calibration, contributing injury frequency factors are identified. Injury frequency and injury risk measures are then generated to carry out a comparative study to identify which mode is at greatest risk at intersections in Montreal. Among other results, this study identified the significant effect that motor-vehicle traffic imposes on cyclist and pedestrian injury occurrence. Motor-vehicle traffic is the main risk determinant for all injury and intersection types. This highlights the need for safety improvements for cyclists and pedestrians who are, on average, at 14 and12 times greater risk than motorists, respectively, at signalized intersections. Aside from exposure measures, this work also identifies some geometric design and built environment characteristics affecting injury occurrence for cyclists, pedestrians and motor-vehicle occupants.

GEOGRAPIC INFORMATION SYSTEMS IN DETERMINING ROAD TRAFFIC CRASH ANALYSIS IN IBADAN, NIGERIA

BACKGROUND

Road traffic accidents are frequent in this environment, hence the need to determine the place of geographic information systems in the documentation of road traffic accidents.

AIM & OBJECTIVES

To investigate and document the variations in crash frequencies by types and across different road types in Ibadan, Nigeria.

MATERIALS & METHODS

Road traffic accident data between January and June 2011 were obtained from the University College Hospital Emergency Department's trauma registry. All the traffic accidents were categorized into motor vehicular, motorbike and pedestrian crashes. Georeferencing of accident locations mentioned by patients was done using a combination of Google Earth and ArcGIS software. Nearest neighbor statistic, Moran's-I, Getis-Ord statistics, Student T-test, and ANOVA were used in investigating the spatial dynamics in crashes.

RESULTS

Out of 600 locations recorded, 492 (82.0%) locations were correctly georeferenced. Crashes were clustered in space with motorbike crashes showing greatest clustering. There was significant difference in crashes between dual and non-dual carriage roads (P = 0.0001), but none between the inner city and the periphery (p = 0.115). However, significant variations also exist among the three categories analyzed (p = 0.004) and across the eleven Local Government Areas (P = 0.017).

CONCLUSION

This study showed that the use of Geographic Information System can help in understanding variations in road traffic accident occurrence, while at the same time identifying locations and neighborhoods with unusually higher accidents frequency.

A Poisson-lognormal conditional-autoregressive model for multivariate spatial analysis of pedestrian crash counts across neighborhoods

This work examines the relationship between 3-year pedestrian crash counts across Census tracts in Austin, Texas, and various land use, network, and demographic attributes, such as land use balance, residents' access to commercial land uses, sidewalk density, lane-mile densities (by roadway class), and population and employment densities (by type). The model specification allows for region-specific heterogeneity, correlation across response types, and spatial autocorrelation via a Poisson-based multivariate conditional auto-regressive (CAR) framework and is estimated using Bayesian Markov chain Monte Carlo methods. Least-squares regression estimates of walk-miles traveled per zone serve as the exposure measure. Here, the Poisson-lognormal multivariate CAR model outperforms an aspatial Poisson-lognormal multivariate model and a spatial model (without cross-severity correlation), both in terms of fit and inference. Positive spatial autocorrelation emerges across neighborhoods, as expected (due to latent heterogeneity or missing variables that trend in space, resulting in spatial clustering of crash counts). In comparison, the positive aspatial, bivariate cross correlation of severe (fatal or incapacitating) and non-severe crash rates reflects latent covariates that have impacts across severity levels but are more local in nature (such as lighting conditions and local sight obstructions), along with spatially lagged cross correlation. Results also suggest greater mixing of residences and commercial land uses is associated with higher pedestrian crash risk across different severity levels, ceteris paribus, presumably since such access produces more potential conflicts between pedestrian and vehicle movements. Interestingly, network densities show variable effects, and sidewalk provision is associated with lower severe-crash rates.

A population approach to transportation planning: reducing exposure to motor-vehicles

Transportation planning and public health have important historical roots. To address common challenges, including road traffic fatalities, integration of theories and methods from both disciplines is required. This paper presents an overview of Geoffrey Rose's strategy of preventive medicine applied to road traffic fatalities. One of the basic principles of Rose's strategy is that a large number of people exposed to a small risk can generate more cases than a small number exposed to a high risk. Thus, interventions should address the large number of people exposed to the fundamental causes of diseases. Exposure to moving vehicles could be considered a fundamental cause of road traffic deaths and injuries. A global reduction in the amount of kilometers driven would result in a reduction of the likelihood of collisions for all road users. Public health and transportation research must critically appraise their practice and engage in informed dialogue with the objective of improving mobility and productivity while simultaneously reducing the public health burden of road deaths and injuries.

The potential modal shift and health benefits of implementing a public bicycle share program in Montreal, Canada

BACKGROUND

This study estimated the modal shift associated with the implementation of a public bicycle share program in Montreal, Canada.

METHODS

A population-based sample of adults participated in two cross sectional telephone surveys. Self-reported travel behaviors were collected at the end of the first (fall 2009) and second (fall 2010) season of implementation. The sample included 2502 (Mean age=47.8 years, 61.8% female), and 2509 (Mean age=48.9 years, 59.0% female) adult respondents in each survey.

RESULTS

The estimated modal shift associated with the implementation of the PBSP from motor vehicle use to walking, cycling, and public transportation was 6483 and 8023 trips in 2009 and 2010. This change represents 0.34% and 0.43% of all motor vehicle trips in Montreal.

CONCLUSIONS

The implementation of a PBSP was associated with a shift toward active transportation. The modal shift was complex and not simply the result of a discrete shift from one mode to another. Promotion of active transportation should encourage integration of multiple active transportation modes to better reflect people's actual transportation behaviors.

Methodological proposal for implementing an intervention to prevent pedestrian injuries, a multidisciplinary approach: the case of Cuernavaca, Morelos, Mexico

OBJECTIVE

To describe the process for implementing an intervention to prevent pedestrian injuries in Cuernavaca, Mexico, using a multidisciplinary and evidence-based approach.

METHODOLOGY

This study included two phases with several stages. The first was an overall assessment of pedestrian mortality in Cuernavaca that included a comparison of pedestrian mortality between Cuernavaca and the rest of Morelos State (1998-2007), an analysis and geocoding of pedestrian injuries (2008-2009), and a description of techniques for selecting and analysing clustered events using road audits. The second phase focused on selecting an intervention through a review of the literature seeking the 'best evidence' adaptable to the local context and a methodological evaluation for implementation including techniques for cluster randomisation and for the evaluation of possible effects of the intervention.

RESULTS

Between 2008 and 2009, in Cuernavaca there were 620 pedestrian injury events: 59.4% were men, the mean age was 36.3 years, 70% occurred during daylight hours, 55% had mild severity and there were no differences by sex (p>0.05). We generated evidence, that when combined with the results from a systematic search of the literature, provided sufficient information for the implementation of a pedestrian injury prevention intervention.

CONCLUSIONS

A combination of strategies and disciplines makes it possible to comprehensively address this public health problem, allowing interventions to strengthen aspects of pedestrian safety while accounting for characteristics of the local context; the promotion of local measures, of low cost and high impact, with modifications to the road infrastructure, are more effective in addressing pedestrian vulnerabilities.

Outdoor falls in an urban context: winter weather impacts and geographical variations

OBJECTIVES

Environmental factors associated with winter outdoor falls are poorly understood. This study describes the demographic, spatial and temporal distribution of outdoor falls that occurred in Laval and Montréal Island (Canada) in relation to meteorological conditions.

METHOD

Data on falls, including geographic coordinates, were obtained from ambulance services (December 1, 2008 to january 31, 2009). Meteorological (temperature, precipitation levels) and land use data were used for descriptive analysis and mapping.

RESULTS

During the study period, 3270 falls required ambulance interventions, of which 960 occurred outdoors. Most people injured outdoors were under 65 years of age (59%). Mapping showed a concentration of outdoor falls in central neighbourhoods and on commercial streets in Montreal. Three episodes of excess falls, representing 47% of all outdoor falls, were preceded by rain and followed by falling temperatures, or were concomitant with freezing rain.

CONCLUSION

Our results demonstrate for the first time the distribution of outdoor falls in a densely populated urban setting with a northern climate. To promote active transportation, it is essential to take into account the safety of pedestrian travel. Snow removal and de-icing operations in municipalities should prioritize areas with high pedestrian activity.

Neighborhood social inequalities in road traffic injuries: the influence of traffic volume and road design

OBJECTIVES

We examined the extent to which differential traffic volume and road geometry can explain social inequalities in pedestrian, cyclist, and motor vehicle occupant injuries across wealthy and poor urban areas.

METHODS

We performed a multilevel observational study of all road users injured over 5 years (n=19,568) at intersections (n=17,498) in a large urban area (Island of Montreal, Canada). We considered intersection-level (traffic estimates, major roads, number of legs) and area-level (population density, commuting travel modes, household income) characteristics in multilevel Poisson regressions that nested intersections in 506 census tracts.

RESULTS

There were significantly more injured pedestrians, cyclists, and motor vehicle occupants at intersections in the poorest than in the richest areas. Controlling for traffic volume, intersection geometry, and pedestrian and cyclist volumes greatly attenuated the event rate ratios between intersections in the poorest and richest areas for injured pedestrians (-70%), cyclists (-44%), and motor vehicle occupants (-44%).

CONCLUSIONS

Roadway environment can explain a substantial portion of the excess rate of road traffic injuries in the poorest urban areas.

The link between built environment, pedestrian activity and pedestrian-vehicle collision occurrence at signalized intersections

This paper studies the influence of built environment (BE) - including land use types, road network connectivity, transit supply and demographic characteristics - on pedestrian activity and pedestrian-vehicle collision occurrence. For this purpose, a two-equation modeling framework is proposed to investigate the effect of built environment on both pedestrian activity and vehicle-pedestrian collision frequency at signalized intersections. Using accident data of ambulance services in the City of Montreal, the applicability of our framework is illustrated. Different model settings were attempted as part of a model sensitivity analysis. Among other results, it was found that the BE in the proximity of an intersection has a powerful association with pedestrian activity but a small direct effect on pedestrian-vehicle collision frequency. This suggests that the impact of BE is mainly mediated through pedestrian activity. In other words, strategies that encourage densification, mix of land uses and increase in transit supply will increase pedestrian activity and may indirectly, with no supplementary safety strategies, increase the total number of injured pedestrians. In accordance with previous research, the number of motor vehicles entering a particular intersection is the main determinant of collision frequency. Our results show that a 30% reduction in the traffic volume would reduce the total number of injured pedestrians by 35% and the average risk of pedestrian collision by 50% at the intersections under analysis. Major arterials are found to have a double negative effect on pedestrian safety. They are positively linked to traffic but negatively associated with pedestrian activity. The proposed framework is useful for the identification of effective pedestrian safety actions, the prediction of pedestrian volumes and the appropriate safety design of new urban developments that encourage walking.

Risk of injury for bicycling on cycle tracks versus in the street

Most individuals prefer bicycling separated from motor traffic. However, cycle tracks (physically separated bicycle-exclusive paths along roads, as found in The Netherlands) are discouraged in the USA by engineering guidance that suggests that facilities such as cycle tracks are more dangerous than the street. The objective of this study conducted in Montreal (with a longstanding network of cycle tracks) was to compare bicyclist injury rates on cycle tracks versus in the street. For six cycle tracks and comparable reference streets, vehicle/bicycle crashes and health record injury counts were obtained and use counts conducted. The relative risk (RR) of injury on cycle tracks, compared with reference streets, was determined. Overall, 2.5 times as many cyclists rode on cycle tracks compared with reference streets and there were 8.5 injuries and 10.5 crashes per million bicycle-kilometres. The RR of injury on cycle tracks was 0.72 (95% CI 0.60 to 0.85) compared with bicycling in reference streets. These data suggest that the injury risk of bicycling on cycle tracks is less than bicycling in streets. The construction of cycle tracks should not be discouraged.

Analyzing the effects of place on injury: Does the choice of geographic scale and zone matter?

BACKGROUND

Recent studies have shown that the morbidity and mortality associated with injury of pedestrians are inversely related to socio-economic status (SES). However, in drawing inferences from this association, investigators have paid little attention to the modifiable artifacts related to scale and how the data are partitioned. The purpose of this population-based study was to identify the relation between SES and incidence patterns of pedestrian injury at 4 different geographic scales.

METHODS

We used a Poisson generalized linear model, stratified by age and sex, to analyze the relation between each of 4 area measures of SES and incidence patterns of pedestrian injuries occurring in metropolitan Vancouver between 1 January 2001 and 31 March 2006. The 4 area measures of SES were based on boundaries of dissemination areas, census tracts, custom-defined census tracts (generated by reassignment of dissemination area boundaries by means of a geographic information system) and census subdivisions of the Canadian census. We measured the SES of the location where the injury occurred with the Vancouver Area Neighbourhood Deprivation Index.

RESULTS

A total of 262 injuries in adults (18 years of age or older) were analyzed. Among adult men, the odds ratio (OR) for injury of pedestrians at the scale of dissemination area was 4.93 (95% confidence interval [CI] 2.89-8.42) for areas having the lowest SES relative to those with the highest SES. For the same population, the OR for injury was lower with increasing aggregation of data: 2.33 (95% CI 1.45-3.74) when census tracts were used, 3.26 (95% CI 2.06-5.16) when modified census tracts were used and 1.27 (95% CI 0.47-3.45) when census subdivisions were used. Among adult women, the OR for pedestrian injury by SES was highest at the scale of census subdivision within medium-low SES areas (4.33, 95% CI 1.23-15.22). At the census subdivision scale, the relation between SES and incidence pattern of injury was not consistent with findings at smaller geographic scales, and the OR for injury decreased with each increase in SES.

INTERPRETATION

In this analysis, there was significant variability when different administrative boundaries were applied as proxy measures of the effects of place on incidence patterns of injury. The hypothesized influence of SES on prevalence of pedestrian injury followed a statistically significant socio-economic gradient when analyzed using small-area boundaries of the census. However, researchers should be aware of the inherent variability that remains even among the more homogenous population units.

The impact of built environment on pedestrian crashes and the identification of crash clusters on an urban university campus

OBJECTIVES

Motor vehicle-pedestrian crash is a significant public health concern. The urban campus of Georgia State University poses unique challenges due to a large number of students and university employees. The objectives of this study are twofold: 1) to examine the correlation between specific features of the built environment on and around the University campus and pedestrian crashes; and 2) to identify crash clusters in the study area using network-based geospatial techniques.

METHODS

We obtained pedestrian crash data (n=119) from 2003 to 2007 from Georgia Department of Transportation and evaluated environmental features pertaining to the road infrastructure, pedestrian infrastructure and streetscape for each road segment and intersection. Prevalence rate of each feature with pedestrian crashes present was calculated. We used network-based Kernel Density Estimation to identify the high density road segments and intersections, then used network-based K-function to examine the clustering of pedestrian crashes.

RESULTS

Over 50% of the crosswalk signs, pedestrian signals, public transit, and location branding signs (more than three) at intersections involved pedestrian crashes. More than half of wider streets (greater than 29 feet), two-way streets, and streets in good condition had pedestrian crashes present. Crashes occurred more frequently in road segments with strong street compactness and mixed land use present and were significantly (p<0.05) clustered in these high-density zones.

CONCLUSION

Findings can be used to understand the correlation between built environment and pedestrian safety, to prioritize the high-density zones for intervention efforts, and to formulate research hypotheses for investigating pedestrian crashes.

GIS and injury prevention and control: history, challenges, and opportunities

Intentional and unintentional injury is the leading cause of death and potential years of life lost in the first four decades of life in industrialized countries around the world. Despite surgical innovations and improved access to emergency care, research has shown that certain populations remain particularly vulnerable to the risks and consequences of injury. Recent evidence has shown that the analytical, data linkage, and mapping tools of geographic information systems (GIS) technology provide can further address these determinants and identify populations in need. This paper traces the history of injury prevention and discusses current and future challenges in furthering our understanding of the determinants of injury through the use of GIS.

Pedestrian injury and the built environment: an environmental scan of hotspots

Background

Pedestrian injury frequently results in devastating and costly injuries and accounts for 11% of all road user fatalities. In the United States in 2006 there were 4,784 fatalities and 61,000 injuries from pedestrian injury, and in 2007 there were 4,654 fatalities and 70,000 injuries. In Canada, injury is the leading cause of death for those under 45 years of age and the fourth most common cause of death for all ages Traumatic pedestrian injury results in nearly 4000 hospitalizations in Canada annually. These injuries result from the interplay of modifiable environmental factors. The objective of this study was to determine links between the built environment and pedestrian injury hotspots in Vancouver.

Methods

Data were obtained from the Insurance Corporation of British Columbia (ICBC) for the 6 year period from 2000 to 2005 and combined with pedestrian injury data extracted from the British Columbia Trauma Registry (BCTR) for the same period. High incident locations (hotspots) for pedestrian injury in the City of Vancouver were identified and mapped using geographic information systems (GIS), and the characteristics of the built environment at each of the hotspot locations were examined by a team of researchers.

Results

The analysis highlighted 32 pedestrian injury hotspot locations in Vancouver. 31 of 32 hotspots were situated on major roads. Likewise, the majority of hotspots were located on downtown streets. The 'downtown eastside' was identified as an area with multiple high-incident locations, including the 2 highest ranked pedestrian injury hotspots. Bars were present at 21 of the hotspot locations, with 11 of these locations being judged to have high alcohol establishment density.

Conclusion

This study highlighted the disproportionate burden of pedestrian injury centred on the downtown eastside area of Vancouver. The environmental scan revealed that important passive pedestrian safety countermeasures were only present at a minority of high-incident locations. More importantly, bars were highly associated with risk of pedestrian injury. This study is the basis for potential public health intervention by clearly indicating optimal locations for signalized pedestrian crosswalks.

An area-level model of vehicle-pedestrian injury collisions with implications for land use and transportation planning

There is growing awareness among urban planning, public health, and transportation professionals that design decisions and investments that promote walking can be beneficial for human and ecological health. Planners need practical tools to consider the impact of development on pedestrian safety, a key requirement for the promotion of walking. Simple bivariate models have been used to predict changes in vehicle-pedestrian injury collisions based on changes in traffic volume. We describe the development of a multivariate, area-level regression model of vehicle-pedestrian injury collisions based on environmental and population data in 176 San Francisco, California census tracts. Predictor variables examined included street, land use, and population characteristics, including commute behaviors. The final model explained approximately 72% of the systematic variation in census-tract vehicle-pedestrian injury collisions and included measures of traffic volume, arterial streets without transit, land area, proportion of land area zoned for neighborhood commercial and residential-neighborhood commercial uses, employee and resident populations, proportion of people living in poverty and proportion aged 65 and older. We have begun to apply this model to predict area-level change in vehicle-pedestrian injury collisions associated with land use development and transportation planning decisions.

Comparison of Poisson and Bernoulli spatial cluster analyses of pediatric injuries in a fire district

Background

With limited resources available, injury prevention efforts need to be targeted both geographically and to specific populations. As part of a pediatric injury prevention project, data was obtained on all pediatric medical and injury incidents in a fire district to evaluate geographical clustering of pediatric injuries. This will be the first step in attempting to prevent these injuries with specific interventions depending on locations and mechanisms.

Results

There were a total of 4803 incidents involving patients less than 15 years of age that the fire district responded to during 2001–2005 of which 1997 were categorized as injuries and 2806 as medical calls. The two cohorts (injured versus medical) differed in age distribution (7.7 ± 4.4 years versus 5.4 ± 4.8 years, p < 0.001) and location type of incident (school or church 12% versus 15%, multifamily residence 22% versus 13%, single family residence 51% versus 28%, sport, park or recreational facility 3% versus 8%, public building 8% versus 7%, and street or road 3% versus 30%, respectively, p < 0.001). Using the medical incident locations as controls, there was no significant clustering for environmental or assault injuries using the Bernoulli method while there were four significant clusters for all injury mechanisms combined, 13 clusters for motor vehicle collisions, one for falls, and two for pedestrian or bicycle injuries. Using the Poisson cluster method on incidence rates by census tract identified four clusters for all injuries, three for motor vehicle collisions, four for fall injuries, and one each for environmental and assault injuries. The two detection methods shared a minority of overlapping geographical clusters.

Conclusion

Significant clustering occurs overall for all injury mechanisms combined and for each mechanism depending on the cluster detection method used. There was some overlap in geographic clusters identified by both methods. The Bernoulli method allows more focused cluster mapping and evaluation since it directly uses location data. Once clusters are found, interventions can be targeted to specific geographic locations, location types, ages of victims, and mechanisms of injury.