Turning at intersections and pedestrian injuries

Injury patterns in motor vehicle collision-pediatric pedestrian deaths

OBJECTIVE

To describe fatal pediatric pedestrian injury patterns and correlate them with motor vehicle collision (MVC) characteristics and pedestrian kinematics using data from medicolegal death investigations of MVCs occurring in the current Canadian MV fleet and determine the applicability of the classical "Waddell's triad" comprising knee, hip (femur) or pelvis and craniocerebral injuries to present data injury patterns.

METHODS

An Injury Data Collection Form was used to extract MV, MVC, pedestrian demographic and injury information from the Office of the Chief Coroner for Ontario database using autopsy data from 2013 to 2018. Injuries were coded using the Abbreviated Injury Scale (AIS) 2015 revision. The study focused on AIS ≥3 injuries utilizing the Maximum Abbreviated Injury Scale (MAIS), MAIS by Body Region (MAISBR) and Injury Severity Score (ISS).

RESULTS

Between 2013 and 2018, there were 25 pediatric deaths. The pedestrians were either struck and run over (n = 17, 68%; 56% low speed) or struck and projected (n = 8, 32%). Twenty-two deaths were from frontal impacts; three were from reversing vehicles. Fourteen of the 17 (82.4%) run over cases occurred at low speed (<30 km/h). In 9 (36%) cases, the vehicle was turning at impact (right n = 3, left n = 6). A majority of the vehicles had a high hood edge. The head was the most severely injured (median MAISBR = 5 overall and ≤10 years; median MAISBR = 6 for 11-14 years old) followed by the neck (MAISBR = 3 overall; 6-14 years old), and the thorax (median MAISBR = 3 overall; all age groups). For the early adolescents (11-14 years old), the serious injury pattern included the abdomen (median MAISBR = 3.5). Nearly half (n = 11, 44%) sustained brainstem injuries. Over fifty percent of the 16 cases with neck injuries (n = 9, 56.3%) had atlanto-occipital or axial dislocation.

CONCLUSION

More than half of the deaths occurred during low speed run overs. MAIS ≥3 injuries trended to a dyad of head and thorax in ≤5 years old, a triad of head, neck, and thorax injuries in children 6-10 years old and a tetrad with the addition of abdominal injuries in pedestrians ≥11 years old. Waddell's triad was not applicable to the fatal cases in the present study.

The effects of left-turn traffic-calming treatments on conflicts and speeds in Washington, DC

INTRODUCTION

Left-turning vehicles pose considerable safety risks to pedestrians at intersections. Left-turn traffic-calming treatments are designed to slow left-turn traffic. This study examined the effects of one type of left-turn calming, the hardened-centerline treatment, on the numbers of conflicts between left-turning vehicles and pedestrians and left-turn speeds in Washington, DC.

METHOD

Numbers of conflicts between left-turning vehicles and pedestrians, as well as left-turn speeds, were collected at selected intersections in Washington, DC, where the hardened centerline was installed, as well as at control intersections in the city where no treatment was installed, before and after installation. Poisson regression evaluated the change in numbers of conflicts associated with the hardened-centerline treatment. The effect of the treatment on left-turn speeds was estimated by a log-linear regression model, and the effect on the odds of left-turning vehicles exceeding 15 mph was estimated by a logistic regression model.

RESULTS

The treatment was associated with a 70.5% reduction in conflicts between left-turning vehicles and pedestrians, a 9.8% reduction in mean left-turn speeds, and a 67.1% reduction in the odds of left-turning vehicles exceeding 15 mph. All the reductions were statistically significant.

CONCLUSIONS

The study demonstrates that the hardened-centerline treatment can reduce conflicts between left-turning vehicles and pedestrians, and slow down left-turn traffic at intersections. Practical applications: The treatment should be added to the toolbox for communities looking to improve pedestrian safety at intersections.

Evaluating the effectiveness of new-designed crosswalk markings at intersections in China considering vehicle-pedestrian interaction

Crosswalk markings are a type of facility installed at the vehicle-pedestrian interaction locations and the function is to warn drivers to watch out for pedestrians crossing the street and improve safety for pedestrians. In Beijing, a type of new-designed crosswalk markings in China (NCMC) was installed. However, evaluating the effectiveness of this type of crosswalk markings was not conducted. Accordingly, the objective of this paper is to evaluate the effectiveness of this type of new-designed crosswalk markings. During the evaluation process, the vehicle-pedestrian interaction was considered; standard crosswalk markings in China (SCMC) were taken as a control group. In addition, empirical data were collected from a driving simulator, and nine evaluating indicators representing vehicle operating data, drivers' maneuvering data and drivers' subjective evaluation were proposed. In order to combine nine indicators, a Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method was used in this study to achieve the premium degrees of these two types of crosswalk markings. The evaluation result showed that, for intersections with high or low pedestrian flow, the comprehensive effectiveness and influences on drivers' driving behaviors with presence of NCMC were better than those with presence of SCMC, no matter where vehicle-pedestrian interactions occurred. For intersections with no pedestrians, the comprehensive effectiveness and influences on drivers' driving behaviors with presence of NCMC were worse than those with presence of SCMC, no matter where vehicle-pedestrian interaction occurred. These results may provide references for facility installing and future development of standards.

The relationship between impact speed and the probability of pedestrian fatality during a vehicle-pedestrian crash: A systematic review and meta-analysis

BACKGROUND

Pedestrians struck in motorised vehicle crashes constitute the largest group of traffic fatalities worldwide. Excessive speed is the primary contributory factor in such crashes. The relationship between estimated impact speed and the risk of a pedestrian fatality has generated much debate concerning what should be a safe maximum speed limit for vehicles in high pedestrian active areas.

METHODS

Four electronic databases (MEDLINE, EMBASE, COMPENDEX, and SCOPUS) were searched to identify relevant studies. Records were assessed, and data retrieved independently by two authors in adherence with the PRISMA statement. The included studies reported data on pedestrian fatalities from motorised vehicle crashes with known estimated impact speed. Summary odds ratios (OR) were obtained using meta-regression models. Time trends and publication bias were assessed.

RESULTS

Fifty-five studies were identified for a full-text assessment, 27 met inclusion criteria, and 20 were included in a meta-analysis. The analyses found that when the estimated impact speed increases by 1 km/h, the odds of a pedestrian fatality increases on average by 11% (OR = 1.11, 95% CI: 1.10-1.12). The risk of a fatality reaches 5% at an estimated impact speed of 30 km/h, 10% at 37 km/h, 50% at 59 km/h, 75% at 69 km/h and 90% at 80 km/h. Evidence of publication bias and time trend bias among included studies were found.

CONCLUSIONS

The results of the meta-analysis support setting speed limits of 30-40 km/h for high pedestrian active areas. These speed limits are commonly used by best practice countries that have the lowest road fatality rates and that practice a Safe System Approach to road safety.

A pedestrian serious injury risk prediction method based on posted speed limit

The purpose of this study was to develop a serious injury risk prediction algorithm for pedestrians, using data from the South Australian Traffic Accident Reporting System. Two algorithms were developed to estimate serious injury risk, using a logistic regression analysis of 6,868 vehicle-pedestrian crashes extracted from TARS data. In this study, an optimal model based on the best combination of risk factors according to the Akaike information criterion (AIC) was developed. Additionally, a secondary GPS model using only crash site characteristics that can be derived from GPS coordinates from the crash scene was also developed. The optimal model is based on site and environmental conditions that could be derived from GPS data (posted speed limit, distance from crash site, natural lighting conditions, road geometry, road horizontal alignment and road vertical alignment) as well as pedestrian age/gender, driver age/gender and vehicle model year. The second model only included features that could be derived from GPS data. The optimal model was reasonable in accuracy and gave an under-triage rate of 10% when the injury threshold was set to 15%, with a corresponding over-triage rate of around 60%. The GPS model, despite not being as accurate as the optimal model may be adequate in the absence of all the risk factors required for the optimal model, requiring an injury threshold of 20% to give an under-triage rate of 10%, with the corresponding over-triage rate being around 70%. Both models can potentially be used for serious injury risk prediction (SIRP) for pedestrians involved in a collision with a vehicle.

Novel Methods for Environmental Assessment of Pedestrian Injury: Creation and Validation of the Inventory for Pedestrian Safety Infrastructure

Nationally, 80% of pedestrian fatalities occur in urban environments, yet the distribution of injuries across urban areas is not uniform. Identifying street-level risk factors for pedestrian injury is essential for urban planning and improvement projects, as well as targeted injury prevention efforts. However, creating and maintaining a comprehensive database of a city's traffic safety infrastructure can be cumbersome and costly. The purpose of this study was to create and validate a neighborhood environmental observational assessment tool to capture evidence-based pedestrian safety infrastructure using Google Street View (GSV)-The Inventory for Pedestrian Safety Infrastructure (IPSI). We collected measures in-person at 172 liquor stores in Baltimore City from June to August 2015 to assess the tool's reliability; we then collected IPSI measures at the same 172 locations using GSV from February to March 2016 to assess IPSI reliability using GSV. The majority of items had good or excellent levels of inter-rater reliability (ICC ≥ 0.8), with intersection features showing the highest agreement across raters. Two scales were also developed using exploratory factor analysis, and both showed strong internal consistency (Cronbach's alpha ≥ 0.6). The IPSI provides a valid, economically efficient tool for assessing pedestrian safety infrastructure that can be employed for a variety of research and urban planning needs. It can also be used for in-person or GSV observation. Reliable and valid measurement of pedestrian safety infrastructure is essential to effectively prevent future pedestrian injuries.

The Effect of the Color of a Long Cane Used by Individuals who Are Visually Impaired on the Yielding Behavior of Drivers

Introduction

A new market trend offers long canes for individuals with visual impairments in a variety of colors; however, the impact of these colors is unknown to orientation and mobility (O&M) specialists and individuals who are blind or who have low vision. The authors examined the impact of cane color on drivers’ yielding behaviors; also, cane display effectiveness was assessed.

Methods

At traffic signal–controlled intersections, drivers’ yielding responses (yield–no yield and seconds to crosswalk) were recorded by two raters when a pedestrian presented one of two conditions (display and flagging) with four differently colored long canes (white, black, yellow, and green).

Results

In trials where the pedestrian used a flagging cane technique, the white cane achieved 290% more yielding than the green cane, 100% more yielding than the yellow cane, and 40% more yielding than the black. Statistical differences were found between the white-with-red cane and the yellow and green canes. The measure of drivers’ latency for moving forward was not statistically different between trials in which a pedestrian displayed a white cane at the crosswalk and trials in which no pedestrians were present.

Discussion

Cane color appears to have a substantial effect on drivers’ yielding responses. The results also indicate only a slight driver response to a highly visible cane display, confirming the results of previous studies that recommended more potent pedestrian movements to mitigate the threat from turning vehicles.

Implications for practitioners

O&M specialists and cane travelers need to consider the options for cane color when using a cane to cross streets. A white cane, flagged at the onset of the walk signal, can achieve more desirable responses from drivers than can the long canes of other colors. More effective cane behaviors exhibited by pedestrians who are visually impaired should always be considered by O&M instructors in order to influence drivers.

Analysis of risk factors affecting driver injury and crash injury with drivers under the influence of alcohol (DUI) and non-DUI

OBJECTIVE

The objective of this research was to study risk factors that significantly influence the severity of crashes for drivers both under and not under the influence of alcohol.

METHODS

Ordinal logistic regression was applied to analyze a crash data set involving drivers under and not under the influence of alcohol in China from January 2011 to December 2014.

RESULTS

Four risk factors were found to be significantly associated with the severity of driver injury, including crash partner and intersection type. Age group was found to be significantly associated with the severity of crashes involving drivers under the influence of alcohol. Crash partner, intersection type, lighting conditions, gender, and time of day were found to be significantly associated with severe driver injuries, the last of which was also significantly associated with severe crashes involving drivers not under the influence of alcohol.

CONCLUSIONS

This study found that pedestrian involvement decreases the odds of severe driver injury when a driver is under the influence of alcohol, with a relative risk of 0.05 compared to the vehicle-to-vehicle group. The odds of severe driver injury at T-intersections were higher than those for traveling along straight roads. Age was shown to be an important factor, with drivers 50-60 years of age having higher odds of being involved in severe crashes compared to 20- to 30-year-olds when the driver was under the influence of alcohol. When the driver was not under the influence of alcohol, drivers suffered more severe injuries between midnight and early morning compared to early nighttime. The vehicle-to-motorcycle and vehicle-to-pedestrian groups experienced less severe driver injuries, and vehicle collisions with fixed objects exhibited higher odds of severe driver injury than did vehicle-to-vehicle impacts. The odds of severe driver injury at cross intersections were 0.29 compared to travel along straight roads. The odds of severe driver injury when street lighting was not available at night were 3.20 compared to daylight. The study indicated that female drivers are more likely to experience severe injury than male drivers when not under the influence of alcohol. Crashes between midnight and early morning exhibited higher odds of severe injury compared to those occurring at other times of day. The identification of risk factors and a discussion on the odds ratio between levels of the impact of the driver injury and crash severity may benefit road safety stakeholders when developing initiatives to reduce the severity of crashes.

Analyzing pedestrian crash injury severity at signalized and non-signalized locations

This study identifies and compares the significant factors affecting pedestrian crash injury severity at signalized and unsignalized intersections. The factors explored include geometric predictors (e.g., presence and type of crosswalk and presence of pedestrian refuge area), traffic predictors (e.g., annual average daily traffic (AADT), speed limit, and percentage of trucks), road user variables (e.g., pedestrian age and pedestrian maneuver before crash), environmental predictors (e.g., weather and lighting conditions), and vehicle-related predictors (e.g., vehicle type). The analysis was conducted using the mixed logit model, which allows the parameter estimates to randomly vary across the observations. The study used three years of pedestrian crash data from Florida. Police reports were reviewed in detail to have a better understanding of how each pedestrian crash occurred. Additionally, information that is unavailable in the crash records, such as at-fault road user and pedestrian maneuver, was collected. At signalized intersections, higher AADT, speed limit, and percentage of trucks; very old pedestrians; at-fault pedestrians; rainy weather; and dark lighting condition were associated with higher pedestrian severity risk. For example, a one-percent higher truck percentage increases the probability of severe injuries by 1.37%. A one-mile-per-hour higher speed limit increases the probability of severe injuries by 1.22%. At unsignalized intersections, pedestrian walking along roadway, middle and very old pedestrians, at-fault pedestrians, vans, dark lighting condition, and higher speed limit were associated with higher pedestrian severity risk. On the other hand, standard crosswalks were associated with 1.36% reduction in pedestrian severe injuries. Several countermeasures to reduce pedestrian injury severity are recommended.

Pedestrian signalization and the risk of pedestrian-motor vehicle collisions in Lima, Peru

Safe walking environments are essential for protecting pedestrians and promoting physical activity. In Peru, pedestrians comprise over three-quarters of road fatality victims. Pedestrian signalization plays an important role managing pedestrian and vehicle traffic and may help improve pedestrian safety. We examined the relationship between pedestrian-motor vehicle collisions and the presence of visible traffic signals, pedestrian signals, and signal timing to determine whether these countermeasures improved pedestrian safety. A matched case-control design was used where the units of study were crossing locations. We randomly sampled 97 control-matched collisions (weighted N=1134) at intersections occurring from October, 2010 to January, 2011 in Lima. Each case-control pair was matched on proximity, street classification, and number of lanes. Sites were visited between February, 2011 and September, 2011. Each analysis accounted for sampling weight and matching and was adjusted for vehicle and pedestrian traffic flow, crossing width, and mean vehicle speed. Collisions were more common where a phased pedestrian signal (green or red-light signal) was present compared to no signalization (odds ratio [OR] 8.88, 95% Confidence Interval [CI] 1.32-59.6). A longer pedestrian-specific signal duration was associated with collision risk (OR 5.31, 95% CI 1.02-9.60 per 15-s interval). Collisions occurred more commonly in the presence of any signalization visible to pedestrians or pedestrian-specific signalization, though these associations were not statistically significant. Signalization efforts were not associated with lower risk for pedestrians; rather, they were associated with an increased risk of pedestrian-vehicle collisions.

Conditions that Influence Drivers’ Yielding Behavior in Turning Vehicles at Intersections with Traffic Signal Controls

Introduction

This study evaluated drivers’ delays and yields in response to pedestrian behaviors when making right turns at the onset of a green traffic signal.

Methods

Researchers conducted trials at seven sites in the United States. Data were collected ( n = 445) in six conditions: no pedestrian present (control); and a pedestrian: standing with no cane (control), displaying a cane, flagging a cane, putting a hand up toward the driver, or taking a reversible step into the street. Driver delays were recorded in seconds from the onset of the green traffic signal to when the vehicle first moved and when the front bumper crossed the middle of the pedestrian's crosswalk.

Results

Regarding driver responses when the vehicle crossed the crosswalk: a cane display was not significantly different from no cane display; the cane-flagging, reversible-step, and hand-up conditions were all significantly better than a cane display; a reversible step was significantly better than both cane flagging and hand up. Analysis of yields found that: a cane display was not significantly different from not displaying a cane; cane flagging, reversible step, and hand up were all significantly better than the cane display; a reversible step was significantly better than both hand up and cane flagging. The greatest effect was the reversible step, which increased drivers’ yielding 205% more often than a pedestrian displaying a cane.

Implications for practitioners

For drivers to behave appropriately, they must notice the pedestrian and understand the intent to initiate a crossing. The standard practices taught by O&M specialists may not result in substantial yielding by drivers. O&M specialists could develop new and more effective practices based on these results in order to change risks for pedestrians who are blind or visually impaired when crossing many streets.

Association between neighbourhood marginalization and pedestrian and cyclist collisions in Toronto intersections

OBJECTIVE

Pedestrian and cyclist collisions comprise a significant proportion of preventable injury. In urban settings, collision rates have been linked to various socio-demographic factors. We sought to determine whether neighbourhood marginalization affects pedestrian and cyclist collisions in the Greater Toronto Area.

METHODS

For 114 intersections, pedestrian and cyclist collisions were extracted from the Toronto Traffic Data Centre database. We used a geographic information system approach to determine census Dissemination Areas and an associated Ontario Marginalization Index (ON-Marg) for each intersection. We performed a logistic regression to examine the associations between the four ON-Marg dimensions (residential instability, material deprivation, dependency, ethnic concentration) and pedestrian and cyclist collisions.

RESULTS

The odds of sustaining a collision were independently associated with residential instability for both pedestrians (OR 1.84, 95% CI 1.21-2.84, p=0.006) and cyclists (OR 2.04, 95% CI 1.34-3.16, p=0.001). Higher overall collision rates (both pedestrian and cyclist) were associated with both ethnic concentration (OR 1.56, 95% CI 1.05-2.37, p=0.033) and residential instability (OR 2.16, 95% CI 1.43-3.38, p=0.001). Material deprivation and dependency were not significant risk factors for intersection collisions in this model.

CONCLUSIONS

Collisions involving pedestrians and cyclists are more common in areas of increased residential instability and ethnic concentration in Toronto. Intersections in neighbourhoods with these characteristics could be targeted for strategies to reduce pedestrian and cyclist injury risk in urban settings.

Auditory perception of motor vehicle travel paths

OBJECTIVE

These experiments address concerns that motor vehicles in electric engine mode are so quiet that they pose a risk to pedestrians, especially those with visual impairments.

BACKGROUND

The "quiet car" issue has focused on hybrid and electric vehicles, although it also applies to internal combustion engine vehicles. Previous research has focused on detectability of vehicles, mostly in quiet settings. Instead, we focused on the functional ability to perceive vehicle motion paths.

METHOD

Participants judged whether simulated vehicles were traveling straight or turning, with emphasis on the impact of background traffic sound.

RESULTS

In quiet, listeners made the straight-or-turn judgment soon enough in the vehicle's path to be useful for deciding whether to start crossing the street. This judgment is based largely on sound level cues rather than the spatial direction of the vehicle. With even moderate background traffic sound, the ability to tell straight from turn paths is severely compromised. The signal-to-noise ratio needed for the straight-or-turn judgment is much higher than that needed to detect a vehicle.

CONCLUSION

Although a requirement for a minimum vehicle sound level might enhance detection of vehicles in quiet settings, it is unlikely that this requirement would contribute to pedestrian awareness of vehicle movements in typical traffic settings with many vehicles present.

APPLICATION

The findings are relevant to deliberations by government agencies and automobile manufacturers about standards for minimum automobile sounds and, more generally, for solutions to pedestrians' needs for information about traffic, especially for pedestrians with sensory impairments.

Analysis of risk factors affecting the severity of intersection crashes by logistic regression

OBJECTIVE

The objective of this research was to study the risk factors that significantly influence the severity of intersection crashes for vehicle occupants, as well as for pedestrians and other vulnerable road users.

METHODS

Logistic regression was applied as the method in this study to analyze a data set of intersection crashes involving casualties in Victoria, Australia, for the period January 2000 to December 2009.

RESULTS

Seven risk factors obtained were found to be significantly associated with the severity of intersection crashes, including driver age and gender, speed zone, traffic control type, time of day, crash type, and seat belt usage.

CONCLUSIONS

This study found that male drivers as well as older drivers (age 65 and above) had higher odds of being involved in fatal intersection crashes. Intersection crashes occurring between midnight and early morning (12:00 a.m. to 5:59 a.m.), in 100 km/h speed zones, or with no traffic control had a higher odds of a fatal outcome than their counterpart categories. Furthermore, intersection crashes involving pedestrians or a non-seat belt-wearing driver were more likely to lead to a fatal outcome. In general, identification of risk factors and the discussion of the odds ratio between levels on the impact of the intersection crash severity would be beneficial for road safety stakeholders to develop initiatives to reduce the severity of intersection crashes.