Article

The impact of pedestrian countdown signals on pedestrianemotor vehicle collisions: A quasi-experimental study

Child Health Evaluative Sciences, The Hospital for Sick Children, , Toronto, Ontario, Canada.
Injury Prevention (Impact Factor: 1.89). 09/2013; 18(4). DOI: 10.1136/injuryprev-2012-040717
Source: PubMed

ABSTRACT

To perform a more sophisticated analysis of previously published data that advances the understanding of the efficacy of pedestrian countdown signal (PCS) installation on pedestrian-motor vehicle collisions (PMVCs), in the city of Toronto, Canada.
This is an updated analysis of the same dataset from Camden et al. A quasi-experimental design was used to evaluate the effect of PCS on PMVC. A Poisson regression analysis, using a one-group comparison of PMVC, pre-PCS installation to post-PCS installation was used, controlling for season and temporal effects. The outcome was the frequency of reported PMVC (January 2000-December 2009). Similar models were used to analyse specific types of collisions defined by age of pedestrian, injury severity, and pedestrian and vehicle action. Incidence rate ratios with 95% CI are presented.
This analysis included 9262 PMVC, 2760 during or after PCS installation, at 1965 intersections. There was a 26% increase in the rate of collisions, pre to post-PCS installation (incidence rate ratio=1.26, 95% CI 1.11 to 1.42).
The installation of PCS at 1965 signalised intersections in the city of Toronto resulted in an increase in PMVC rates post-PCS installation. PCSs may have an unintended consequence of increasing pedestrian-motor vehicle collisions in some settings.

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    • "Similar to prior studies, we demonstrated that extensive fieldwork could potentially be avoided by taking advantage of various detailed geospatial local government data to assess built environment at both micro-and macro-environmental levels in relation to road safety (Lee and Abdel-Aty, 2005; Miranda-Moreno et al., 2011; Vernez Moudon et al., 2011; Chen et al., 2013). Using detailed government data on road safety and the environment helps expand the number of sample locations to those of an entire city, county or state for evaluating specific changes (Chen et al., 2013, 2015; Richmond et al., 2014). This approach could be used to identify problematic locations in a city or region that could then be examined more thoroughly in terms of infrastructure, environment and road user behaviors. "
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    ABSTRACT: 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. Copyright © 2015 Elsevier Ltd. All rights reserved.
    No preview · Article · Aug 2015 · Accident; analysis and prevention
    • "Similar to prior studies, we demonstrated that extensive fieldwork could potentially be avoided by taking advantage of various detailed geospatial local government data to assess built environment at both micro-and macro-environmental levels in relation to road safety (Lee and Abdel-Aty, 2005; Miranda-Moreno et al., 2011; Vernez Moudon et al., 2011; Chen et al., 2013). Using detailed government data on road safety and the environment helps expand the number of sample locations to those of an entire city, county or state for evaluating specific changes (Chen et al., 2013, 2015; Richmond et al., 2014). This approach could be used to identify problematic locations in a city or region that could then be examined more thoroughly in terms of infrastructure, environment and road user behaviors. "
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    ABSTRACT: Statement of purpose A safe walking environment may improve public health by facilitating environmental health, physical activity and injury prevention. We studied the walking behaviour of adult pedestrians to examine the relationship between walking and walking route safety. Methods A cross-sectional study of adults in King County, WA in 2007–2008 assessed walking using accelerometry with spatial location via Global Positioning System (GPS) devices and travel diaries. GPS and accelerometer readings were logged every 30 s for up to 7 days. Participants were included if they had at least one walking “bout” in Seattle, WA city boundaries (N = 548). Bouts were spatially matched to Seattle intersection and mid-block locations. The historical probability of a pedestrian-motor vehicle collision during 2007–2013 at each intersection and mid-block was predicted in a random-effects Poisson model which included road characteristics (e.g., traffic volume), built environment features (e.g., sidewalks) and neighbourhood characteristics (e.g., residential density). Multilevel mixed-effects linear regression was used to assess the average safety of walking routes (mean exposure to pedestrian collision risk) and individual walking (accelerometer counts, bout length, and bout time) and demographic characteristics. Results Pedestrians who walked longer had safer walking routes (−2.65% historical probability of pedestrian collision along the route per 10 min of walking, 95% CI −3.54%, −1.76%). Female pedestrians more commonly had safer walking routes relative to males (−1.10%, 95% CI −0.17%, −2.02%), as did people who owned at least one motor vehicle (−3.98%, 95% CI −5.07%, −2.90%). Conclusions These findings may indicate that people who walk more are significantly less likely to walk in areas with a higher risk of pedestrian collisions. Pedestrians who walk more may avoid areas that are perceived or experienced as higher risk to pedestrians. Significance and contributions Our findings suggest that environmental changes to improve safety for walkers may encourage pedestrian activity.
    No preview · Article · Apr 2015 · Injury Prevention
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    • "In Lima, few intersections have an exclusive left-turn phase, thus many turning vehicles compete with pedestrians crossing in the path of the turning vehicle. There is evidence from at least one study that may indicate that pedestrian countdown signals like those observed in this study may be have a slightly higher risk of pedestrian collisions (Richmond et al., 2013), though other smaller studies have observed a potential improvement in pedestrian safety with these signals (Schattler et al., 2007; Nambisan and Karkee, 2010; Pulugurtha et al., 2010). There were some study limitations as it is recognized that police-reported data are not always ideal for research (Secretaría Técnica Del Consejo De Transporte De Lima Y Callao, 2011). "
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