Article

Pedestrian countdown signals: Experience with an extensive pilot installation

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Abstract

San Francisco, CA, USA's pilot pedestrian countdown signals were associated with a decrease in pedestrian injuries and fewer pedestrians finishing crossing on red. This feature discusses the impacts of the popular devices on collisions, pedestrian behavior and attitudes, motorist behavior and signal.

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... Countdown timers are adopted (permanently or for trial) in several countries as: United Kingdom, Canada, USA, China, Australia, South Korea, New Zealand, Serbia et al. Studies have shown that crossing facilities with countdown timers provide a sense of safety to pedestrians (Markowitz, Sciortino, Fleck, & Yee, 2006;Xiong et al., 2014;York et al., 2011). The timers are considered as helpful, easy to understand and they are generally preferred compare to conventional traffic signal systems. ...
... The same authors also observed statistical significant increase of the walking speed, after the countdown timer implementation. Finally, Markowitz et al. (2006) found that countdown timers led to a decrease of pedestrians on the crosswalk when the light turned red. This outcome is justified by the rush of pedestrians to complete the crossing in time and not due to their legal behaviour. ...
... Moreover, elder pedestrians were found more compliant than younger (Li, 2014;Lipovac et al., 2013;Vujanić et al., 2014;Zhou et al., 2011). Research has also shown that pedestrians evaluate the remaining time of the countdown timers and adapt their behaviour and speed (Brown et al., 2010;Huang & Zegger, 2000;Markowitz et al., 2006). Additionally, in many cases an increased number of late starters or/and finishers was observed (Vujanić et al., 2014;Wanty & Wilkie, 2010). ...
Article
Although they are aware of the possible risk, a high number of pedestrians still violate the red light indication and cross the road illegally. This hazardous behaviour may cause incidents between them and the road vehicles. In order to reduce this illegal behaviour, the traffic signals are equipped with countdown timers, in order to provide more information and decrease pedestrians’ noncompliant behaviour. The main purpose of the present paper is to investigate the influence of countdown timers on pedestrians’ compliance regarding their crossing behaviour at intersections as well as to examine the parameters affecting walking speed adaptation. In the context of this analysis two regression models were developed. The first model is a binary logistic regression model which examines pedestrians’ self reported compliance. The results showed that the gender, the age, the perceived comfort and the seconds remaining for the onset of red light are the main parameters that affect compliance. The second model is an ordinal regression model which examines the factors that make pedestrians adapt their walking speed as they are crossing the road and are informed by the countdown timers about the second remaining for the termination of the green phase. The results of the second model revealed that the age, the compliance and the perceived assistance that the countdown timer provides for the walking speed adaptation affect the minimum remaining time before a pedestrian accelerates.
... As in the case of pedestrian-vehicle conflicts, a study done in San Francisco resulted in a 52% decrease in pedestrian crashes due to PCTs [19]. However, this may not be a significant decrease if one was to consider the change in the number of crashes at the control intersections. ...
... In some studies, authors have concluded that there is a positive impact on pedestrian behaviour [1], [7], [10], [13], [15], [24]. Other studies however, found little evidence of the influence of countdown signals and suggested conducting further researches [18], [19], [25], [26]. ...
... Research conducted by The Minnesota Department of Transportation (MnDOT) found a significant increase of in successful pedestrian crossings due to the installation of PCTs [19]. Similarly, [28]- [30]. ...
... This implied that all the pedestrian lights in this study had only two phases (green/red) and that there were no count-down signals. At present, lights of the latter type are rare in Belgium and there is evidence that pedestrians behave quite differently in their presence (e.g., Eccles et al., 2007;Markowitz et al. 2006;Schlabbach, 2010). A complete list of observation sites is available in Diependaele (2015). ...
... Waiting times after requests are generally not transparent. The lack of transparent information about waiting times has indeed been shown to exert a strong negative influence on safe crossing behaviour by pedestrians (e.g., Eccles et al., 2007;Markowitz et al. 2006;Schlabbach, 2010). ...
... In principle, such signals can be additional light sources, messages (e.g., confirmation of push button request), intermittent light during phase changes and count-down displays. Although the latter types of visual feedback are rare in Belgium (and were not present in the current study), especially countdown displays appear to have an important positive effect on compliance (e.g., Eccles et al., 2007;Markowitz et al. 2006;Schlabbach, 2010). ...
Preprint
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The frequency of red light running was investigated across the nine most populated cities in Belgium. The results show that approximately 21% of the pedestrians violate the lights. There is, however, large variability in the frequency of violations depending on the specific context. Traffic volumes, motorized as well as pedestrian volumes, and situational characteristics that are generally associated with higher traffic complexity (rush hours, number of driving directions, number of lanes per driving direction and the presence of a tram or bus lane) have a lowering effect. A number of technical characteristics of the pedestrian crossing were also found to exert a significant influence: push buttons and worn off zebra markings increase the frequency of violations. On the other hand, auxiliary signals, either visual or auditory, have a positive effect.
... A CMF of 0.75 for pedestrian crashes was developed from one study of the effects of replacing traditional walk/don't walk pedestrian signals with pedestrian countdown signal heads (Toolbox of Countermeasures and Their Potential Effectiveness for Pedestrian Crashes 2013, citing Markowitz et al. 2006). However, other studies have found more mixed results from widespread installation. ...
... -The decrease in pedestrian crashes was greater for the treated intersections with high crashes compared with the untreated group with high crashes. Markowitz et al. (2006) Traffic signal with pedestrian countdown signal ...
Technical Report
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This synthesis summarizes the types of pedestrian crossing treatments being used in different places throughout the United States, and what policies and processes are used to select and prioritize treatments and treatment locations. The study was developed by (1) surveying state departments of transportation and local transportation agencies, (2) identifying and synthesizing effective practices and policies, and (3) performing a comprehensive literature review of safety evidence for more than 25 pedestrian crossing treatments. Case examples highlight more comprehensive pedestrian safety practices.
... When it comes to the efficiency of the countdown displays, some authors highlight their positive influence on pedestrian behavior (Eccles et al., 2004;Harre & Wrapson, 2004;Kennedy & Sexton, 2009;Lambrianidou, Basbas, & Politis, 2012;Keegan & O'Mahony, 2003;Lipovac, Vujanic, Maric, & Nesic, 2013), while the others do not have a final position on the impact of countdown displays, that are based on the obtained results, and therefore recommend undertaking further researches (Botha, Zabyshny, & Day, 2002;Camden, Buliung, Rothman, Macarthur, & Howard, 2011;Markowitz, Sciortino, Fleck, & Bond, 2006;Reddy, Datta, Savolainen, & Pinapaka, 2008;Zegeer & Huang, 2000). The study of pedestrian behavior at 14 intersections in San Francisco (Markowitz et al., 2006), shows that after the countdown display was installed, the percentage of pedestrians who started crossing the road during the flashing red light (''flashing Do not Walk''), was slightly, but not significantly increased. ...
... When it comes to the efficiency of the countdown displays, some authors highlight their positive influence on pedestrian behavior (Eccles et al., 2004;Harre & Wrapson, 2004;Kennedy & Sexton, 2009;Lambrianidou, Basbas, & Politis, 2012;Keegan & O'Mahony, 2003;Lipovac, Vujanic, Maric, & Nesic, 2013), while the others do not have a final position on the impact of countdown displays, that are based on the obtained results, and therefore recommend undertaking further researches (Botha, Zabyshny, & Day, 2002;Camden, Buliung, Rothman, Macarthur, & Howard, 2011;Markowitz, Sciortino, Fleck, & Bond, 2006;Reddy, Datta, Savolainen, & Pinapaka, 2008;Zegeer & Huang, 2000). The study of pedestrian behavior at 14 intersections in San Francisco (Markowitz et al., 2006), shows that after the countdown display was installed, the percentage of pedestrians who started crossing the road during the flashing red light (''flashing Do not Walk''), was slightly, but not significantly increased. It was found that there was a statistically significant increase in the percentage of slow pedestrians, i.e. pedestrians who started crossing the road during the pedestrian green light, and finished it at the pedestrian red light (''steady Do not Walk''), regardless of the actual evacuation time for pedestrians (TRL, 2006). ...
Article
Full-text available
Pedestrian behavior has been a subject of surveys carried out at two signalized pedestrian crossings, in the city of Doboj (BIH, Republic of Srpska). The analysis is made on the basis of video recordings, and includes behavior at pedestrian crossings, in various conditions (two locations, different vehicle flows, with or without a countdown display). The analysis also includes the distribution of illegal crossings (at the pedestrian red light) of different categories of pedestrians (gender, age), before and after the installation of a pedestrian countdown display, at two different pedestrian crossings. The results of the study have shown that a countdown display reduces statistically significantly the total number of violators, regardless of its location and traffic flow. However, this reduction is not the same at various categories of pedestrians (male, female, elderly, young people). The influence of the display has been particularly dominant at the pedestrian crossing located outside the centre of the city, with the smaller intensity of traffic. Children pedestrians do not accept the behavior in accordance with the countdown display in case of a reduced intensity of traffic, at a pedestrian crossing located in the backstreet. A countdown display does not statistically significantly change the distribution form of the number of offences during the red light for pedestrians, regardless of the pedestrian environment. However, there is a statistically significant difference in certain intervals (during the first and last 4 s) in the total distribution, as well as in the categories (female pedestrians, children). A countdown display does not reduce the overall number of “slow” pedestrians, but the impact on certain categories of “slow” pedestrians (gender/children), as well as on pedestrian violators, per age categories, varies depending on the location and traffic flow at an intersection.
... 9 Very few studies have examined the effects of PCS on actual pedestrian motor vehicle collisions (PMVC) on a city-wide level and existing studies have shown contradictory results. [14][15][16][17] In Toronto, Canada, PCS were installed at the majority of signalised intersections between the end of 2006 and 2011. An analysis of police reported PMVC data before and after 1,965 of these installations, published in 2013, found a 26% increase in the rate of collisions afetr installation, while controlling for pre-PCS collision rates at each intersection and temporal and seasonal effects. ...
... If PCS safety effectiveness varies within a city, then it follows that effectiveness will certainly vary across cities, resulting in the discrepant findings in the literature. [14][15][16][17] Studies reporting decreased collisions with PCS installation include those with limited numbers of intersections, potentially biased by regression to the mean effects due to their design 15 16 and studies that have not controlled for pre-intervention PMVC rates or seasonal effects. 17 The strongest spatial patterns were most evident in adults, who represent the largest number of PMVC. ...
Article
Background Pedestrian countdown signals (PCS) have been installed in many cities over the last 15 years. Few studies have evaluated the effectiveness of PCS on pedestrian motor vehicle collisions (PMVC). This exploratory study compared the spatial patterns of collisions pre and post PCS installation at PCS intersections and intersections or roadways without PCS in Toronto, and examined differences by age. Methods PCS were installed at the majority of Toronto intersections from 2007 to 2009. Spatial patterns were compared between 4 years of police-reported PMVC prior to PCS installation to 4 years post installation at 1864 intersections. The spatial distribution of PMVC was estimated using kernel density estimates and simple point patterns examined changes in spatial patterns overall and stratified by age. Areas of higher or lower point density pre to post installation were identified. Results There were 14 911 PMVC included in the analysis. There was an overall reduction in PMVC post PCS installation at both PCS locations and non-PCS locations, with a greater reduction at non-PCS locations (22% vs 1%). There was an increase in PMVC involving adults (5%) and older adults (9%) at PCS locations after installation, with increased adult PMVC concentrated downtown, and older adult increases occurring throughout the city following no spatial pattern. There was a reduction in children’s PMVC at both PCS and non-PCS locations, with greater reductions at non-PCS locations (35% vs 48%). Conclusions Results suggest that the effects of PCS on PMVC may vary by age and location, illustrating the usefulness of exploratory spatial data analysis approaches in road safety. The age and location effects need to be understood in order to consistently improve pedestrian mobility and safety using PCS.
... Markowitz et al. conducted one of the first crash-based evaluation of PCS (3). The authors examined pedestrian injury events at nine pilot PCS intersections in San Francisco. ...
Article
Full-text available
The pedestrian countdown signals (PCS) treatment involves the display of a numerical countdown that shows how many seconds are left in the flashing DON’T WALK interval. Although many studies have attempted to evaluate the safety of PCS, the results have been inconsistent for many reasons, including inadequate sample size and the inability to control for possible bias from regression to the mean and from exposure. This study performed a before-after empirical Bayes analysis using data from 115 treated intersections in Charlotte, North Carolina and 218 treated intersections in Philadelphia, Pennsylvania to evaluate the safety effects of PCS. The evaluation also included 136 reference intersections in Charlotte, and 597 reference intersections in Philadelphia. Following the implementation of PCS, total crashes decreased by approximately 8% and rear-end crashes decreased by approximately 12%, and these reductions were statistically significant at the 95% confidence level. Pedestrian crashes decreased by about 9% and this reduction was statistically significant at the 90% confidence level. Economic analysis revealed a benefit-cost ratio of 23 with a low of 13 and a high of 32.
... Consequently, many studies found PCT to be very effective in increasing pedestrian crossing speed [8,9]. Few studies observed that the time remaining for each of these phases helped in increasing the pedestrian safety at signalized intersections [1,9,10,11]. Another study by Kapoor and Magesan [12] showed that PCT has different effects on different road users. ...
... Generally, pedestrian countdown signals are used to display the number of remaining seconds at the beginning of the FLASHING DON'T WALK (FDW) signal phase. Some studies have confirmed that pedestrian countdown signals had generally positive effects on pedestrian behavior, because they showed the time remaining which was helpful for crossing (Harre and Wrapson, 2004;Eccles et al., 2004;Markowitz et al., 2006;Kim et al., 2002;Xiong et al., 2014). It was precisely because of the information showed by countdown signal, late starters increased at the intersections with countdown signals (Hooper et al., 2007;Wanty and Wilkie, 2010;Cleaver et al., 2011). ...
Article
Previous studies have shown that pedestrian countdown signals had different influences on pedestrian crossing behavior. The purpose of this study was to examine the effects of the installation of countdown signals at school intersections on children’s crossing behavior. A comparison analysis was carried out on the basis of observations at two different school intersections with or without pedestrian countdown signals in the city of Jinan, China. Four types of children’s crossing behavior and child pedestrian-vehicle conflicts were analyzed in detail. The analysis results showed that using pedestrian countdown timers during the Red Man phase led to more children’s violation and running behavior. Theses violators created more conflicts with vehicles. However, pedestrian countdown signals were effective at helping child pedestrian to complete crossing before the red light onset, avoid getting caught in the middle of crosswalk. No significant difference was found in children who started crossing during Flashing Green Man phase between the two types of pedestrian signals. Moreover, analysis results indicated that children who crossed the road alone had more violation and adventure crossing behavior than those had companions. Boys were found more likely to run crossing than girls, but there was no significant gender difference in other crossing behavior. Finally, it’s recommended to remove countdown at the end of the Red Man phase to improve children’s crossing behavior and reduce the conflicts with vehicles. Meanwhile other measures are proposed to improve children safety at school intersections.
... Lambrianidoua et al. indicated that the countdown signals were able to provide pedestrians with valuable information that enhanced the safety level as far as crossing of the intersection was concerned [7]. Pilot installations in San Francisco, USA, showed a 52% reduction in pedestrian injury collisions due to countdown signals [8]. Keegana and O'Mahonyb observed an 11% increase of people starting to cross the intersection during the steady "Walk" and flashing "Don't Walk" signals [9]. ...
Article
Full-text available
The objective of this research is to evaluate the impact of pedestrian countdown signals on crossing behavior at intersections. Data were collected by means of questionnaire and video recording at two signalized intersections: one was with pedestrian countdown signal and the other was with traditional signal. The questionnaire aims to reveal pedestrians' preference to countdown signals. It shows that 91.8% of pedestrians believe that countdown signals are helpful in determining the time to enter crosswalk, and 72.6% of pedestrians think that countdown signals are more comfortable for crossing. To evaluate effects of countdown signals, four measures of effectiveness, that is, proportion of compliers, adventurers, violators, and trapped pedestrians, are applied. Hypothesis testing results show that countdown signals can significantly increase proportions of compliers and reduce proportions of violators and trapped pedestrians compared with traditional signals. However, countdown signals have weak impact on adventurers since many pedestrians do not understand the meaning of flashing signal.
... However, several studies indicated that PCS may actually increase the percentage of pedestrians who start crossing on Flashing Don't Walk (FDW) signal (illegal entry) as they may realize that they still have enough time to complete their crossing safely. A large San Francisco, CA study [1] found that PCS brought an impressive 52% reduction in pedestrian injury as well as statistically significant decrease in exit violations and in running or aborting crossing. At the same time, there was a slight (and statistically not significant) increase in the entry violations. ...
Article
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This paper examines safety impacts of a Pedestrian Countdown Signal (PCS) installed on a busy downtown intersection in San Diego, California. Crossing episodes of over 5000 pedestrians were videotaped and analyzed using multivariate statistical methods. Details of timing of pedestrian crossing as well as information about vehicular traffic and signal timing were carefully coded for each pedestrian. Significant safety benefits of the PCS system were found on the long crossings over a street with high vehicular volumes: most pedestrians were able to effectively increase their walking speed to complete their crossing without committing the exit violation—even if they have already committed the entry violation. However, on the short crossing with light vehicular traffic, PCS was generally ineffective in preventing the entry violations from becoming exit violations. Over there, many pedestrians felt safe enough to walk over a short crossing with no apparent vehicular traffic in sight instead of waiting for a green signal. The length of crossing and volume of interfering vehicular traffic were consistently found the most significant variables affecting the crossing violation rates of different categories of pedestrians. Crossing violation rates were the highest for runners, bicyclists and older males. Crossing violation characteristics were found to be consistent over time.
... However, these results have not been statistically tested. As for the research of Markowitz et al. (2006), no statistically significant differences were found or confirm that a smaller number of pedestrians started to cross the road at the flashing red light and at the red light alone, after a countdown display had been installed. Jiang et al. (2011) observed pedestrian behavior at pedestrian crossings with traffic lights in urban areas. ...
Article
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The objective of this research was to define eventual differences in models of pedestrian behavior at signalized pedestrian crossings, with and without countdown displays. The outcomes of this work represent a contribution to the harmonization of positions on the effect of a countdown display on pedestrian behavior. Video recordings at two completely similar pedestrian crossings enabled the collection of pedestrian behavior data (crossing at the red light), which included different categories (gender, age, individual/group, and "slow" pedestrians), collected in different conditions (during certain red light intervals and traffic volume). The results of the research showed that a statistically significant larger number of pedestrian offenders occurred at pedestrian crossings without countdown displays rather than at crossings with countdown displays. The presence of a countdown display significantly reduced the number of women offenders in particular. The number of offenders in the first and last four seconds of the pedestrian red light at the pedestrian crossing with a countdown display, differed, in terms of statistical significance, from the number of offenders at the crossing without a countdown display. The countdown display had a positive influence on pedestrians older than 40 years of age, as well as on slow pedestrians. DOI:10.1061/(ASCE)TE.1943-5436.0000491. (C) 2013 American Society of Civil Engineers.
... As Lipovac et al. (2013) reported, published results so far do not present a consistent view concerning the impact of countdown displays. For example, a study in San Francisco shows that after the countdown display was installed, the percentage of pedestrians who started crossing the road during the blinking red pedestrian light (i.e. the ''Do not Walk''), was slightly higher, even though not statistically significant (Markowitz et al., 2006). Similarly, a research by Schmitz, cited in Lipovac et al. (2013) observed that a countdown display increased the walking speed of pedestrians when crossing the road. ...
Article
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Aging population and reductions in car use by seniors have the potential to increase active transportation rates. While there are associated health benefits to this potential shift, there are also higher risks for elderly pedestrian injuries, especially at street crossings. This naturalistic study compares street crossing behaviors of different population age groups in large Québec cities through observational data, situational characteristics and environmental characteristics of location. We assess if observed crossings could be completed safely within the allocated time. Street crossing observations on 2073 pedestrians was gathered at 135 signalized crossings during a four-month period in the summer of 2013. Mixed effect logit models are used to assess the individual, contextual, behavioral and environmental correlates of street crossing ending. Differences in age groups and other correlates are assessed for their association with the type of street crossing ending (on red light, on red hand or on both). In multivariate models, older age did not have an impact on finishing crossing on time, but many factors associated with older age were: having a walking aid, hesitating, and slowing down mid-crossing. Longer “white man silhouette” timing was also associated with reduced odds ratio of failing to finish crossing on time. The presence of cycling infrastructure increased those odds. Without walking, many elders will experience decreasing level of access. In neighborhoods with high concentrations of elderly populations, providing shorten crossing distance or longer crossing timing, may increase the convenience of walking for elderly populations. Longer signal timing may also be warranted in locations where cycling infrastructures were added to account for the increased level of difficulty.
... Applications of CPSD to only the FDW indication have also been the subject of research studies, which also found pedestrians to be in favour of the devices (Arhin and Noel, 2007;Schattler et al., 2007;Singer and Lerner, 2005). Several studies have indicated that countdown pedestrian signals are effective in enhancing pedestrian safety (Pulugurtha et al., 2010;Schattler et al., 2007), and both pedestrians and drivers have been found to make better decisions using the time left to cross the street displayed on pedestrian countdown signals at signalised intersections (Eccles et al., 2004;Markowitz et al., 2006;Tidwell and Doyle, 1995). By contrast, the results of an evaluation conducted in the District of Columbia were not statistically conclusive about the positive impacts of CPSD on pedestrian safety at the majority of intersections, nor were the results indicative of any adverse pedestrian behaviour caused by CPSD (Arhin and Noel, 2007). ...
Article
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The installation of countdown pedestrian signal display at signalised intersections was proposed as part of an overall strategy for improving pedestrian safety, especially at such intersections. Based on field observations of critical pedestrian-related parameters at five similar intersections (three with countdown signals and two without countdown signals) in Shanghai, this research evaluated the impact of countdown signals on intersection safety and efficiency. Three categories of data were collected using a video detection system and questionnaire methods - crossing behaviour data (e.g. pedestrian speed and number of pedestrians obeying signals), questionnaire data (e.g. understanding of count-down signals) and crosswalk-related data (e.g. cycle length and length of the crosswalk). Statistical analysis results based on t-tests and analysis of variance revealed that the impacts of countdown signals on older and younger people are different in terms of compliance ratio and successful crossing ratio. Countdown signals also decreases the perception-reaction time and significantly improves crossing speed, especially at the end of clearance time. The questionnaire results showed that understanding of the real meaning of pedestrian clearance time is not changed by the installation of countdown signals. Despite its effectiveness in facilitating the pedestrian decision-making process, the installation of countdown signals may adversely increase the possibility of collisions with unexpected right-turning vehicles, crossing vehicles or bicycles due to the significantly increased speeds of pedestrians at the end of clearance time.
... There is a tremendous added value in the PCT for the pedestrian: it gives him more information before he decides on making a crossing. For wide intersections, the PCT has an undeniable safety benefit (as mentioned in many studies, like Markowitz et al, 2006). Without it, the pedestrian has no indication regarding the amount of time he has to complete the crossing, either before engaging or during the crossing. ...
Article
Busy intersections have been regulated by traffic lights for more than a century. In 1868, downtown London had so much horse and wagon traffic that a British railroad signal engineer designed the first traffic semaphore to regulate movements near the Parliament. The device was indeed the first traffic "light", as lenses in the semaphores where lighted by gas lanterns at night. Besides traffic regulation, one of the goals behind the creation of the device was the protection of pedestrians. Various manually-operated devices appeared in the following decades, usually manned by policemen whose whistle took care of the clearance interval. In the golden years of the horseless carriage, rapidly increasing traffic required a new way to regulate movements. The first electric traffic lights appeared in 1912, but only in 1914 did the first traffic light controller made in way to Ohio streets. The blueprint for modern traffic signals, the three-color signal head, bowed in 1920.
... within three years, and then within seven years of implementation; and, - [7][8][9][10][11][12][13][14][15][16][17][18][19][20] Year Strategies: formal evaluations should be conducted every three years. ...
... Traffic engineers' intuition is often sufficient for treatment of problems related to common problems of black spots of a certain type. Successful examples include the installation of the several hundred countdown signals at pedestrian crossings in San Francisco that reduced the number of pedestrian injuries caused by crashes with vehicles by 52% (Markowitz et al., 2006), and the system for detecting pedestrians approaching a crosswalk zone that warns drivers of pedestrian presence (Hakkert et al., 2002). In both examples, the effectiveness of the safety measures was evaluated by comparing the accident rates before and after the implementation of safety measures. ...
Article
Data on traffic accidents clearly points to road black spots, where the accident rate is always high. However, road safety research is still far from understanding why this particular place on a road is risky. The reason is the lack of sufficient knowledge on how pedestrians and drivers interact when facing a potentially dangerous traffic situation, and the lack of an integrated framework, that relates the data on human behavior to real-world traffic situations. We attempt to tackle this problem by developing SAFEPED, a multi-agent microscopic 3-D simulation of vehicle and pedestrian dynamics at a black spot. SAFEPED is a test platform for evaluating experimentally estimated drivers’ and pedestrians’ behavioral rules, and estimating accident risks in different traffic situations. It aims to analyze the design of existing and future black spots and to assess alternative architectural and environmental solutions in order to identify maximally efficient safety countermeasures.
... Finally, important outcomes derived from "before" and "after" studies, regarding the reduction in injury collisions. Pilot installations showed a 52-percent reduction due to PCCST systems (Markowitz, Sciortino, Fleck, & Yee, 2006), whereas Keegan and O'Mahony (2003) observed an 11% reduction of people who starting to cross the intersection during the red man. ...
Article
The study presents the evaluation of the efficiency of crossing countdown timers (PCCST) for pedestrians at signalized pedestrian crossings. It is based on observations of the behaviour of pedestrians and motorists at an intersection, located in a major city in Greece. A series of surveys and pedestrian interviews were conducted to evaluate the behaviour of pedestrians and motorists. Data statistical analysis indicated that the countdown signals are able to provide pedestrians with valuable information that enhances the safety level as far as crossing of the intersection is concerned. The pedestrian interviews revealed that most of them properly interpreted the meaning of the “green man” signal and the countdown clock. Finally, it is considered desirable by the pedestrians to install pedestrian countdown signals in other signalized pedestrian crossings as well.
... This finding however, was based on the analysis of nine high collision intersections; effect size may have been partly due to a regression to the mean effect. 11 An estimated baseline collision history was considered in the present study; and the differences in intersections with high versus low collision rates were accounted for in the analysis. Pulugurtha et al 12 reported a decline in collision rate and found PCSs are most effective at high crash and high volume intersections. ...
Article
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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.
... Consequently, many studies found PCT to be very effective in increasing pedestrian crossing speed (Hediye et al., 2014, York et al., 2011. Few studies observed that the time remaining for each of these phases helped in increasing the pedestrian safety at signalized intersections (Cleaver et al., 2011, York et al., 2011, Markowitz et al., 2006, Keegan and O'Mahony, 2003. Another study by Kapoor and Magesan (2014) showed that PCT has different effects on different road users. ...
Technical Report
Objectives as stated in the project report: i. To study the approach speed of different kinds of vehicles entering the intersection area during green phase, and thereby to study the effect of countdown signal timers on speed characteristics of approaching vehicles (50th percentile speed, 85th percentile speed, etc.) ii. To observe the effect of countdown timers on saturation headways and start-up lost time iii. To examine the effect of countdown timer on driver behaviour, particularly driver decisions on whether to stop or proceed at the onset of transition phase and rate of red light violations iv. To assess the perceptions of drivers of various types of motorised and non-motorised vehicles, as well as pedestrians as they relate to countdown signal timers
... Finally, results also suggest that it could be of positive value installing the countdown timer at intersections indicating the next boat departure time for passengers and bicyclists to gauge the wait, as Markowitz et al. (2006) reported. Warning sign and pavement marking should be allocated before approaching the intersection to inform speed limit and notice of passenger and bicyclist crosswalk,… etc. ...
Article
Pedestrian- and cyclist- involved crashes at intersections remain a major concern in China due to high ratio of fatal injuries and fatalities. This paper develops the random parameters negative binominal model to determine the relationship between potential contributory factors and crash frequency involving pedestrians and bicyclists at intersection locations and identify the significant risk factors, using 4,066 observations over the period 2008–2013 from Zhengzhou and Xi’an, China. The use of random parameters’ model is utilized as a mean to accommodate possible unobserved heterogeneity across intersections, and a maximum likelihood method with Halton draws is proposed to estimate the maximum likelihood of random parameters. Additionally, marginal effects are applied to assess the impact of expected instantaneous change of each dependent variable on crash frequency while keeping all the other covariates constant. Among many potential factors, passenger countdown timer, passenger push button, number of left turn lanes, left turn traffic, ratio of major direction AADT to minor direction AADT and driver’s disregarding ‘give-way’ sign behavior,… etc. have significant association with passenger crash frequency, but a less impact on bicyclist crashes. The findings of current study could provide an important insight into traffic safety improvement projects for passengers and bicyclists at both planning and operational levels.
... Consequently, many studies found PCT to be very effective in increasing pedestrian crossing speed [21,22]. Few studies observed that the time remaining for each of these phases helped in increasing the pedestrian safety at signalized intersections [14,[22][23][24]. Another study by Kapoor and Magesan [25] showed that PCT has different effects on different road users. ...
Article
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Installations of signal countdown timers (SCTs) adjacent to the traffic signal heads are on the rise at several intersection locations in India. These SCTs provide information related to the time left for a particular signal phase and thus expected to help the driver take better decision. But no scientific studies were carried out before their installations at intersection locations. Pedestrian countdown timers (PCTs), which work on the same principle as SCTs found to be effective in terms of reducing pedestrian violations, pedestrian-vehicle conflicts as they provide information about the time left for a particular phase. These PCTs are becoming common at urban intersections in Indian cities, but not in very large numbers as their installation will require an additional infrastructural cost. In order to assess whether the SCTs themselves can facilitate the pedestrian movement at signalized intersections or not, the present study attempts to observe their effect on pedestrian movements at zebra crossing locations. When countdown timers were present, a higher percent of the cycles were observed to have some sort of red light violations (RLVs) as compared to the situation when the timer was absence. Average red light violations per red light cycle were found to be 3.2 and 2 RLV / RLV cycle in the presence and absence of signal countdown timers, respectively at intersection 1. The similar trend observed in intersection 2 (6.7 and 2.5 RLV / RLV cycle in the presence and absence of signal countdown timers respectively). SCTs did not have any effect on pedestrian waiting time on curb or pedestrian speed during crossing. These digital timers increased pedestrian violations. In the absence of SCT, less number of pedestrians was observed to cross the road during green and yellow phase, whereas higher number of pedestrian crossings was found during the initial portion of red phase. Overall, it was observed that rampant installation of these SCTs at major urban signalized intersections without conducting extensive studies would detrimentally affect the pedestrian movements making the crossing process complex and unsafe.
... Recent studies use Geographic Information Systems (GIS) methodologies for understanding the spatial patterns of accidents (Pulugurtha et al., 2007). Most of the statistical findings, which guide authorities in coordinating countermeasures, were motivated by the need to examine the effectiveness of road safety or vehicle engineering improvements; and compared the safety state before and after making modifications (Hakkert et al., 2002;Markowitz et al., 2006). However, statistical data is inefficient for determining accident causation, since the complex chain of events that preceded an accident is rarely recorded in detail that is sufficient to draw conclusions (Archer, 2005). ...
Article
Analysis of accidents that involve vehicles and pedestrians requires accurate reproduction of the dynamics of the vehicles and pedestrians immediately prior to and during the accident. In many cases, only centimeters and milliseconds separate survival from disaster, particularly when high-speed aggressive drivers and careless pedestrians are involved. In this paper we present a methodology for analyzing the dynamic interaction between drivers in conflict scenarios with pedestrians. We assess the safety of a traffic location’s environment with a highresolution, spatially explicit, dynamic agent-based simulation model – SAFEPED. Based on the resulting data, Range-Range Rate (R-RR) graphs are generated. These graphs provide compact, simple, and objective presentation of the dynamic interaction between vehicles and pedestrians. Significant traffic risk indicators such as Time-To-Collision, acceleration/deceleration rates, and minimal distances between vehicles and pedestrians are easily extracted from the R-RR graphs. These indicators can provide insights on particular traffic scenarios and can assist road planners and developers of traffic safety measures in understanding the dynamic behavior of drivers and pedestrians before and during a conflict scenario
... It is reaffirmed in this study that the installation of GMCD increases both crossing velocity, especially for late starters. Moreover, it is consistent with some existing studies conducted in the US and Serbia that installation of GMCD reduces the proportion of late starters that start to cross during last few seconds of green-man signal [23,24]. However, the latter finding is contrary to some existing studies conducted in the US and Australia [9,25]. ...
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Safety effects of Green-Man Countdown Device (GMCD) at signalized pedestrian crosswalks are evaluated. Pedestrian behavior at GMCD and non-GMCD crosswalks is observed and analyzed. A microsimulation model is developed based on field observations to estimate safety performance. Simulation outputs allow analysts to assess the impacts of GMCD at various conditions with different geometric layout, traffic and pedestrian volumes, and the green time. According to simulation results, it is found that the safety impact of GMCD is affected by traffic condition as well as different time duration within green-man signal phase. In general, GMCD increases average walking velocity, especially during the last few seconds. The installation of GMCD improves safety performance generally, especially at more crowded crossings. Conflict severity is increased during last 10 s after GMCD installation. Findings from this study suggest that the current practice, which is to install GMCD at more crowded crosswalks or near the school zone, is effective. Moreover, at crosswalks with GMCD, longer all red signal phase is suggested to improve pedestrian safety during intergreen period.
... Their findings revealed that there has been a statistically insignificant decrease in vehicle-pedestrian crashes but there was a significant decrease in all crashes (pedestrian and vehicle involvement). Moreover, studies conducted by Markowitz et al, 2006, considered a 21-month before and after study period at 14 signalized intersections. Their study results showed that, pedestrian countdown signals reduce pedestrian crashes and injuries. ...
Technical Report
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In 2004, the Michigan Department of Transportation (MDOT) began a comprehensive program to implement engineering countermeasures to address the needs of older drivers. The countermeasures included the use of Clearview Font on Guide Signs (freeway and non-freeway), installation of Box Span signals, installation of pedestrian countdown signals, use of Fluorescent Yellow Sheeting on warning signs, and use of arrow-per-lane on guide signs. This study aimed at evaluating safety benefits of the selected countermeasures. Evaluation was performed through a perception survey of Michigan drivers and analysis of crash data. Safety Performance Functions (SPF) for these improvements were developed as part of the study. Crash Modification Factors (CMF) for each countermeasure were developed through the before-after analysis of crash data. Finally, the benefit cost analysis of each countermeasure was performed and is documented in this report.
... Furthermore, as previously noted, males are more likely to engage in violations when crossing than their female counterparts. Additionally, age influences the probability associated with violation, where young adults are associated with the greatest likelihood of violation or hazardous violation, thereby corroborating the extant literature regarding higher prevalence among young adults (28), males (20), and smaller groups (22). ...
... These countdown signals show the amount of time remaining in the clearance interval (FDW). A number of studies have reported a reduction in pedestrian-motor vehicle conflicts and improved pedestrian safety as a result of the pedestrian countdown timer installation (Huang and Zegeer, 2000;Markowitz et al., 2006;Chen et al., 2015;Lambrianidou et al., 2013;Schmitz, 2011;Scott et al., 2012;Vasudevan et al., 2011;Eccles et al., 2004). The pedestrian countdown timers were also found to improve driver safety (Kwigizile et al., 2015;Kitali et al., 2018). ...
Technical Report
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Three primary tasks were completed to accomplish these objectives: 1) a literature review, 2) an inventory of existing bicycle signal installations, and 3) interviews with key agency staff. The relevant literature was identified by searching TRID (Transport Research International Documentation) for the appropriate keywords. This literature was supplemented with MUTCD Request to Experiment (RTE) filings (which are approved experiments with traffic control devices not in the MUTCD), and final evaluation reports submitted to FHWA. Grey literature, including evaluation reports by public agencies, blog posts, and popular press stories, were also reviewed. The locations of bicycle signals were identified from an online survey and an existing list maintained by the bicycle technical committee of the National Committee on Uniform Traffic Control Devices. For the 511 intersections where the installation of a bicycle signal was verified, the research team collected data on year of installation, number of bicycle faces, mounting heights, distance from the stop line, use of arrows, lens diameter, use of colored housing or backplates, presence of visibility restricted louvers and a few other data elements, primarily by reviewing Google Streetview images. Structured interviews were conducted with key staff at 21 agencies, which included six state DOTs, 14 cities, and one county to explore their experiences and gather their input on research needs. Finally, the synthesis of the results from the literature review, inventory and interviews identified three research needs in the road user’s understanding of bicycle symbols in the signal face.
... However, Chiou and Chang (2010) further concluded that red signal countdown did not improve intersection after their installation. Four other studies (Schattler et al., 2007(Schattler et al., , 2015Markowitz et al., 2006;Singer et al., 2015) showed that PCSs encourage pedestrian compliance, reduce pedestrian injuries, and are preferred by pedestrians. ...
Article
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Objective: This study evaluated the safety impacts of PCSs with and without pushbuttons based on pedestrian crashes and pedestrian injuries in Michigan. Methodology: This study used ten years of intersection data: five years before PCSs were installed and five years after they were installed, along with a comparison group, to evaluate the crash impacts of PCSs: at 107 intersections the PCS had a pushbutton and at 96 it did not. At these intersections, and at their comparison sites (where no PCS was installed), crash data (from 2004–2016) were examined, along with traffic and geometric characteristics, population, education and poverty levels data. Results: Intersections where PCSs with pushbuttons have been installed showed a 29 percent reduction in total pedestrian crashes and a 30 percent reduction in fatal/injury pedestrian crashes. Further, when considering only pedestrians age 65 and below, these respective reductions are 33 and 35 percent. Intersections with PCSs but without pushbuttons did not show any significant change in any type of pedestrian crash. Conclusions: Although the Manual of Uniform Traffic Control Devices (FHWA, 2009) requires the use of PCSs at new traffic signal installations, this study suggests a safety benefit of installing PCSs with pushbutton at signals where a PCS without a pushbutton is present.
Article
Pedestrian violations of traffic signals and dangerous crossings at intersections are common. The objective of this study is to determine the impact of pedestrian waiting time at an intersection on the proportion and type of pedestrian violations and dangerous crossings. The amount of waiting depends on signal phasing, time of arrival, and the presence of a pedestrian signal. Thirteen intersections with similar geometry and traffic conditions but different maximum waiting times, seven of which had a pedestrian signal, were observed over at least 2 h to collect crossing information. Data was collected manually for the main analysis and complementary video data was used for validation. Several factors were identified as having an impact on the proportion of pedestrian violations. In accordance with the literature, age, sex, group size, pedestrian flow and pedestrian signals are associated to pedestrian violations. In addition, other factors were identified in this research, such as maximum waiting time (red phase). It was also determined that an intersection clearing time had an impact on violations and on the proportion of dangerous crossings committed. Also, pedestrians’ speeds depended on the type of crossing. The results underline the importance of providing pedestrian signals including countdown displays, which is significantly and negatively linked to dangerous violations and crossings. The results also highlight the importance of pedestrian maximum waiting time as well as clearing time. When designing cycle and phase lengths, particular attention should be paid to pedestrian waiting times that are positively correlated to violations. Minimizing waiting times for pedestrians is expected to reduce dangerous pedestrian behaviors at signalized intersections.
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Two-stage crossing with a median refuge island is commonly installed at the busy urban signalized intersections. To accommodate for the high traffic flow in different directions, split phasing is often applied for pedestrians’ right of way of the two crossing stages. Previous studies mainly focus on the time delay, capacity and operation efficiency of two-stage crossings. It is rare that safety of two-stage crossings is investigated. Crossing behaviors and propensities of red light running at the two crossing stages (i.e. from the curbside to a central island, and then to another side of the road) are different from that of single stage crossing. Also, there could be interferences in the crossing behaviors and situational features between the two stages. This study aims to identify the personal characteristics, traffic attributes and environmental factors that affect the red light running propensities of pedestrians at the two-stage crossings, based on the video observation surveys at six urban signal intersections in Hong Kong. Random parameter logit regression approach is applied to measure the association between possible factors and propensities of red light running of pedestrians, with which the effect of unobserved heterogeneity is accounted. Results indicate that, other than the pedestrians’ characteristics, pedestrian signal of the second stage, maximum waiting time and traffic flow significantly affect the propensity of red light running in the first stage. Also, there are significant interaction effects between pedestrians’ characteristics and situational features on the propensity. On the other hand, pedestrians’ waiting time before crossing the first stage significantly affects the propensity of red light running in the second stage. Findings are indicative to the design of pedestrian crossing, signal time plan and effective enforcement and education strategies that can deter against the red light running behaviors of pedestrians. Therefore, safety of two-stage signalized crossings can be enhanced.
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Pedestrian is vulnerable to mortality and severe injury in road crashes. Red light running violation of pedestrians is one of the leading causes to the crashes at signalized intersections, at which the crash involvement rates of pedestrians are high. Therefore, it is important to identify the factors that affect the propensity of red light running of pedestrian. In this study, effects of both personal factors (pedestrians’ demographics and behavior) and environmental factors (presence and behavior of other pedestrians, signal time, and traffic condition) on the individual decision of red light running violation are examined, using the video observation surveys at the signalized crossings that are prone to pedestrian-vehicle crashes and have moderate pedestrian and vehicular traffic volumes in the urban area. Crossing behaviors of 6320 pedestrians are captured. Results of a random parameter logit model indicate that pedestrian gender, age, number of lanes, presence of a companion, number of pedestrians around, presence of other violators in the same cycle, time to green, red time, traffic volume, and percentage of heavy vehicles all affect the propensity of red light running violation of pedestrians. Also, there are significant interaction effects by pedestrian’s gender and age, presence of other violators, with a companion, and traffic volume on the propensity. Findings are indicative to the development of effective engineering, enforcement and educational initiatives combating the red light running violation behavior of pedestrians. Therefore, pedestrian safety level at the signalized intersections can be enhanced.
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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.
Conference Paper
According to the Manual on Uniform Traffic Control Devices (MUTCD), Countdown Pedestrian Signals (CPS) shall only be displayed during the clearance interval (FLASHING DON'T WALK - FDW) of pedestrian signals. The primary purpose of this CPS display is to inform pedestrians of the remaining time for crossing a road controlled by the signal, to discourage them from starting, and to inform those who are already on the way of the remaining time before the beginning of the DON'T WALK (DW) interval. The general literature on CPS is conclusive that CPS is better understood than the conventional pedestrian signals. In the District of Columbia the CPS display starts at the onset of the Steady WALK (SW) interval and continues through the FDW interval. It is not certain whether this CPS display has any advantage over the standard display as prescribed by the MUTCD. In this research a comparative field study of both types of countdown displays at twenty-five (25) intersections in the District of Columbia was conducted. The results of the evaluation showed that at the majority of the intersections studied, there were no statistically significant differences in pedestrian crossing behaviors (using 5% significance level) due to the type of CPS display.
Article
Introduction Pedestrian countdown signals (PCSs) are specifically designed to improve pedestrian safety at intersections. However, the cost of retrofitting an existing intersection with a PCS, or the cost of including a PCS in a new intersection, may discourage PCS use at locations with a low pedestrian demand. Surprisingly, however, these devices appear to have positive safety benefits for a demographic group that is poised to increase by 20 percent nationally over the next two decades (2020–2040): older population age 65 years and above. Between 2012 and 2016, the number of licensed older drivers (65 + years) increased by 16 percent (NHTSA, 2013). Using the state of Michigan as a case study, this paper reports on the safety impacts of PCSs for motorists age 65 + years. Methods The study used ten years of crash data (five years before and 5 years after PCSs installation) from 93 intersections with PCS (treated sites) and a comparison group of 97 intersections without countdown timers (but with pedestrian signals). A before-after with comparison group methodology, crash proportions and cost benefit analysis were used to conduct the PCS evaluation on senior motorists. Results The study indicated that the inclusion of PCSs significantly reduced total (all severity) and injury only crashes for drivers aged 65 and above by 18 and 29 percent (p < 0.05) respectively. Monetization of crash impacts also suggests that inclusion of PCSs when installing a pedestrian signal yields a benefit-cost ratio ranging from 181 to 604 depending on the service life of the device. The focus on motorists aged 65 + is noteworthy, as PCSs did not necessarily have a statistically significant impact when motorists of all age groups are considered. Conclusion Localities may wish to consider PCSs when there are concerns about senior motorist crashes at intersections since they also benefit from PCSs. Because PCSs may be installed at locations with other safety treatments, a synthesis of other locations’ experiences with PCSs would complement the results of this study.
Article
Pedestrians represent the most vulnerable category of participants in traffic. More and more complex traffic conditions in cities across Europe, and therefore BiH, threaten traffic to become a challenge for pedestrians, and pedestrians often experience traffic as a challenge. Studies of behavior of pedestrians at signalized pedestrian crossings conclude that there is a high level of insecurity and a high percentage of unsafe crossings by pedestrians. Timers that add pedestrian signals indicate the length of the red light, the remaining time to the beginning of the green light for the safe crossing of pedestrians across the street. This paper analyzes the effect of the countdown pedestrian signals - CPSs in different weather conditions, ie the comparison of pedestrian behavior (switching to red light) without CPSs and with CPSs in different weather conditions (sun, snow, rain, no precipitation with a temperature of 0 degrees) was performed. The paper analyzes a traffic light pedestrian crossing over the road that consists of four traffic lanes in Banja Luka, BiH.
Article
Literature has suggested that angle/rear-end collisions would arise from the reality that motorists and motorcyclists tended to accelerate aggressively in response to the remaining seconds of green signal countdown device (GSCD). One safety concern, while GSCD has gradually been removed for safety in Taiwan, is pedestrian green signal countdown device (PGSCD) that is used by approaching motorists and motorcyclists that may adopt the information to travel aggressively – an unintended consequence that is detrimental to safety. Research has reported that there appeared no negative effect of PGSCD on motorist behaviours but the effect on motorcyclists’ behaviours has been rarely investigated. Using video/speed cameras, the current research investigates motorcyclists’ RLV (red-light violation) behaviours. The descriptive analyses indicate that the percentage of RLV at PGSCD intersection is higher than that at typical intersection, and the violating motorcycles appear to have higher travelling speeds at PGSCD intersection. Several interaction terms were examined with the binary logit framework, and the results reveal that several factors are associated with RLV, notably male/young riders, moped/large motorcycle users, higher approaching speeds of motorcycles, those with tropical helmets, and lower traffic volume. Similar determinants of early-start behaviours (for those waiting at reds and could view the PGSCDs for the crossing pedestrians at the same time) were identified. Implications of the research findings, the concluding remarks, and recommendations for future research are finally provided.
Article
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In this paper we proposed method for assessing pedestrian risk at the signalized pedestrian crossing equipped with counter. Results showed that 17.5% of pedestrians were at high risk and male pedestrians are more often in dangerous situation (20.4%) than female pedestrians (14.4%). About 3% of all examined pedestrians created conflict situations, more frequently in first 5 seconds and last 5 seconds of red light phase (79.7% of all offenders), but the risk that pedestrians will create a conflict situation were higher in other time of red light phase. Analysis of pedestrians’ behavior at pedestrian crossings equipped with countdown display could point to potentially safety problems for pedestrians and those analysis could give direction for proposing and implementing adequate countermeasures. Also, numerically defined pedestrian accident risk could assess road safety level for pedestrians and show accident occurrence probability.
Article
This study evaluated the effect of visual pedestrian signal displays on the ability of persons with reduced visual acuity to accurately and confidently identify the pedestrian interval. While watching video clips of actual intersections presented on a 42-in. monitor under simulated visual impairment, participants attempted to determine the pedestrian interval ("Walk," flashing "Don't Walk," or steady "Don't Walk") and provided confidence ratings for each judgment. Participants in Experiment 1 experienced simulated acuities of 20/70, 20/100, and 20/200; participants in Experiment 2 experienced approximate acuities of 20/20, 20/50, and 20/300. The study made a critical comparison of two methods of signaling the pedestrian change interval (i.e., flashing "Don't Walk"): (a) simultaneous presentation of a countdown and a flashing upraised hand symbol and (b) a countdown-only display without the flashing upraised hand. With the exception of performance in the 20/300 vision category, participants' accuracy on the interval discrimination task was, overall, rather high. However, under simulated visual impairment of 20/70 or worse, participants' success in correctly determining the pedestrian interval was, on average, 21.5 percentage points lower for the countdown display presented without the flashing upraised hand than for the countdown display with the upraised hand. The participants' average reported confidence in their judgment was also lower for the countdown-only condition, and their interval judgment response times also showed a negative effect of the countdown-only display. Implications of the study findings with regard to visual impairment and signal displays for the pedestrian change interval are discussed.
Article
Describe age-based urban pedestrian versus auto crash characteristics and identify crash characteristics associated with injury severity. Secondary analysis of the 2004-2010 National Highway and Traffic Safety Administration database for Illinois. All persons in Chicago crashes with age data who were listed as pedestrians (n=7175 child age ≤19 yo, n=16,398 adult age ≥20 yo) were included. Incidence and crash characteristics were analyzed by age groups and year. Main outcome measures were incidence, crash setting, and injury severity. Multivariate logistic regression analysis was performed to estimate injury severity by crash characteristics. Overall incidence was higher for child (146.6 per 100,000) versus adult (117.3 per 100,000) pedestrians but case fatality rate was lower (0.7% for children, 1.7% for adults). Child but not adult pedestrian injury incidence declined over time (trend test p<0.0001 for <5 yo, 5-9 yo, and 10-14 yo; p<0.05 for 15-19 yo, p=0.96 for ≥20 yo). Most crashes for both children and adults took place during optimal driving conditions. Injuries were more frequent during warmer months for younger age groups compared to older (χ(2)p<0.001). Midblock crashes increased as age decreased (p<0.0001 for trend). Most crashes occurred at sites with sub-optimal traffic controls but varied by age (p<0.0001 for trend). Crashes were more likely to be during daylight on dry roads in clear weather conditions for younger age groups compared to older (χ(2)p<0.001). Daylight was associated with less severe injury (child OR 0.93, 95% CI 0.87-0.98; adult OR 0.90, 95% CI 0.87-0.93). The incidence of urban pedestrian crashes declined over time for child subgroups but not for adults. The setting of pedestrian crashes in Chicago today varies by age but is similar to that seen in other urban locales previously. Injuries for all age groups tend to be less severe during daylight conditions. Age-based prevention efforts may prove beneficial. Copyright © 2015 Elsevier Ltd. All rights reserved.
Chapter
This chapter assists practicing engineers in considering road user limitations, of which there are many, in design and, in particular, in considering the roadways from the perspective of the inexperienced, the older, and the unfamiliar user. The first section addresses basic issues, and provides an understanding of human characteristics and limitations, especially in regard to visual search, processing of information, and the importance of expectations in determining behavior. The second considers current practice with respect to traffic control device (TCD) and roadway design that facilitates error-free performance. Road design features are considered from the perspective of the related driving task, likely road user errors, and appropriate and effective countermeasures to address these errors. The third section deals with case studies, and the fourth section with emerging trends in the area of human factors. Methods of influencing driver speed choice are also discussed.
Preprint
Abstract. What is the relationship between road safety research and the practice by which the road infrastructure is built and operated? The question is seldom asked. I discuss the complexities of the research-practice symbiosis in the light of two historical anecdotes. These allow me to point out twelve issues of concern. My general conclusion is that the relationship as it evolved over time is unpremeditated and occasionally dysfunctional. Findings can be easily disregarded and questionable results given a ring of consensual truth. Practice based on such knowledge cannot be evidence-based. In the interest of road-user safety it is time to endow the research-practice relationship with a clear and purposeful structure.
Article
In 2010 the Transportation Association of Canada began the 2-year process of updating the 1998 pedestrian crossing control manual. The resulting document, the Pedestrian Crossing Control Guide, is expected to promote uniformity across the country with respect to the approach used in the provision of pedestrian crossing control. This standardization is done through the development of a decision support tool to assist in the decision-making process when the need for pedestrian crossing control is established and in identification of the type of crossing control to use for the location's characteristics. The development of the new Pedestrian Crossing Control Guide for Canada is discussed, and findings of the research that led to its development are presented. The findings fall into two areas: existing Canadian and international pedestrian crossing control practices and safety performance of different pedestrian crossing control devices. Principal conclusions from this research are (a) international practice is changing toward providing guidance rather than formal, numerical warranting procedures in the decision-making process for the provision of pedestrian crossing control; (b) there are pedestrian crossing control treatments for which there is no available literature regarding safety performance, and the available literature for other treatments lacks rigorous safety evaluations; and (c) further research is needed regarding the safety performance of pedestrian crossing control devices, particularly in the areas of understanding pedestrian collisions and developing accident prediction models.
Article
Pedestrian signals are viable traffic control devices that help pedestrians to cross safely at intersections. Although the literature is extensive when dealing with pedestrian signals design and operations, few studies have focused on the potential safety benefits of installing pedestrian signals at intersections. Most of these studies employed simple before-after (BA) safety evaluation techniques which suffer from methodological and statistical issues. Recent advances in safety evaluation research advocate the use of crash modification functions (CMFunctions) to represent the safety effectiveness of treatments. Unlike crash modification factors (CMFs) that are represented as single values, CMFunctions account for variable treatment location characteristics (heterogeneity). Therefore, the main objective of this study was to quantify the safety impact of installing pedestrian signals at signalized intersections by developing CMFunctions within an observational BA study. The use of observational BA framework to develop the CMFunctions avoids the cross-sectional approach where the functions are derived based on a single time period and no actual treatment intervention. Treatment sites heterogeneity was incorporated into CMFunctions using fixed-effects and random-effects regression models. In addition to heterogeneity, the paper also advocates the use of CMFunctions with a time variable to acknowledge that the safety treatment (intervention) effects do not occur instantaneously but are spread over future time. This is achieved using non-linear intervention (Koyck) models, developed within a hierarchical full Bayes context. The results demonstrated the importance of considering treatment sites heterogeneity (i.e., different circulating volumes and area type among treated locations) and time trends when developing CMFunctions for pedestrian signal improvement.
Article
Pedestrian crashes are somewhat unique because the responsibility for them is not equally shared between drivers and pedestrians. In the case of pedestrian crashes, there are several reasons the driver should be assigned a higher proportion of the degree of responsibility. First, drivers must meet minimum standards in regard to knowledge, vision, age, and demonstrated skill level that cannot be legally required of walking. Second, it is often said that driving is a privilege and not a right. One cannot say the same for walking. Although it is possible to remove an individual's driving permit, it would be a gross violation of human rights to deprive someone of the right to walk. Third, pedestrians include individuals who do not have the same physical or cognitive skills as drivers. For example, all children and some seniors do not meet the minimum standards required to operate a motor vehicle. Both these groups have been demonstrated to be deficient in judging gaps. Persons with physical challenges such as the blind pedestrians or persons with mental challenges also have a right to mobility. It cannot reasonably be asserted that a blind pedestrian has the same level of responsibility to avoid a crash as a licensed driver. Because pedestrians are vulnerable road users, it is critical that methods should be developed to improve the safety of walking. One way to improve the safety of pedestrians is to teach drivers and pedestrians to follow the rules of the road.
Article
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The paper offers the analysis of pedestrian behavior at a signalized pedestrian crossing equipped with a pedestrian refuge island, depending on whether a pedestrian countdown display is installed or not. The cameras recorded pedestrians crossing the roadway with a refuge island, in a zone with two similar pedestrian crossings equipped with pedestrian refuge islands, in the area of the city of Belgrade (Serbia). A countdown signal for pedestrians installed at one of the pedestrian crossings showed the remaining time of the red light, while the second pedestrian crossing was not equipped with a countdown display. Video recordings, recorded time of the commencement of crossing the Stage 1 and 2 of the roadway (first and second roadway) were reviewed and analyzed in detail. The data on pedestrians, vehicles and times are entered into the tables specially prepared for this survey. The aim of the work was to observe and compare the models of behavior of a certain category of pedestrians at Stage 1 (to the refuge island) and Stage 2 (from the refuge island) of the pedestrian crossing, without and with a pedestrian countdown display.
Article
The effects of pedestrian countdown signals on speeds of approaching vehicles as a function of the distance of the vehicle upstream of the intersection and the signal display are reported here. The analyses used mean speeds of vehicles on two segments immediately upstream of the stop bar and also during different indications of the pedestrian signal head (pedestrian "Walk" and pedestrian flashing "Don't Walk" signal with the time remaining in seconds to cross the street for the following intervals: greater than 15s, 15s to 10s, 10s to 5s, and less than 5s). Appropriate tests were performed to determine the statistical significance of the differences in observed mean speeds for each of these scenarios. Vehicle speeds were greater on the segment closer to the intersection than on the segment farther away. The speeds were also greater during the pedestrian countdown timer and flashing "Don't Walk" displays on the pedestrian signal head than when the pedestrian "Walk" signal and the countdown timer were displayed. All results were statistically significant at a 95% level of confidence except one, which had a 93% level of confidence. Results do not indicate that speeds are affected by the actual numeric displays on the countdown timer.
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