Pedestrian safety at traffic signals: A study carried out with the help of a traffic conflicts technique

doi:10.1016/0001-4575(89)90004-3

Accident Analysis & Prevention

Volume 21, Issue 5, October 1989, Pages 435-444

https://doi.org/10.1016/0001-4575(89)90004-3 Get rights and content

Abstract

Most pedestrian accidents in built-up areas occur at intersections. Even after signalization the number of accidents involving pedestrians often remains high. After reviewing the published evidence, this paper describes how the Traffic Conflicts Techniques has been used to examine the risk to pedestrians at 120 intersections. The principal results indicate that signalization of a high-speed intersection (mean speed above 30 $km h$ in at least one arm) reduces pedestrian risk to approximately half. If mean speed in every arm is below 30 $km h$ signalization also reduces pedestrian risk, as long as most vehicles are not turning. Another finding from these studies was that a crosswalk should be located less than two meters from the intersection to optimize pedestrian safety. The conflict studies as well as analyses of accident data show that one should examine separately accidents between turning vehicles and “green-walking” pedestrians and accidents involving pedestrians walking against red light. The effect of an exclusive pedestrian signal phase (scramble) was tested at three sites and proved to be very safety-beneficial in a small town, while in Stockholm it did not prove effective because of a high percentage of red-walkers. Vehicle delay, as well as pedestrian delay, increased at all three sites. Data collected at 152 crosswalks has been used to estimate the parameters of a multivariate model of the frequency of “red-walking.” The size of the town and traffic volumes appear to be the major factors influencing this frequency. Additional insight has been obtained from personal interviews of 450 persons. These indicate that shorter waiting times and police enforcement are considered the most efficient measures to reduce the the frequency of red-walking.

References (14)

M. Short et al.
Effects of traffic signal installation on accidents
Accid. Anal. Prev.
(1982)
K.L. Bång
Signalreglering och trafiksäkerhet, en före- efterstudie
Stockholms gatukontor, rapport nr. 14
(1969)
M.H. Cameron et al.
Pedestrian accidents and exposure in Australia
P. Gårder
Theory for strong validation, application to Swedish results
C.A. Hydén
Traffic-conflicts technique for determining risk
C. Hydén
The development of a method for traffic safety evaluation—the Swedish traffic conflicts technique
International Committee on Traffic Conflicts Techniques (ICTCT)

There are more references available in the full text version of this article.

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Citation Excerpt :
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Pedestrian protection is an important component of road safety. Intersections are dangerous locations for pedestrians with mixed traffic. This paper aims to predict potential traffic conflicts between pedestrians and vehicles at signalized intersections. Using detection and tracking techniques in computer vision, pedestrians’ and vehicles’ features are extracted from video data. An LSTM (Long Short-term Memory) neural network is proposed to predict the pedestrian-vehicle conflicts 2 s ahead. The established model reaches an accuracy of 88.5 % at one signalized intersection. It is further tested at a new intersection, reaching the accuracy of 84.9 %, while the new data merely takes up 30 % of the training data set. This indicates that the proposed model is promising to be implemented at different locations. Moreover, the proposed model can also be applied to develop collision warning systems under the Connected Vehicles’ environment.
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Signalized intersections with marked crosswalks enhance pedestrian safety by providing the designated right of way to pedestrians. However, a significant number of pedestrian crashes occur at signalized intersections, which may predominantly be due to pedestrians’ violation behaviors. Therefore, it is worthwhile to examine how pedestrian risk and signal violation are associated. For this purpose, pedestrians’ crossing behavior, and perception data have been collected from 55 signalized junctions in Kolkata, India, and a mathematical relationship is developed between the share of pedestrian signal violation and the frequency of fatal pedestrian crashes. The model outcome indicates that there is a significant and positive association between these two variables. Subsequently, with the help of “beta regression model” it is identified that absence of pavement marking, traffic cycle length, inadequate sight distance, on-street parking, a high share of pedestrian carrying overhead loads, pedestrian’s intended mode of transport after crossing, and pedestrian’s sociodemographic characteristics significantly influence the share of pedestrian signal violation behavior. The study finding indicates that while improvement in the design of the built environment and signal settings to increase pedestrians’ convenience and confidence are must, and there is a crucial need to integrate innovative safety management practices to address spatial and temporal needs of an intersection. For example, intersections with high commercial activities generating a high volume of pedestrian carrying overhead goods demand particular pedestrian phase with countdown signals. Further, to control pedestrians’ unruly behavior, adequate pavement marking, zebra crossing, designated bus stop facility, pedestrian signal head, and off-street parking facility should be provided along with the strict enforcement. Moreover, to enhance compliance with traffic signals, road safety campaigns, education, and awareness programs are must for better and safer road use.

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Pedestrian safety at traffic signals: A study carried out with the help of a traffic conflicts technique

Abstract

Accid. Anal. Prev.

Signalreglering och trafiksäkerhet, en före- efterstudie

Stockholms gatukontor, rapport nr. 14

Pedestrian accidents and exposure in Australia

Theory for strong validation, application to Swedish results

Traffic-conflicts technique for determining risk

The development of a method for traffic safety evaluation—the Swedish traffic conflicts technique