scholarly journals Exploring pedestrian surrogate safety measures by road geometry at midblock crosswalks: A perspective under mixed traffic conditions

Author(s):  
Avinash Chaudhari ◽  
Ninad Gore ◽  
Shriniwas Arkatkar ◽  
Gaurang Joshi ◽  
Srinivas Pulugurtha
Transport ◽  
2020 ◽  
Vol 35 (1) ◽  
pp. 48-56
Author(s):  
Sankaran Marisamynathan ◽  
Perumal Vedagiri

The large proportions of pedestrian fatalities led researchers to make the improvements of pedestrian safety at intersections. Thus, this paper proposes a methodology to evaluate crosswalk safety at signalized intersections using Surrogate Safety Measures (SSM) under mixed traffic conditions. The required pedestrian, traffic, and geometric data were extracted based on the videographic survey conducted at signalized intersections in Mumbai (India). Post Encroachment Time (PET) for each pedestrian were segregated into three categories for estimating pedestrian–vehicle interactions and Cumulative Frequency Distribution (CDF) was plotted to calculate the threshold values for each interaction severity level. The Cumulative Logistic Regression (CLR) model was developed to predict the pedestrian mean PET values in the cross-walk at signalized intersections. The proposed model was validated with a new signalized intersection and the results were shown that the proposed PET ranges and model appropriate for Indian mixed traffic conditions. To assess the suitability of model framework, model transferability was carried out with data collected at signalized intersection in Kolkata (India). Finally, this study can be helpful to rank the severity level of pedestrian safety in the crosswalk and improve the existing facilities at signalized intersections.


Author(s):  
P. Vedagiri ◽  
Deepak V. Killi

In the developing world, with increases in population, the number of vehicles is increasing tremendously. Traffic safety on roads has become a major concern even with advancements in technology and infrastructure. Traffic safety assessments and accident prediction based on accident data is a reactive approach. There are known drawbacks related to the reliability of accident data, especially in developing countries with large populations, such as India. It is, however, unethical to wait for accidents to occur before drawing statistically accurate conclusions regarding safety impacts. To overcome this impediment, one needs to develop accurate models that rely on surrogate safety measures (SSMs) for effective safety evaluations. The main advantage associated with the use of these models is that they can model crashes more frequently than in the real world and thereby imply an efficient and more statistically reliable proximal measure of traffic safety. The objective of this study is to examine the impact of management measures on traffic safety at a three-arm uncontrolled intersection with the use of microsimulation modeling under mixed traffic conditions. This examination was done by developing a unique methodology of measuring one SSM, postencroachment time (PET). This paper describes improvement in the accuracy of crash predictions by proposing a methodology to calculate PET.


2017 ◽  
Vol 2659 (1) ◽  
pp. 137-147 ◽  
Author(s):  
Peibo Zhao ◽  
Chris Lee

This study analyzed rear-end collision risk in a mixed traffic flow of cars and heavy vehicles on a freeway using two surrogate safety measures: time to collision (TTC) and postencroachment time (PET). The study estimated surrogate safety measures for types of lead and following vehicles (car or heavy vehicle) by using the individual vehicle trajectory data. The vehicle trajectory data were collected from a segment of the US-101 freeway in Los Angeles, California. It was found that the distributions of TTC and PET were significantly different between types of lead and following vehicles. Also, the mean values of TTC and PET were higher for heavy vehicles following cars than for cars following cars and for cars following heavy vehicles. The study also validated TTC by using the simulated traffic data for a few minutes before the time of crashes that occurred on a section of the Gardiner Expressway in Toronto, Ontario, Canada. It was found that TTC reflects higher collision risk in the time intervals closer to the crash time and it reflects higher collision risk for the crash case than for the noncrash case. The findings suggest that the difference in rear-end collision risk between types of vehicle pairs should be considered in safety assessment of mixed traffic flow of cars and heavy vehicles.


2021 ◽  
Vol 147 (4) ◽  
pp. 04021006
Author(s):  
Bhargav Naidu Matcha ◽  
Sivakumar Sivanesan ◽  
K. C. Ng

2011 ◽  
Vol 16 ◽  
pp. 676-685 ◽  
Author(s):  
Joewono Prasetijo ◽  
Mehdi Hossein Pour ◽  
Seyed Mohammad Reza Ghadiri

2017 ◽  
Vol 143 (8) ◽  
pp. 04017041 ◽  
Author(s):  
Arpita Saha ◽  
Satish Chandra ◽  
Indrajit Ghosh

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