Safety Evaluation of Green Light Optimal Speed Advisory (GLOSA) System in Real-World Signalized Intersection

The use of green light optimal speed advisory (GLOSA) systems is seen as a key application for achieving more environmentally friendly, time-efficient, and safer traffic flows at signalized intersections. In previous papers, the authors have proposed a GLOSA system that informs drivers of the most appropriate position for their vehicle instead of their optimal speed. This paper reports on a performance evaluation of our proposed GLOSA system after application to morning rush-hour traffic flow in a simulation of a real-world signalized intersection. A performance evaluation of this numerical simulation showed that our GLOSA system increased the time headway of vehicles and decreased their deceleration rates in the vicinity of the signalized intersection. In addition, the use of the system moderately increased fuel efficiency without affecting vehicle travel time. From these results, it can be concluded that our proposed GLOSA system has the potential to create safer traffic flows in real-world signalized intersections without degrading traffic efficiency.

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A New Approach to Green Light Optimal Speed Advisory (GLOSA) Systems and Its Limitations in Traffic Flows

Human Systems Engineering and Design - Advances in Intelligent Systems and Computing ◽

10.1007/978-3-030-02053-8_118 ◽

2018 ◽

pp. 776-782 ◽

Cited By ~ 2

Author(s):

Hironori Suzuki ◽

Yoshitaka Marumo

Keyword(s):

Green Light ◽

Traffic Flows ◽

New Approach ◽

Optimal Speed

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PEDESTRIAN SAFETY EVALUATION OF SIGNALIZED INTERSECTIONS USING SURROGATE SAFETY MEASURES

Transport ◽

10.3846/transport.2020.12157 ◽

2020 ◽

Vol 35 (1) ◽

pp. 48-56

Author(s):

Sankaran Marisamynathan ◽

Perumal Vedagiri

Keyword(s):

Safety Evaluation ◽

Pedestrian Safety ◽

Signalized Intersections ◽

Signalized Intersection ◽

Mixed Traffic ◽

Model Framework ◽

Safety Measures ◽

Severity Level ◽

Traffic Conditions ◽

Surrogate Safety Measures

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.

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Safety Evaluation of Alternative Signal Head Design

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1635-19 ◽

1998 ◽

Vol 1635 (1) ◽

pp. 140-146 ◽

Cited By ~ 5

Author(s):

Tarek Sayed ◽

Walid Abdelwahab ◽

John Nepomuceno

Keyword(s):

Empirical Bayes ◽

Traffic Accidents ◽

Red Light ◽

Green Light ◽

Safety Evaluation ◽

Signalized Intersections ◽

Effective Measure ◽

Amber Light ◽

Standard Signal ◽

Before And After

A before and after safety evaluation of the installation of a larger signal head design was conducted. The design consists of a 300-mm red light, a 300-mm amber light, and a 300-mm green light, all with 150-W lamps and a yellow backboard with an additional 50-mm reflective border. The signal head design was field tested in 10 urban intersections in British Columbia. The intersections were originally equipped with the standard signal head design consisting of a 300-mm 150-W red light; a 200-mm 69-W amber light, and a 200-mm 69-W green light, with a yellow backboard. An Empirical Bayes before and after safety analysis indicated that the improved signal head design had a significant effect in reducing the overall frequency and severity of accidents at the treatment sites. Accidents were reduced by approximately 24 percent; injury and fatal accidents were reduced by approximately 16 percent. Classical simple before and after techniques were found to overestimate these benefits by approximately one third. It is concluded that increasing traffic signal visibility through the improvement of signal head design is an effective measure of reducing both the frequency and severity of traffic accidents at signalized intersections.

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