Influence of green signal countdown timer on severe crash types at signalized intersections due to red light violations

ABSTRACT

Traffic conflicts at signalized intersections caused by red light violations (RLVs) present an enormous danger for severe crashes. This study proactively evaluates the efficacy of Green Signal Countdown Timer (GSCT) on RLVs and resulting right-angle and right turn related crashes (for left-hand driving) using Post Encroachment Time (PET). A before-after (B-A) with comparison group analysis is done considering five 4-legged signalized intersections from Delhi, India comprising of with and without SCT installations. RLV occurrences and maximum violation time during initial 10 s of red are more in the absence of GSCT. Considering various RLV-related characteristics, Powered Two Wheelers (P2W) are found to have the highest exposure in crash involvement for both timer conditions. Finally, B-A method shows 57.74% reduction in crossing conflicts due to the presence of GSCT at the sites. . Accordingly, SCT's installation can be recommended as a cost-effective engineering countermeasure to reduce severe crash types at signalized intersections.

KEYWORDS:

• Signalized intersection
• red light violation
• green signal countdown timer
• before-after study
• post encroachment time

Acknowledgments

The authors are grateful to the Accident Research Cell, Delhi Police: Traffic, Traffic Police (HQ), Todapur, Delhi for sharing accident data used in this research work.

Disclosure statement

The authors declare that they do not have any competing financial, professional, or personal interests from other parties.

Additional information

Funding

This work was supported by the Science and Engineering Research Board (SERB), Department of Science and Technology, Ministry of Science and Technology, Government of India under Grant SB/FTP/ETA-438/2012