Safety Evaluation of Variable Speed Limit System in British Columbia
Adverse weather conditions create a difficult environment for drivers to navigate safely. Reducing weather-related collisions is a priority in British Columbia (BC), Canada. This study reports the safety impacts associated with the installation of Variable Speed Limit System (VSLS) on provincial rural highways in BC. A VSLS is an advanced intelligent transportation system (ITS) scheme that can be employed to increase the safety level of highway facilities by varying the speed limit according to downstream operational condition and/or current weather conditions. The analysis made use of police-attended serious crashes (i.e. fatal + injury) that took place during winter seasons (October to March). Three winter seasons were available as a before implementation period, and three winter seasons were available as an after-implementation period. The results of a simple-before-and-after were promising where overall reductions of 35.8% and 36.8% in winter serious collision (WSC) frequency and rate, respectively, were found for the evaluation corridors. An Empirical Bayes (EB) before-and-after safety evaluation was also carried out to ensure that the results are reliable. Safety Performance Functions (SPFs) were developed using data collected at similar sites. The EB analysis showed an overall statistically significant reduction of 34.4% in WSC. An economic assessment of the system was undertaken and the results showed that the benefits of implementing a VSLS exceeded the system cost with an overall benefit cost (B/C) ratio of 4.3 and a NPV of C$34.41 million. The results of this study may motivate transportation agencies and stakeholders who are interested in pursuing similar systems for mitigating weather-related safety challenges.
- Record URL:
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Supplemental Notes:
- This paper was sponsored by TRB committee ACS20 Standing Committee on Safety Performance Analysis.
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Corporate Authors:
Transportation Research Board
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Authors:
- El Esawey, Mohamed
- Sengupta, Joy
- Babineau, John E
- Takyi, Emmanuel
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Conference:
- Transportation Research Board 100th Annual Meeting
- Location: Washington DC, United States
- Date: 2021-1-5 to 2021-1-29
- Date: 2021
Language
- English
Media Info
- Media Type: Digital/other
- Features: Figures; References; Tables;
- Pagination: 18p
Subject/Index Terms
- TRT Terms: Bayes' theorem; Before and after studies; Crash data; Economic impacts; Highway safety; Rural highways; Traffic crashes; Variable speed limits; Weather conditions; Winter
- Geographic Terms: British Columbia
- Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; Safety and Human Factors;
Filing Info
- Accession Number: 01764259
- Record Type: Publication
- Report/Paper Numbers: TRBAM-21-00013
- Files: TRIS, TRB, ATRI
- Created Date: Feb 4 2021 11:00AM