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This study reports the safety benefits associated with the installation of Variable Speed Limit System (VSLS) on provincial highways in British Columbia (BC), Canada. A VSLS is an intelligent transportation system (ITS) that aims at increasing the safety level on highways by varying the speed limit according to downstream operational condition and/or weather conditions. The analysis made use of police-attended serious crashes (i.e. fatal + injury) that took place during winter seasons. 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 showed 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. The EB analysis showed an overall 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 Net Present Value (NPV) of C$34.41 million. The results of this study may motivate stakeholders who are interested in pursuing similar systems for mitigating weather-related safety challenges. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to evaluate the safety effectiveness of cable barrier systems installation on rural highway sections in British Columbia, Canada.Methods: Data on police-attended serious collisions (injury + fatality) on a number of rural highway sections in British Columbia, Canada, were used in the analysis. An empirical Bayes (EB) approach was employed to ensure that the evaluation results were reliable and to account for the regression to the mean artifact. Safety performance functions (SPFs) were developed using data collected at similar sites. For both median cable barrier (MCB) and roadside cable barrier (RCB) sections, the evaluation was undertaken using all serious collisions, truck serious collisions, and off-road serious collisions.Results: For MCB sections, the evaluation results showed statistically significant reductions of 21.7, 53.8, and 34.8% in all serious collisions, truck serious collisions, and off-road left (ORL) combined with head-on (HO) serious collisions. For RCB sections, statistically significant reductions of 74.7, 100, and 100% were found in all serious collisions, truck serious collisions, and off-road right (ORR) serious collisions, respectively. The impact of the after period on the evaluation results was explored. It was found that the changes in safety become more stable using an after period of 2-5 years.Conclusions: Cable barriers were successful in reducing the frequency of serious collisions on provincial highways in British Columbia. [ABSTRACT FROM AUTHOR]