Study Details
Study Title: Evaluating the Effectiveness of the Safety Improvement Program in Saskatchewan Using an Observational Before-After Study with the Full-Bayes Approach
Authors: Sacchi and Tayebikhorami
Publication Date:JAN, 2021
Abstract: A key step in highway safety management is to determine whether the frequency and/or severity of collisions have been reduced after implementing a specific improvement program. This research focused on evaluating the safety performance of 50 sites that have been improved under the Saskatchewan Ministry of Highways and Infrastructure’s (MHI) Safety Improvement Program (SIP). SIP projects were designed to reduce the frequency and severity of collisions on provincial highways in rural areas through the implementation of different safety countermeasures. The methodology adopted was an observational before-after study with the full Bayes approach. The results showed that SIP projects reduced total collisions by 14.8% and severe (fatal-plus-injury) collisions by 25.4%. The reduction of property-damage-only collisions was not found to be statistically significant. Crash modification factors (CMFs) for the two most frequent SIP treatments, i.e., right-turn lanes and delineation lighting at intersections, were estimated and compared to the results of the literature.
Study Citation: Sacchi, E. and S. Tayebikhorami. "Evaluating the Effectiveness of the Safety Improvement Program in Saskatchewan Using an Observational Before-After Study with the Full-Bayes Approach". Canadian Journal of Civil Engineering, (2021).
Study Report: Download the Study Report Document
CMFs Associated With This Study
Category: Highway lighting
Countermeasure: Install intersection lighting
CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
---|---|---|---|---|---|---|
0.792 | 20.8 | All | All | All | Rural |
Category:Intersection geometry
Countermeasure: Install right-turn lane
CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
---|---|---|---|---|---|---|
0.834 | 16.6 | All | All | All | Rural |