This report documents the evaluation of the performance and safety effectiveness of passing relief lanes within the State of Michigan. The study began with the identification of passing relief lanes within Michigan. This was followed by collecting historical volume data, implementation dates and crash history for each of the 10 study sites as well as for the 100 reference sites and 231 passing lanes in the State. The analysis of the passing relief lanes within Michigan included a literature review, a best practices review and summary, an evaluation of the crash data via a naïve Empirical Bayes (EB) analysis and site visits to a select group of 10 passing relief lane study sites as determined by the study team. The site visits included speed data collection at a total of 50 locations; 5 locations for each passing relief lane study site. The analysis also found that the equivalent uniform annual benefit (EUAB) was less than 1.0; a cost analysis could not be conducted as no construction costs were available for the passing relief lanes. Based upon the results of the EB analysis, Crash Modification Factors (CMFs) were established to reflect the passing lanes in Michigan. (Author/publisher)
Samenvatting