Abstract:
Roadway departure crash is the leading cause of highway crash related fatalities in Montana. Approximately, 64% of fatalities related to highway crash from 2010-2014 in Montana are related to single vehicle run-off the road crashes compared to the national average of 54%. The roadway departure crashes are more prevalent on rural than urban settings. Due to enormity of the problem a systemic analysis of roadway and low-cost treatment options across the entire roadway network is often a better option than providing expensive treatments on the pockets of networks that show excessive number of such crashes. This study shows an analytical framework to identify the roadway departure crashes on rural highways in Montana where low-cost safety countermeasures can be implemented. Montana uses roadway departure total and injury Safety Performance Functions (a.k.a. RD Total and RD Injury Model) in this screening. Network profiles are created on the predefined roadway segments by applying screening methods and segmenting criteria. The profile, composed of primary and secondary profiles, is then used in the systematic screening to identify the isolated locations as well as cluster of locations that show high propensity of roadway departure crash reduction by using the EB adjusted performance measures and level of service of safety (LOSS) as the criteria. A proactive screening methodology is also demonstrated using various types and degrees of geometric deficiencies and treatment strategies to assess the variability in cost and return on investment in different scenarios. The goal of this study is to identify and establish a consistent and standard method for Montana that can generate a safety work plan of roadway departure related treatments considering varying budgetary constraints.
