The Highway Safety Manual (HSM) lists four different methods for determining the change in crash frequency in order of reliability. Currently, the Utah Department of Transportation (UDOT) uses the fourth reliable method. The goal of this research was to develop a tool that the most reliable method mentioned in the HSM could be used to perform life-cycle benefit-cost analyses. A spreadsheet program was built that performs the HSM's Part C Predictive Method for 11 different roadway segment types mentioned in HSM using Excel macros and Visual Basic for Applications (VBA) programming. Intersections were not included in this spreadsheet program as they were not included in the Utah Crash Prediction Model (UCPM) or the Utah Crash Severity Model (UCSM) at the time of this research. The methodology for analysis was set up to become part of the use of the models in selecting countermeasures. The concept and spreadsheet layout are discussed using the rural two-lane two-way (TLTW) highway spreadsheet as an example. Three examples are presented in this thesis, which are a case of rural TLTW highway, a case of five-lane urban arterial with a two-way left-turn lane (TWLTL), and a case of a freeway segment, each with two selected countermeasures to compare their benefit-cost ratios (BCRs). One important aspect associated with life-cycle benefit-cost analysis of safety related improvements is the cost of countermeasures. The spreadsheets developed in this research can predict the benefits associated with a countermeasure following the methods found in the HSM; however, it does not include a module to estimate costs associated with a countermeasure to be selected because costs of countermeasures are dependent on the way such improvements are included in construction contracts. The engineer should seek guidance from the cost estimate expert within the agency or outside consultants when determining the project costs.
College and Department
Ira A. Fulton College of Engineering and Technology; Civil and Environmental Engineering
BYU ScholarsArchive Citation
Frustaci, Jordan Browne, "Life-Cycle Benefit-Cost Analysis of Safety Related Improvements on Roadways" (2016). All Theses and Dissertations. 6109.
life-cycle, benefit-cost, safety, analysis