Benefit–Cost Analysis of Florida High-Friction Surface Treatments

Abstract

High-friction surface treatments (HFSTs) are effective at reducing crashes on horizontal curves; however, HFST effectiveness on other roadway sections (e.g., tangents, intersections, intersection approaches) is not well documented. The crash reduction effectiveness of HFSTs in Florida was assessed, and the benefit–cost (BC) ratios for these section types were calculated. The researchers identified 23 HFST projects in Florida and attempted to collect data for each project, including bidding records, roadway geometry, and crash statistics. The cost data were based on the average comprehensive HFST unit cost and scaled by the size of the application. The benefit was estimated on the basis of 5-year extrapolations of average total and wet weather crash reductions. Savings were estimated on the basis of Florida Department of Transportation KABCO severity distribution of the crashes and an average cost per crash. On average, HFST applications on tight curves reduced the total crash rate by 32% and the wet weather crash rate by 75%. The average BC ratio on tight curve sections was between 18 and 26, depending on the benefit calculation method. Wide curve and tangents sections had few accidents initially, and HFST had negligible impact. From a crash perspective, wide curve and tangent HFST applications are not cost-effective. The effectiveness of HFST on intersection and approach applications is still inconclusive. Half the sections had good BC ratios and the other sections had negative benefit (increased crash rates). When considering the application of HFST, the engineer should consider whether there is an existing crash problem and whether it is skid related.