SCHEDULING IMPROVEMENTS FOR HIGH-ACCIDENT HIGHWAY LOCATIONS BY MEANS OF INVESTMENT RETURN ANALYSIS

AN ANALYSIS IS PRESENTED OF 6 OUT OF 1,560 HIGH-HAZARD HIGHWAY LOCATIONS FOR POSSIBLE TREATMENT UNDER THE SPOT IMPROVEMENT SAFETY PROGRAM OF THE NORTH CAROLINA STATE HIGHWAY COMMISSION. THE OBJECTIVE AND SCOPE OF THE ANALYSIS IS DESCRIBED. REVIEW OF LITERATURE SUMMARIZES PREVIOUS STUDIES OF HIGHWAY SAFETY IMPROVEMENT. SELECTION OF STUDY SITES LISTS THE CRITERIA EMPLOYED FOR SELECTING THE HIGH-HAZARD SPOTS. TO BE INCLUDED, A LOCATION HAD TO HAVE AN ACCIDENT RATE OF 3.8 ACCIDENTS PER MILLION VEHICLE MILES OR GREATER. THE METHODS USED IN THE COLLECTION OF ACCIDENT AND IMPROVEMENT COST DATA ARE DISCUSSED. SUGGESTED ANALYTICAL PROCEDURE PROPOSE SOME STEPS NEEDED TO EVALUATE A SAFETY IMPROVEMENT IN TERMS OF FINANCIAL "INPUT" AND "PAY-OUT." ANALYSIS OF TEST SITES OFFERS THE DATA FROM INVESTMENT RETURN ANALYSIS MADE ON EACH OF THE 6 SELECTED TEST SITES, AS WELL AS A BENEFIT/COST ANALYSIS.THE RESULTS OF THE STUDY ARE SUMMARIZED: (1) IT IS OBVIOUS FROM THE DATA THAT THE 2 PROCEDURES USED, INVESTMENT RETURN ANALYSIS AND BENEFIT/COST ANALYSIS, WILL PRODUCE SIMILAR RESULTS FOR ANY GIVEN IMPROVEMENT LOCATION. EITHER METHOD WOULD HAVE ASSIGNED THE SAME PRIORITY TO EACH OF THE SELECTED SITES. (2) THE INVESTMENT RETURN ANALYSIS, HOWEVER, HAS ADVANTAGES, ALTHOUGH, EVEN WITH THIS METHOD OF ASSIGNING PRIORITIES, CONSIDERABLE PERSONAL JUDGMENT MUST BE USED IN BOTH THE DETERMINATION OF THE PAYBACK PERIOD AND IN ASSIGNING A PRIORITY TO THE PROJECT ONCE ITS RELATIVE PLACE AMONG THE OTHER PROJECTS HAS BEEN DETERMINED. /AUTHOR/