Analysis of accidents in construction and maintenance work zones

Abstract

This report includes documentation of the two following phases of the study: 1) analysis of statewide accidents for the period 1983 through 1986 in which road under was listed as a contributing factor; and 2) analysis of accident data and traffic control devices used at 20 case study locations. At the case study locations, accident data were analyzed for a three year period before construction and compared to the period during construction. Results from the statewide analysis indicate that even though the level of construction and maintenance activity is higher and traffic volumes have increased, there have not been significant increases in work zone accidents. The number of accidents reported as occurring in work zones has remained at approximately 500 per year for the period 1983 through 1986. In general, characteristics of work zone accidents are that they are more severe than other accidents; there are high percentages of rear end and sideswipe accidents; following too close was the most frequently listed contributing factor, and there was a high percentage of accidents involving trucks. Results from the analysis of case study locations revealed that at most sites (14 of 19) the accident rates during construction exceeded those before construction. It also was found that 10 of the 14 sites had rates during construction that exceeded statewide averages and 6 of the 14 exceeded statewide critical rates. Only four case study sites had rates during construction that exceeded the statewide critical rate with the before period less than the statewide critical rate. Similar characteristics (types of accidents and contributing factors) were found to exist at the case study locations when compared to statewide work zone accidents. Traffic control at case study sites was generally found to be in conformance with specified standards. Two lane, two way operations were used successfully at five case study sites (A).