The effects of selected roadway and operational characteristics upon accidents on multilane highways were investigated. An attempt was made to determine if control of these characteristics, either during design or subsequent modification of the facility, would significantly affect the accident rate. Field data on both rural and urban sections were collected for 92 multilane highway sites in north carolina. Information on more than 6,000 accidents which occurred on these sites during a 21-month period in 1963 and 1964 was analysed. Attempts were made to correlate eight selected site characteristics, such as ADT volume, speed limit, and median width, with all injury accidents on the site. A multiple regression analysis was performed so the effects of all of the site characteristics could be examined simultaneously. Prediction equations, which could be used to measure the effects of any new set of variables on injury accidents for a new site, were developed. The effects of certain roadway characteristics on the frequency of median- opening accidents were also investigated. Although difficult to quantify, knowledge of the effects of the physical features of the roadway on the median opening accident rate is useful to the highway planner during decision-making and policy-formulation stages. (Author/publisher)
Samenvatting