An ANP-based Model for Location of Fixed Speed Cameras

Speeding is a major cause of traffic accidents and is estimated to be the cause of about 40% of fatalities in road accidents. Speed is a major accident risk factor and affects both rate and severity of traffic accidents. This importance has led to universal use of intelligent control systems for maintaining road safety by enforcing speed regulations. In this study, a modeling is carried out by the use of Analytic Network Process (ANP) based on the expert opinion to determine the importance of several criteria for location of speed cameras. Modeling was carried out using the opinions expressed in a meeting with an expert group consisting of two credible experts on traffic and transportation, one traffic officer, and one expert on traffic accident. Criteria, alternatives, and the relation between factors were discussed in meeting and the results were recorded only after reaching a consensus. The basic model was developed, and then quantified by introducing the numbers and relations suggested by experts. Camera location criteria considered in this study are police presence, effect of traffic control equipment, lighting conditions, history of accidents (in the last three years), and land use adjacent to the studied road segment. Accident statistics was used as the measure of road segment’s recent safety. For this purpose, history of accidents in each segment in the last three years was collected. The accidents resulting no injury or fatality were given a weight of 1, accidents leading to injury were given a weight of 3, and fatal accidents were given a weight of 9.  Hamedan’s third ring road is then used as a case study to evaluate the model. The results show that Ahmadi Roshan Blvd. is the top priority for installation of speed cameras.