The Analysis and Assessment of Black Spots (From the Viewpoint of Accident Location Recognition, Costs of Damages and Remedial Works)

Roads, humans and vehicles are the three major factors in road traffic accidents occurrence. Road geometry, as one of the fundamentals of the road environment, has a key role in reducing human errors. The treatment or elimination of black spots has a great influence in safety promotion, reducing the number of road traffic accidents, and, subsequently, diminishing damages. In this paper, the process of analysis and assessment includes: 1) accident location identification, 2) costs of damages, and3) remedial works.Based on statistical analyses and assessments, engineering economics techniques and hierarchical methods were carried out. As a case study, Shiraz–Isfahan corridor, which is an important arterial road in Iran's road network, was chosen. The results are as follows:1- Calculation of the accident costs shows the fact that the average costs of a fatal accident is approximately 5 times the costs of an injury accident and 9 times the average of damage accidents.2- The statistics and data confirm that %20 of accidents occur in the accident-prone places (black spots). This represents the importance of treatment and investment for safeguarding critical and accident-prone points in the roads.3- The average of Benefit/Cost ratio (B/C) in executing safety improvement projects in Shiraz–Isfahan corridor is 20.3, which shows the strong economic feasibility of such projects.4- The ranking for implementation of safety projects in a multi-criteria decision making model is based on the number of accidents.5- According to the accomplished analyses, the points and locations with more traffic volume have more priority for the implementation of safety projects.