EFFICIENCY ANALYSIS OF TRAFFIC SAFETY COUNTERMEASURES

For the macroscopic investigation of traffic safety, the ministry of construction (moc) has collected a lot of accident data throughout the designated sections of national highways which are administrated by the minister of construction; the total length of the sections is about 20000 km. The public works research institute (pwri), which is an auxillary organ of the ministry, has analysed these data. This report is a summary of one of the studies aimed to identify the efficiency of the traffic safety countermeasures. The accident data in the year before and after the installation of six kinds of safety facilities such as pedestrian bridge, central barrier, guard rail, bus bay, road lighting and delineator were collected and processed in statistical and probability analysis methods. It was found that the average reduction rate of traffic accidents by the installation of them is 52%, which could be said to be "effective". Comparing with the average accident rate of national highways, which is about 80 accidents per 100 million vehicle kilometer, it can be said that installations of these facilities improved the hazardous highway segments into ordinary safe segments. (TRRL)