Recently, the concern over ISA has been growing in European countries. Introducing ISA into residential roads in Japan may significantly improve the traffic safety of bicycles and pedestrians. However, ISA also represses the convenience of drivers. The aim of this study is to develop a method for evaluating the burdens of drivers due to Mandatory ISA. Firstly, the factors affecting the speed selection of drivers on residential roads is analyzed based on a driving experiment. Secondly, based on the total cost minimization concept, a speed selection model which considers the trade-off between perceived accident cost and delay cost is developed. Then, the total cost which drivers perceive when driving at a certain speed under a certain road environment condition is estimated. The result shows that the perceived total cost will increase by 0.5% ~ 6.5% and 19% ~ 39% with the ISA limiting to 30 km/h and 20 km/h, respectively. (Author/publisher)
Abstract