Modeling and Optimizing of Superelevation Rates: This Study is Based on the Regulations of Design Specification for Highway Alignment in China

摘要

The number of highway crashes, especially the number of rollover accidents, has been fast increasing with the development of highway constructions in China. Moreover, the current Design specification (JTGD20-2006) for Highway Alignment[1] in China only specifies maximum superelevation rates for different design speeds, and does not provide suggested value for a certain traffic condition. Therefore, this paper not only built a model of suprelevation for different design speeds and different curve radius based on the regulations of Design specification(Dtg D20-2006) for Highway Alignment, but also provided,an optimization method based on the model, which was established based on the comprehensive consideration of the influencing factors of distribution of vehicle, vehicle type, vehicle weight, vehicle dimension parameter, vehicle dynamic performance and actual speed. Through the calculation and analysis, the paper suggested superelevation rate should be adjusted to 9% from 8% when limiting minimum radius is 650 m, and the minimum radius without superelevation should be increased to 6000 m from 5500 m.