Calculation Methods of Minimal Headway for High-Speed Railways

This paper analyzes the interaction process of the running trains associated with the minimal headway for high-speed railway in a more reasonable and sophisticated way after systemically investigating previous researches. A set of new formulas are proposed to improve the calculation accuracy of minimal headway. In the case study section, the proposed methods are tested to calculate the minimal headway of the running trains of different speeds range from 250 km/h to 350 km/h with the calculation step of 10 km/h. The case study results show that with the increase of the maximal allowed speed, the headway between two trains running in one section, the headway between two arrival trains and the minimal headway of the high-speed railway increase, while the headway between two departing trains is a constant. The main conclusions can be drew from the case study results: (1) Headway between two arrival trains is always the bottle neck to narrow down minimal headway of high-speed railway no matter how the maximal allowed speed of the train changes from 250 km/h to 350 km/h. (2) The minimal headway of high-speed railway is always greater than 180 s with the maximal allowed speed of the train ranges from 250 km/h to 350 km/h, which means that some improvement measures should be taken to accomplish the goal of reducing minimal headway to 3 min. (3) The improvement of braking performance of the train can reduce the minimal headway of high-speed railway.