Study on the influence of bus front-end intrusion-free distance to the bus moving characteristics

Buses are usually loaded with many passengers and cannot start and turn around flexibly while cars are light and maneuverable. Sometimes, cars may cut in front of a bus as long as the gap is available, and buses have to reduce their speed, which affects the traveling speed and smoothness of buses. In order to improve the bus riding quality, this paper proposes a model of setting front-end intrusion-free distance, in which social vehicles are not allowed to cut in. If buses accelerate, the distance from front vehicles can be smaller than the intrusion-free distance. With open boundary conditions, social vehicles and bus departure mechanism were reenacted, and a two-lane mixed traffic cellular automaton model based on different lane changing conditions and whistle effect was established respectively. Simulation results demonstrated that the model reproduced the operation rules of mixed flow on driveways, with good performance in describing lane changing rules. According to numerical simulation, the suggested vehicle changing lane regulation not only accelerated buses, but also increased the average speed of overall passengers, with improved smoothness of road vehicles, and reduced lane changing times and vehicle acceleration and deceleration frequency. It was demonstrated that the front-end intrusion-free distance for public buses can optimize bus operation efficiency.