Necessity Analysis of Inside Shoulder Setting in Multi-lane Freeway with Traffic Simulation Method

"Technical Standard of Highway Engineering" regulated that eight-lane freeway should be provided 2.5-meter width inside shoulder. While several just completed widening to eight-lane freeways in China were not set inside hard shoulder, nor even wider than 0.75-meter curbs. The impacts of the behavior that a vehicle moves from the inside lane to the right shoulder on the operation speed were exploited under different volume and lane-change distances using traffic simulation method. The results indicated the significance and necessity of setting the inside shoulder of multi-lane freeway in terms of safety and efficiency once more.