The Analysis of the Motorway Vehicle Gap and Designing the Device of Protectiving Vehicle Collision Zheng An′wen Assoc. Prof. ,College of Urban Construction,Wuhan University of Science and Technology , Wuhan 430070,China.According to the vehicle collision features in the motorway, on the basis of vehicle gap's formulae,the relation of changing vehicle gap and protective vehicle collision is analyzed. The design of device protecting vehicle collision is discussed.motorway;\ vehicle gap;\ collision accident;\ protective device