Causeway Intersection And Adjacent Ground Type Expressway Entrance Minimal Space Research

The spacing of the ground type expressway and expressway not only affects the location of the flat, but also the traffic safety. The big cities of developed countries have built quite perfect expressway system, but our country is in start level, system researches of the expressway are just to begin, the theory and practice should be accumulated. This paper studies the theory and practice of the expressway at home and abroad, and analyzes the entrance space between the flats, to expressway design, which can provide a certain technical reference to the designing, construction and management of expressways in our country.The paper makes definition to the ground type expressway and expressway entrance spacing. Component in a minimum distance are analyzed, and influence the size of the spacing of many factors, considering the driver the most unfavorable situation, on the basis of using the driveway transform theory and gap acceptance theory, in meet the demand of vehicles on the road, on the basis of established the ground type expressway and expressway entrance so minimum distance calculation model, and recommended value of the minimum distance is given.With reference to the Highway Capacity Manual and Urban Road Engineering Design Specification in our country about the division of service level standard, use traffic density as the evaluation index, the maximum service traffic volume under the target service level as the calibration value of the traffic simulation traffic, using VISSIM to the ground type expressway and expressway entrance so minimum distance recommended value for simulation. Determine the simulation operation process, the use of experiment output to the validation of the ground type expressway and expressway entrance minimum distance so the rationality of the recommended value, finally it is concluded that both can meet the demand of vehicle with the minimum distance satisfies the requirement of the target service level recommended value. Existing in the current city small spacing section, from the perspective of traffic safety, driving comfort, the corresponding countermeasures put forward a series of design and traffic control measures.The research results can provide the technical support for expressway and along the road system connecting control.