ESTIMATION OF PASSENGER CAR UNIT FOR HETROGENEOUS TRAFFIC IN VISAKHAPATNAM

In developing countries including India, mixed traffic condition prevails on road and highways. Transportation grew to become the ‘economic’ backbone of any country. It assumes greater significance in urban context. There is a wide variation in the static and dynamic characteristics of dif ferent types of traffic. The method of accounting for traffic analysis in traffic stream is to convert all vehicles into a common unit known as passenger car unit (PCU). A number of factors have been identified affecting PCU values. In this study we are de aling with mainly three methods, which are Modified density method, Homogenization coefficient method and Time head way method. Modified density method assumes the homogeneous traffic and it is used by adjusting the method to handle heterogeneous traffic a nd is based on traffic entity and speed of the vehicle. Homogenization coefficient method depends on the size and speed of the vehicle whereas Time head way method depends on size, time head way and speed of the vehicles. Speed of the vehicle is calculated using spot speed studies by enoscope method. The PCU value for a vehicle is not a constant, it changes based on various parameters like speed, effective size of vehicle, road widths and from road to road and method applied for estimation of PCU