PASSENGER CAR UNIT VALUES FOR URBAN ROADS

The passenger car unit (pcu) value of each class of vehicles has been found to be of prime importance in the study of mixed traffic flow, particularly in studies concerning traffic flow parameters, capacity, signal design and parking lots. Though the pcu values to be used for the different classes of vehicles on rural road stretches have been proposed by the Indian Roads Congress, the values for urban road stretches, intersections and kerb parking have not yet been standardised for use in India. A study was conducted on typical urban roads so as to cover different aspects of road geometrics, traffic and environmental conditions. A model has been developed for arriving at pcu values. Three sets of pcu values have been worked out for (i) urban road stretches (mid-block sections), (II) signalized intersections, and (III) kerb parking. These values may be tentatively adopted on urban roads in India until more rational and variable design vehicle units dependent on roadway and traffic factors are developed. (TRRL)