The report describes a computer program (picady 1) which predicts capacities, queues and delay at 3-way major/minor junctions. The program is intended to be used by traffic engineers for design and assessment purposes. The basic input data consist for each arm of a time 'profile' of demand flows, turning proportions, percentages of heavy vehicles and certain geometric characteristics. Picady calculates, for each of a succession of short, consecutive time intervals (during a peak period, for example), the capacity, average queue length, and delay expected in those traffic streams which have to give way to other vehicles - the right- and left-turning minor road streams and the right-turning major road stream. The flows, delays and queue lengths occurring in each time interval, and the overall flows and delays, are printed out by the program. The latest formulae for the capacity of traffic streams at major/minor junctions, and time-dependent queueing equations, are used for this purpose. Details of program operation and input requirements are given, together with worked examples. (Author/publisher)
Abstract