DETERMINATION OF CAPACITY AT TRAFFIC WARDEN CONTROLLED INTERSECTION USING FIXED-TIME SIGNALISED INTERSECTION CAPACITY MODEL

Models have been developed in literature for the determination of capacity at fixed-time signalised intersection. In Nigeria and some developing economy the human controlled intersection is prevalent where the recurring green time and cycle length are not fixed but vary. A 15-minute study was carried out for 7 days at AM, afternoon and PM peak periods during which the signalization pattern and time allocation of right-of-way as carried out by the human traffic controllers at the study location was observed. The ratio of the total green time (gt) allotted to an approach during the 15-minute study period to the study period (900 seconds) which is taken as the cycle length (Cl), gave the green time/cycle length ratio needed as input to compute capacity in fixed-time signalized intersection capacity model. The approach used in the study is recommended for computing capacity at a traffic warden controlled intersection as it overcomes the difficulty encountered in using the manual method of delay survey where the stopped and non-stopping vehicles on an approach is counted particularly when the queue length on an approach is long. [PUBLICATION ABSTRACT]