The Indonesian HCM (Highway Capacity Manual) project started in 1990, and a draft manual was published in January 1993 based on surveys at 33 unsignalised intersections and 27 weaving areas in 13 cities using high mounted video camcorders synchronised with a 32 channel data logger. The collected data included traffic flow and composition, existence of queues, travel time, and driver behaviour in conflict points. Pcu values obtained were: heavy vehicles 1.3; motorcycles 0.5 and unmotorised 1.0. Less than 40% of the minor road vehicles waited for gaps in the major road flow; those who did had very short critical gaps (2.1 sec). The capacity for unsignalised intersections was therefore typically 50% higher than in developed countries. For single weaving sections, an empirical model was developed, also giving high capacities. For roundabouts, the lack of an `inside priority rule' in Indonesia made the risk for congestion very high even at moderate flows. (A)
Samenvatting