One unique feature of large South Asian cities is the composition of its urban street traffic. Because many different traffic entities of varying sizes continuously interact on the street space, the traffic mixture is heterogeneous. Heterogeneous traffic increases street capacity. Homogeneous traffic prevails in North America, Europe, and Australian cities. Two broad categories compose heterogeneous traffic, i.e., motorised vehicles and nonmotorised entities. After collecting geometric, composition, speed and conflict data at fourteen sites at midblock, an analysis examines the degree of heterogeneity aspect of traffic at a microscopic level. The best model showed that the high fatality midblock sites correlate to unidirectional street widths at +0.89. The degree of heterogeneity and motorised traffic flow had the strongest relationship with street width at a +0.99 correlation coefficient. Keeping motorised vehicular flow constant showed that fatalities are reduced when the traffic heterogeneity index equalled one, a 50% motorised and 50% nonmotorised composition. (A)
Samenvatting