Estimating total manoeuvring time of drivers using Gamma distribution function of instantaneous speeds

Abstract

The Total Manoeuvring Time (TMT) of commuting drivers was analyzed by gamma density functions of vehic-le instantaneous speeds and transforming the functions to log normal distributions to determine the cumulative response times. The instantaneous speeds of 50 passenger vehicles were read from the speedometers at non-peak traffic periods on 4 segments of an urban arterial in Ilorin (Nigeria) in 2006. The ages of drivers, service period of vehicles, and pavement conditions were also obtained by interviewing the drivers. A model of cumul-ative response times of driver-vehicle-road interaction developed indicated that TMT was contributed by the interactions of driver perception-reaction time, steering time and vehicle response time in the proportion of 67 %, 22 % and 10 % respectively.