TRAVEL TIME VARIABILITY ANALYSIS: THE CASE OF KUMASI, GHANA

: Travel time variability describes the adjustable and probable changes in travel times that occur during a typical trip on a monitored road segment. Fluctuations in the travel time have direct impact on the route capacity which, in turn, negatively impacts the effectiveness of operational measures of the subject route’s capacity. In this study, travel time analysis was carried out for three different frequently used road segments using three different travel modes: private and commercial (mass transit (“trotro”) and shared taxis) for 13 days by measuring travel times from start to the end of each study section. Three different times of day were employed for the analysis that is the morning peak (7:00am to 10:00am), afternoon peak (1:00pm to 3:00pm) and the evening peak periods (4:00pm to 7:00pm). The results obtained suggest that there are huge variations in the travel time variability for both the morning, afternoon and evening peak periods for the three travel modes studied on the selected routes. The paper concludes that the wide differences in travel time variability, which could be attributed to the prevalence of side friction agents and multiple stops, make trip planning and its related prediction efforts extremely challenging and recommends a scale-up of study to establish the conclusions made from this study.