Analyzing freeway travel times within a case study: Reliability of route traversal times

With the motivation of figuring out the reliability of link and route traversal times, we decompose our research into two stages those summarize modeling of travel times as a link performance and the analysis on the distribution and reliability of reconstructed travel times. In a separate paper, we seek the performance of two models by adopting traffic flow theory based reconstruction approaches. An overall evaluation on freeway travel time reconstruction performance of both a macroscopic and a microscopic model are presented considering real data obtained within a case study conducted on a stretch of Istanbul freeway network. While the initial paper presents the simulation results on both day and flow direction basis, we further consider the results in the explicit analyses on distributions and reliabilities of model reconstructions in the present paper. In order to investigate the distributions of route traversal times by considering explicitly the day-to-day variations, we apply the fitness test of normal distribution to the overall reconstructions by 5 weekday data and then proceed with the standardization of reconstructions and derivation of day-to-day distributions. Statistics obtained as order moments of travel time random variable are considered in the indication of reliability.