Empirical study on traffic system management applied to the metropolitan expressway during the Tokyo 2020 Olympic games

This paper presents an empirical analysis of Traffic System Management (TSM) applied to a Metropolitan Expressway (MEX) during the Tokyo 2020 Olympics. In this study, we examined how TSM strategies, including onramp closure and junction control, integrate event-related traffic with general traffic in an expressway network. By utilizing comprehensive traffic data, traffic demands were estimated from the slope of the “imaginary” cumulative arrival curve, and total delays were calculated based on observed speed and volume. The effects of TSM were then evaluated by comparing the results from the actual implementation scenario with those in a constructed counterfactual scenario without TSM. The findings revealed that TSM reduced traffic demands by 3.23 % on weekdays and 0.77 % on Saturdays, Sundays, and Holidays (SSHs), whereas it reduced total delays by 26.90 % on weekdays and 8.69 % on SSHs on average. We also found that the reduction in total delays by TSM largely varied day by day, associated with a large variation in the total durations for which TSM was implemented. Moreover, this study systematically evaluated TSM rationalities based on breakdown probabilities and proposed a schedule for improvement. This suggests that by intensively implementing regular TSMs during peak hours with an advanced starting time, congestion at stationary bottlenecks can be avoided, thus shortening the total duration of TSM implementations. The estimation results further suggest that the proposed TSM can reduce travel time while accommodating more traffic volume, thereby enhancing the efficiency of transport systems.