A dynamic pedestrian to infrastructure scheme around metro areas. A traffic microsimulation study in Thessaloniki, Greece

The promotion of sustainable mobility in urban areas is directly correlated with efforts to encourage the shift to alternative modes of transport, such as public transport (PT) and walking. A prerequisite to encouraging users to use PT is the improvement of pedestrian infrastructure around stops/stations, in order to enhance accessibility and comfort. The present paper aims at studying pedestrian travel patterns and optimizing transport infrastructure around one of the most central stations of the upcoming metro system in the city of Thessaloniki, Greece, where pedestrian flows are expected to increase significantly upon operation. In the framework of the paper various scenarios are studied using the Vissim/Viswalk microsimulation software. The first scenario (Scenario 0) replicates the existing travel conditions, i.e. without the metro in operation. Results indicate satisfactory levels of service for the surrounding sidewalks and pedestrian crossings. After the development and calibration of the baseline model two (2) alternative scenarios are formulated, concerning the metro in operation. In Scenario 1, the performance of the network without any optimization procedures is studied. Results indicate lower levels of service overall, which is expected due to the increased demand (4,000 additional pedestrians at peak hour). From the outcomes of Scenario 1, improvement actions are deemed necessary since significant delays in escalators and pedestrian crossings with local arterial roads are anticipated. In Scenario 2, the optimization of a nearby pedestrian crossing is examined with the exploitation of cooperative infrastructure (vehicle-to-infrastructure, pedestrian-to-infrastructure). Specifically, the traffic light cycle and the corresponding green time for pedestrians and vehicles alike are dynamically adjusted according to traffic conditions, in order to limit pedestrian waiting time and thus improve accessibility, comfort and road safety. Results of this paper could work as basis for metro system operators and transport planners, in their effort to improve accessibility around busy metro stations.