The Importance of Assessing the Level of Service in Confined Infrastructures: Some Considerations of the Old Ottoman Pedestrian Bridge of Mostar

Walking is classified as the oldest transport mode with the least impact on the environment. It is frequently one of the intermediate transport modes. Generally, while designing exclusive walking transit areas or structures with high human traffic volumes and considering different scenarios, it is advantageous to be able to foresee the congestion conditions and the relative problems. The study of pedestrian trajectories, which are strictly related to the characteristics of the walkers, is necessary and preliminary for the purposes of an in-depth analysis linked to the habits of populations and cultures. Often areas crowded by tourists run, of limited size such as bridges, must be considered in advance for emergencies. This article focuses on an old footbridge of Mostar located in a confined area with an increasing tourist flow. The peculiarity of the bridge lies in the double-flight geometry with elements that generate discontinuity in the trajectory as well as the steps. This analysis was carried out obtaining the traffic data from video cameras and analyzing different scenarios on holidays and weekdays. Also, the possible presence of obstacles on the bridge was taken into account, such as some areas not walkable for temporary work or the presence of obstacles. These scenarios have been calibrated and simulated through the definition of O/D matrices, arcs and nodes (or areas) through the pedestrian simulation tool Viswalk. This comparison is useful for understanding the variation of LOS (Level of Service) during the daily or emergency situations and the results can provide help to local authorities to plan and design an appropriate action plan. Therefore, this research work aims to compare scenarios under critical flow conditions in the order to define preventively possible actions that can guarantee an optimal LOS value during the bridge crossing and the surrounding areas