Bridge prioritization in urban road network traffic performance Case study: Transportation network in the City of Isfahan

Urban transportation network is an essential component of our daily life in modern communities. This network is vulnerable to natural and humanitarian disasters. Its degradation may lead to large negative impacts on the economic efficiency of the community. Repair and maintenance of highway bridges, as the most critical component of the network, comprises a large portion of total annual maintenance costs, and usually due to lack of unlimited budget, this money has to be spent based on the importance and/or priority of the bridges in the network. The current study aims to prioritize the critical bridges during normal traffic conditions in an urban transportation network. The rank of each bridge is based the difference in the total network travel time before and after that given bridge is eliminated from the network. The bridge that by its elimination causes higher travel time is considered more critical. Proper functioning of bridges in the city of Isfahan, through which Zayande-Roud river passes, is quite important. This proposed method is applied to 78 bridges in Isfahan traffic network. Comparing the result of this method with the ranking of the highest traffic volume bridges demonstrates that critical bridges are not necessarily the ones with the highest volumes. In other words, the importance of a bridge or a link in the network is more dependent on the number of substitute detours, when that bridge/link is closed, than the traffic volume of that bridge/link.