Development of a functional priority index for assessing the impact of a bridge closure

The paper moves from the recognition of the relevance of developing managerial tools and instruments for dealing with the progressive aging of civil infrastructures in a context in which resources for carrying out maintenance activities are shrinking. In order to contribute to the definition of the priority of intervention for the development of an adequate maintenance planning, the work proposes a functional priority index, that allows to rank the infrastructures based on the impact associated to their closure. The impact is expressed in terms of induced travel delay for people. To estimate this delay an analytical strategy is introduced and applied to assess a sample of 290 bridges in Lombardy. Relevant information are gathered through a data fusion approach, aggregating road network data and Origin Destination matrices. The results of this application show that the method is actually suitable for identifying the most critical infrastructures and, for each bridge closure, the most impacted municipalities of the region.