LAUSR

The challenges in evacuation planning have been vital because of rapid disasters and limited road capacity. Contraflow strategy is very effective and widely accepted approach for the optimal use of available road network in evacuation management that increases the outward road capacities from the disastrous areas towards the safe destinations. Modeling the contraflow problem mathematically, there are available a number of efficient solution algorithms in literature, however, in general, the problem is still computationally quite hard. In this paper, we introduce the partial contraflow approach, in the abstract network setting with flow on paths and adapt the previous contraflow solution techniques to save unused capacities of road segments (elements) which can be used for supplying other facilities during emergency. We present efficient algorithms to solve the maximum static, lex-maximum static, maximum dynamic and earliest arrival partial contraflow problems on an abstract network. We also present an approximation algorithm to solve 2-value approximate earliest arrival transshipment partial contraflow problem for multi-terminal abstract network. Implementation of the partial contraflow reconfiguration leads to a significant improvement in increasing the flow values, decreasing the evacuation time, and utilizing the unused capacities of paths for humanitarian logistics and vehicle movements.