Approximating Shortest Path in Large-Scale Road Networks with Turn Prohibitions Using Multi-constrained Path Algorithm

Multi-Constrained Path (MCP) algorithms are path finding algorithms, unlike conventional routing algorithms, they not only give a path between source and destination, also verifies whether the path satisfies the given constraints (Right turn, Left turn and U turn). MCP algorithms are NPComplete. The MCP algorithms are aimed to find the shortest path in a road network that satisfies the turn prohibitions and has many applications such as route guidance in Intelligent Transport System (ITS). In this paper, roads are considered as nodes and junctions as edges, as it reduces the amount of data to be processed. The output consists of a list of paths that can be used to reach the destination. The algorithms have be tested and analysed with the real data of Bangalore road network. The results show that the efficiency of MCP is 84.5% better than conventional routing algorithms in terms of execution time.