A Survey on Optimal Route Queries for Road Networks

Abstract

In daily life the need to find optimal routes between two points is critical, for example finding the shortest distance to the nearest hospital. Internet based maps are now widely used for this purpose. Route search and optimal route queries are two important classes of queries based on road network concept. Route search queries find the route according to the given constraints. The optimal route queries find the optimum route from a set of specifications by a user. In road map queries, users have to give the specification of starting point and ending point of their travelling with or without constraints. Some spatial features about the categories and the different locations should be specified along with this. If the travelling constraints are given then it should be unique. These constraints may be either total order or partial order. In this specification order there should be information about both starting point and destination point of the travelling. The optimal route queries optimize the possible routes and give the optimal route that satisfies all the constraints. This paper describes the survey on optimal route query processing, two categories namely optimal route query processing and spatial search with categorical information have been considered, a discussion on technique for optimal route query with constraints and without constraint is also included. The total order needs a specification of list of points and in the same order that they should be visited but that is not required for partial order constraints. Finally this paper concludes with pros and cons of different techniques under optimal route queries.