We present improved methods for computing a set of alternative source-to-destination routes in road networks in the form of an alternative graph. The resulting alternative graphs are characterized by minimum path overlap, small stretch factor, as well as low size and complexity. Our approach improves upon a previous one by introducing a new pruning stage preceding any other heuristic method and...

We examine the computation of optimal paths, which consist of using public transportation, walking and taking a car. A challenge in itself is to determine concise and diverse sets of paths. We consider metropolises like New York, where a fast computation of the paths is difficult. We exemplify that multiple optimality criteria are necessary to obtain diverse sets of paths. This extends the set ...

Models of planning under uncertainty, and in particular, MDPs and POMDPs have received much attention in the AI and DecisionTheoretic planning communities (Boutilier, Dean, and Hanks 1999; Kaelbling, Littman, and Cassandra 1998). These models allow for a richer and more realistic representation of real-world planning problems, but lead to increased complexity. Recently, a new approach for handl...

Three-dimensional (3-D) route-planning support offers a promising solution to overcome problems with wayfinding in complex indoor environments. An experiment was conducted to test the effect of 3-D route-planning support in a realistic setting, a large hospital building, during normal operation. Forty participants performed navigation tasks either with (n = 20) or without (n = 20) 3-D route-pla...