Demand/Automatic Routing

There is another approach to vehicle routing which may be adequate in the following situations:
 * there is not enough time / computing power to wait for the dynamic user equilibrium
 * changes to the net occur while the simulation is running
 * vehicles need to adapt their route while running

In this case SUMO may be used directly for routing with either routes or trip files (or a mix) as input. The options related to this routing are: If the routing is enabled for selected vehicles (either with the ".probability" or the ".knownveh" option), the average travel times in the net are collected for all edges. If a vehicle needs to be routed (either because it gets inserted or because a repeated route choice was enabled via the ".period" option) it chooses the shortest route to its destination edge (or district) according to the present edge weights (travel times). The update of the edge weights does not simply overwrite the old value but gives it a certain weight which may be modified with the ".adaption-weight" option. Since updating the weights of all edges in each simulation step means a major slowdown for the simulation this interval may be altered using the ".adaption-interval" option.