About Fast Costing Switches

Fast Costing is performed by the Schedule Server to quickly evaluate a group of candidate solutions and select the best ones to present to the user when scheduling a client trip.

Using a combination of triangulation and street routing, Fast Costing avoids performing expensive (that is, time-consuming) solution evaluation using street routing or barrier calculations by evaluating only a user-defined number of solutions.

During the Fast Costing process, solutions are calculated using triangulation. If the top solutions have no violations, they are re-costed using street routing. This pre-filtering phase saves time because using street routing on all candidate solutions slows down the search process for trip solutions.

Note that Fast Costing must be set up such that triangulation and speed factors best reflect actual street routing speeds:
  • If triangulation is too fast, many inadequate candidate solutions are re-costed only to find that they are too slow or do not result in valid solutions.
  • If triangulation speeds are too slow, then few to no solutions are re-costed.