Routing with search radius as waypoints

[kaligrafy]

I am building a genetic algorithm that creates transit bus routes using a list of predetermined stops. The algorithm has to try a lot of stops combinations to create optimal routes. The problem is if stops are placed away from the intersection, the routing results can create detours like shown on the first image (U-Turn are disabled for bus routing in my lua profile):

However, if the stop is placed just a bit on the right, the result is correct and optimal:

As mentioned in #930, would it be possible to search for the shortest path using all phantom nodes inside a circle? By instance, I give a location for the stop as a waypoint, than I choose the maximum radius using radiuses properties (say 100m), and the routing engine will find the best route inside the circle and ignore detours like the first image. In fact, the exact stop sign location would then be selected using the result output by the router. By the way, I cannot use bearings since the algorithm doesn't have a clue from where and to where the route is going before doing the routing.

Thanks for any help on this.

[TheMarex]

Try using the map matching /match/v1/driving/{first};{second};{third}.json?radiuses=100;100;100 should basically give you exactly what you want.

[danpat]

Note that by default, the match plugin might split the result if the coordinates are > 2000m apart, but otherwise @TheMarex is right, that's probably the simplest way to get what you want.

@kaligrafy For your example - is there only one bus stop? Are you expecting the person to get off the bus at the intersection, cross the road, and get on a new bus line ?

[kaligrafy]

@danpat The bus stop is not defined precisely, the algorithm tries multiple bus routes created by ordering a list of approximate stops to find optimal routes. After this process, the exact stop sign location can be determined for each route according to directions. I'll try the map matching, thanks!

[kaligrafy]

Thanks it works perfectly! I just forgot that map matching returned duration and distance too, not just the matched path.

[TheMarex]

Perfect! 👍

[kaligrafy]

Just a question about this, how can we disable u-turn when matching? I disabled u-turns in the lua profile, but the matching response sometimes returns a path with u-turns. Is it possible to force a route with no u-turn?

[danpat]

@kaligrafy no, there's no parameter exposed to do that. The route service has continue_straight, but that's not available for match.

[kaligrafy]

There is another problem I just faced: I need to force the matching to pass in the radius of every points (these are the bus stops). Sometimes, the routing ignores some points when there are too far apart, but I would need it to keep them even if the confidence stay low. Is that possible?