D tour at motorway junction over motorway_link, wrong, time/speed calculation problem?

[AllroadsNL]

Situation link OSM site Situation link OSRM site

Image situation:

Espected: That the motorway was taken straight on.

Failure: The D tour is taken over the motorway_link.

Data is changed recently because of Government maxspeed rules on motorway. (nation wide) motorway: maxspeed=100 maxspeed:conditional=130 @ (19:00-06:00)

But on the motorway_link to the motorway situation streetview there is this G01 trafficsign

This means from that point, rules says you can drive 130. And Government did not adjust that, Once directly on the motorway, we get mostly a trafficsign with maxspeed=100 maxspeed:conditional=130 @ (19:00-06:00), because there is a other junction comming up, in this case, there is only a maxspeed=100 sign. Stituation streetview.

Maybe for this type of situations, with a motorway_link. where the maxspeed is higher as the motorway, where a D tour is visualised wrongly a other time/speed calculation should be used?

There is also highway=give_way on the exit motorway_link, that does not have the effect as it should have. To better calculate the time/speed ratio?

General: At a give_way, people come mostly to a stop, so this effect the time/speed ratio. At a entrance motorway_link, people have to accelarate mostly, this should effect the time/speed ratio.

Or is the program struggling with the conditional settings?

The data in OSM is correct, a situation, that now is common in the Netherlands. The Government, says, because of the entrence of a motorway, people mostly drive/ride not that 130 maxspeed, must accelerate, because it is a entrance. More trafficsigns, does not make the road safer. After a couple of hunderd meters they get the new maxspeed sign. It is a consideration of more trafficsigns, costs and safety risks.

[danpat]

The core problem is that there's no penalty for the give-way on the motorway_link - the router is assuming you can drive 100km/h onto the exit, then 130km/h to re-enter the motorway. It thinks this is faster than just taking the shorter motorway directly at 100km/h (maxspeed:conditional is not used by OSRM).

One change that could be made would be to include highway=give_way nodes in the traffic_light_penalty (https://github.com/Project-OSRM/osrm-backend/blob/master/profiles/car.lua#L29) - this would add some time/cost to the road crossing to better align things with reality.

[AllroadsNL]

A motorway_link, in general is a part of the road system, where you accelerate to merge in to the motorway or exit decelerate. Although a motoway_link has a maxspeed tag, we have to take in mind the acceleration/decellerate proces as a part of the traffic behaviour.

Acceleration, means, a average speed on that part of the road.

Adding some time/cost to the motorway link, could be a good idea, mostly these roads are curved, merge/exit behaviours, from other roads.

Sometimes extra speed traffic signs with a low speed. say 70 or less are placed. For saftey reasons. Normally, then above 70, a time/cost must be taken in account. to level out the accelerate/decelerate.

Average, can not be expressed by a maxspeed:pratical tag, such tags is for the whole road, on every part you can drive/ride. There is not a Government maxspeed advised sign.

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[AllroadsNL]

This problem is not solved, the D route is still like topic first post.