road preference

[jzvc]

Think there are some wrong settings for road vs distance preference.

http://www.openstreetmap.org/directions?engine=osrm_car&route=50.5810%2C13.9268%3B50.5771%2C13.9287#map=17/50.57886/13.92983

[DennisOSRM]

We have a number of issues on this problem. It essentially boils down to having some model that gives the penalties incurred by leaving a road to take shortcuts on somewhat less important roads.

[TheMarex]

However we should send a note to the OSM people because they seem to always pass z=14 which causes the DP to be a little bit aggressive in this case.

[DennisOSRM]

However we should send a note to the OSM people because they seem to always pass z=14 which causes the DP to be a little bit aggressive in this case.

Already done.

[jzvc]

For sure, it's not about map zoom, it's about Route>

Distance: 0.29 km
Duration: 21 s

Head southeast onto 8 55 m
Turn slight right 54 m
Turn slight right 0.11 km
Turn slight left 29 m
Turn slight right onto 8 43 m

VS

Distance: 0.31 km
Duration:22 s

Head southeast onto 8 0.14 km
Reaching intermediate destination on 8 0.16 km

(from http://map.project-osrm.org/ with 3rd point for enforcement)

When someone want use that in unknown locality...
Maybe some sort of time/length penalization on road type can work? Say +30% for streets and little less for tertiarry/secondary/? And/Or some penalty for turns?

For that little example, when I use 1s (and in real, this is not possible) for turn, then I have not 21s vs 22s, but 25s vs 22s.

[TheMarex]

The only way to fix this is using a turn penalty. This is tracked in #477