[openstreetmap-website] OSRM: Zoom level 14 causes loss of precision for very close-by locations (#1077)

[mmd]

Please compare the following two OSRM routing results for the same start/end location:

* [OSRM routing result on OSRM project site](http://map.project-osrm.org/?z=18&center=51.859235%2C6.499635&loc=51.859563%2C6.500167&loc=51.859387%2C6.498863&hl=en&ly=&alt=&df=&srv=)

* [OSRM routing result on OSM web site](http://www.openstreetmap.org/directions?engine=osrm_car&route=51.85956%2C6.50017%3B51.85939%2C6.49886#map=19/51.85923/6.49963)

Issue: while the OSM website calls OSRM router with zoom level 14, the OSRM project site on map.project-osrm.org calls the OSRM router a second time with zoom level 18. By using zoom level 18, the routing results look more reasonable and in this specific case avoid a navigation right through a playground via car.

If you watch very closely, map.project-osrm.org actually triggers 2 routing calls: one with zoom level 14 (?) and a second one with zoom level 18. I guess this additional step is somehow triggered if objects are very close to each other. I would assume that a similar logic needs to be put in to place on osm.org as well, to get similar results.

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Reply to this email directly or view it on GitHub:
https://github.com/openstreetmap/openstreetmap-website/issues/1077
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