Match service only performs half the way (ignore start/finish points?)

[paro-]

Hi OSRM folks,

Request 1 does not finish at the destination (last coordinate in the request) and 2 does not start at the first given coordinate.

Granted my GPS data is kind of clustered but I would have thought that the start & finish points could not be ignored (treated as outliers?). Is there a way to force them please, or to get the full route somehow?

I can provide screenshots if helpful.

Thanks a lot, Paul

[danpat]

Screenshots are helpful, they reduce the work other folks need to do to understand the problem.

In the API response, I can see the last two coordinates have null tracepoint entries - this means they weren't matched.

Looking at the screenshot, it's likely because the spacing between the 3rd-last and second-last coordinates is too far. Overall, this trace is much sparser than I think is really useful in this kind of road network density to give good results - there are way too many alternative routes between the widely spaced coordinates, the routing engine simply can't decide which one was the right way, - it's too ambiguous.

Overall, I don't think you can expect good matches on sparse data like this, in areas where the road network is this dense - it's an unreasonable expectation.

[kaligrafy]

I have the same problem whice doing path calculation for buses. It worked well before version 5.26 I think and now it fails with similar paths using motorways for long segments. Has anything changed in the matching algorithm since version 5.25?