Questionable travel time calculation

[airbreather]

The route calculated with the same program seen in #267 seems to have the correct distance, but the reported travel time of 254 minutes feels unusually high.

Here are what some other providers calculate for the same route:

Provider	Reported travel time
Project OSRM	175 minutes
Google	168 minutes or so
Bing	206 minutes with traffic

Is there something we can learn from Project OSRM's own car profile?

[airbreather]

Another sample route that seems way too high (reported application timing values are low because I'm using a custom IArrayFactory that creates NativeMemoryMappedArray<T> instances backed by files in a temp folder that I manually clear out, so that I don't have to micromanage my page file as much):

    // replace these in Program.cs:
    const float SrcLat = 42.329434f;
    const float SrcLon = -83.038549f;

    const float DstLat = 33.806898f;
    const float DstLon = -118.146133f;

Loading router DB from disk... done after 13.176 seconds.

Starting calculation for car (not contracted)... done after 401.520 seconds.
    GeoJSON: << REDACTED, see attachment >>
    Total distance: 2,480.597 miles
    Total time:     2,735.515 minutes

Same kind of table as above:

Provider	Reported travel time
Project OSRM	2,100 minutes
Google	1,980 minutes
Bing	2,431 minutes with traffic

Route GeoJSON: route.txt