I’m trying to use the shape_dist_traveled from stop_times to work out approximate trip distances and it seems like this doesn’t represent real life travel distances, as per https://developers.google.com/transit/gtfs/reference/.
For example - this is showing maximum trip distances for Mondays. There are a significant amount showing trip distances about 400km. When looking at some of the trips >800km, their real life distance is closer to < 200km. (I’m assuming shape_dist_traveled is measured in meters, so have already divided by 1000) .
Even when you take out regional trips, and only consider the Sydney Bus Network they’re still too high. Cross referencing those outliers (>400km), the real distance shown on the map should be closer to ~25km.
And then when you take those outliers above 200km out, there seems to be a divide between 10km and 100km values. When you consider Penrith -> Sydney CBD ~55km this has got to be wrong.
I don’t think this is just an issue of increasing error with increasing stop sequence as some 2nd stops jump from 0km to >20km in under 5 minutes (over 200km/hr!).
Hoping this is just my misunderstanding of what shape_dist_traveled can be used for, but would appreciate some clarification.