Incorrect matching of ScheduleStopPairs to route geometry

[kylebarron]

There are multiple instances (that are clear to see visually) where the transit vehicles are moving way too fast. For example, look at this on the loop in Chicago:

Notice how there are super long tails around the loop? That's from schedules that are incorrectly matched to routes.

I did some digging here, using the Brown line metro. Take a look at this ScheduleStopPair:

{
  "origin_dist_traveled": "546.2",
  "origin_onestop_id": "s-dp3wspsmsk-kedziebrown<30226",
  "route_onestop_id": "r-dp3w-brownline",
  "trip": "59151270686",
  "origin_timepoint_source": "gtfs_exact",
  "destination_dist_traveled": "1140.6",
  "route_stop_pattern_onestop_id": "r-dp3w-brownline-a3d334-f6e93f",
  "destination_timepoint_source": "gtfs_exact",
  "destination_onestop_id": "s-dp3wsr9tgt-francisco<30168",
  "destination_arrival_time": "17:49:00",
  "origin_departure_time": "17:48:00",
  "speed": 301.5832166384404,
  "dist": 18094.99299830642
}

(with operator id: o-dp3-chicagotransitauthority)

Here's a visualization of how I'm currently matching that to a route:

The two neighboring stops are in the top left. But since this is a loop route, the second stop is getting matched to the route on its way back. So it's assigning an 18km route between stops that are a minute apart.