🐛 Bug: `trip_dist` in CT-RAMP Output Trip List Does Not Match Distance Skims

[i-am-sijia]

Describe the bug

We noticed this issue during MAZ assignment. MAZ assignment complains that there are vehicle trips longer than our pre-defined distance threshold for MAZ assignment, which should not happen.

We use the trip_dist column from the CT-RAMP trip list to select trips that are subject to MAZ assignment. It turns out that trip_dist is inaccurate. The screenshot below shows the EA vehicle trip table for MAZ assignment, where MAZ_x, MAZ_y, orig_taz, dest_taz, trip_dist, eq_cnt, taz_distance are the origin MAZ, destination MAZ, origin TAZ, destination TAZ, trip_dist from CT-RAMP trip list, number of vehicle trips, and lastly, the distance skim from highway TAZ skims. You can see that there are a couple of OD pairs with large discrepancies between the trip_dist and the highway distance skim.

We should investigate deeper:

1. How is trip_dist created and why doesn't it match skims?
2. Whether trip_dist is used in CT-RAMP, and if so, any implications? It's used by tm2py only in MAZ assignment.

Progress:

• Sufficient information provided
• Cause identified/found
• Test developed/identified
• Approach determined
• Test passes

To Reproduce

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Failing tests

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Triggering line of code

Thoughts on resolution

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Environment

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