Minimum value toll

[FlaviaTsang]

Existing express lanes in the region charge users a minimum toll because operators need to recover operation costs.

From the information we gathered from the express lane operators(Asana task: https://app.asana.com/0/0/1206460470095669/f), the minimum tolls in the region are as follows:

• Express lanes operated by MTC: $0.50
• I-580 opened in Feb 2016 operated by ACTC: $0.30 (prior to 2017); $0.50 (since 2017)
• I-680 Sunol operated by ACTC: <$0.50 (prior to 2017); $0.50 (since 2017)
• Express lanes operated by VTA: $0.30 (always)

In the model, the minimum value toll is implemented in the highway skimming procedure. A number of other scripts are changed to propagate the new variable min_vtoll from params.properties —> runtimeconfiguration.py —> hwyParam.block —> HwySkims.job

This implementation is OD-based. The main caveat of this implementation is that it accepts only one minimum toll for all express lanes in the region. This caveat presents two issues:

• It impacts the year 2023 because different operators have slightly varied minimum tolls, whereas it does not affect 2015 since all operators have the same minimum toll.
• In practice, some trips may involve multiple facilities, resulting in the minimum toll being charged multiple times. This model may therefore underestimate the total cost that express lane users incur for these trips. Ideally, we would summarize how many persons/trips are in these situations. We haven't done so because of time constraints.

Neverthleless, it is worth noting that even with this limitation, the inclusion of a single one minimum toll for all express lanes in the region is an improvement over the absence of any minimum toll. It aligns more closely with how express lanes are priced and provides a better approximation of the actual costs borne by users.