Toll Scenarios

Toll Scenarios

We coded two separate toll scenarios with several toll cost variations within each scenario. The Columbia River Bridge Toll Scenario involves tolling the I-5 and I-205 bridges spanning the Columbia River. Three sets of daily bridge tolls ($1, $5, and $10) were coded in order to assess model elasticities. Tolls were coded in both directions and for both passenger vehicles and trucks. The Portland-to-Salem I-5 Toll Scenario tests per-mile tolls on I-5 between Portland and Salem from the I-5\I-205 split to 99E just north of Salem (approximately 28 miles of freeway). Again, three levels of toll will be tested ($0.10\mile, $0.20\mile, $0.40\mile, roughly equaling $2.80, $5.60 and $11.20 per one-way trip between Portland and Salem). As per the bridge scenario, tolls do not vary by time-of-day day or vehicle type for the sake of simplicity. In both scenarios, tolls are introduced in the 2020 (t30) transport networks and remain constant through subsequent years.

Setting up the scenarios

Generally, adding tolls to links involves editing the VISUM version file for the year or years that the toll will be applied. Each link where a toll is to be applied is opened and a daily toll is entered for the link. The network does not currently support tolls that vary by time-of-day. All toll costs are in dollars.

Portland-to-Salem I-5 Toll Scenario

1. Set up a new model scenario "toll_pdxsal_10cpm" for tolling between Portland and Salem at 10 cents per mile.

2. Create a new t30 directory in the inputs folder and copy the VISUM version file from t0 into t30. This assumes that facilities will be tolled starting in 2020.

3. Open t30 VISUM version file and create a filter set to Plan No. = 1 or 11 to highlight freeways. This is helpful to focus on I-5.

4. Select I-5 links between Portland (I-205) and Salem (Salem Parkway) and set the auto and truck toll fields (Toll_PrTSys(a) and Toll_PrTSys(d)) to 0.1 for 10 cents per mile.

5. Create another link filter for toll fields = 0.1 and confirm that they have been set correctly.

6. Copy "toll_pdxsal_10cpm" to another scenario "toll_pdxsal_20cpm" for tolling between Portland and Salem at 20 cents per mile.

7. Open t30 VISUM version file and create a filter set to Toll_PrTSys(d) = 0.1 to select the tolled portion of I-5 from the copied scenario.

8. Use VISUM multi-edit to change Toll_PrTSys(a) to constant value 0.2 for all selected links. Repeat for Toll_PrTSys(d).

9. Change link filter to Toll_PrTSys(a) = 0.2 to make sure it worked.

10. Repeat steps 6 through 9 for a new scenario "toll_pdxsal_40cpm"

Columbia River Toll Scenario

1. Set up a new model scenario "toll_bridge_1dollar" for tolling bridges at $1 each way.

2. Create a new t30 directory in the inputs folder and copy VISUM version file from t0 into t30

3. Open t30 VISUM version file and create a filter set to Plan No. = 1 or 11 to highlight freeways

4. Select I-5 links on Oregon\Washington bridge and set toll fields (Toll_PrTSys(a) and Toll_PrTSys(d)) to 1.0. Repeat this step for I-205 links on Oregon\Washington bridge.

5. Repeat steps 1 through 4 for "toll_bridge_5dollar" and "toll_bridge_10dollar".