Auto Operating Cost Assumptions - tlumip/CALM GitHub Wiki

Background

JEMnR has a handful of ways to introduce income and travel cost inputs into the model; transit fares, parking costs, household income levels, and a global (fleet level) auto operating cost assumption. ODOT still relies on a 1995 Joint Estimation completed for the State of Oregon. Because of this, all cost inputs in JEMnR need to be deflated back to 1995. At the time of estimation, the observed Auto Operating cost was $0.091/mile (1995 dollars). This value captures (represents), fuel and the maintenance costs to operate a motorized personal vehicle, and has been used unchanged for the majority of the last ~20 years. However, Oregon and the nation are currently at the beginning of a large paradigm shift in how travelers will pay per mile. An ever increasing shift to Electric Vehicles (EVs) can be seen happening across the globe, but with specific and faster shifts on the West Coast of the United States (including Oregon). The shift to EVs is anticipated to bring down the average cost of travel by mile. Currently EVs have a higher upfront investment cost (sunk cost), but a lower per mile cost. That upfront sunk cost is not reflected in the auto operating cost per mile. Sunk costs would show up in something like a mileage reimbursement value, which is different then the per mile cost to operate a vehicle that does not include the sunk costs.

For these reasons, it becomes increasingly important to re-evaluate and properly establish the auto operating cost assumption in both the base and future model years (as so much change in that input is anticipated to occur over the planning horizon). The remainder of this page documents how the auto operating cost input to JEMnR has been re-assessed and re-established.

2010 and 2020 Costs Revaluation

2010 was a specific year of note related to model development in Oregon. Specifically 2010 was the last time a larger travel survey was conducted in Oregon, allowing multiple Oregon models to re-assess and re-establish their model estimation and calibration. Portland Metro specifically re-estimated and re-established their trip-based model in 2010. At that time they found that the auto operating cost assumption was $0.211/mile (2010 dollars). Recently, Portland Metro reviewed these costs for their latest 2020 RTP base year, and found that the 2010 assumption was still largely the same $0.208/mile (2010 dollars).

Alongside Metro's model re-estimation in 2010, ODOT also re-established SWIM in 2009/2010 and borrowed an 2010 estimation for the Southern Oregon ABM (SOABM), and further, heavy work around GreenSTEP and VisionEval was also being established during this same time. All three of these efforts; SWIM, SOABM, and GreenSTEP/VE, landed on a value of $0.18/mile (2010 dollars). This is documented in much greater detail on the SOABM wiki.

In reviewing this information, the decision about whether to use $0.18/mile or $0.21/mile (2010 dollars) is put before JEMnR. In looking into Metro's latest 2020 work, it was found that they used a slightly different deflator value then the one that ODOT has adopted to use. Metro was utilizing the BLS CPI calculator, where as ODOT has tried to stay aligned with DAS OEA assumptions, which uses the CPI for the western region. When the Western Region CPI is used, the 2020 metro work returns a value of $0.19/mile (2010 dollars). Clearly, 0.18 and 0.19 are very similar, and there's significantly less of a decision to be made in this case as to which to use. Use the Western Region CPI, a factor of 0.69 takes 0.19 back to 1995 at a value of $0.13/mile (1995 dollars), which is the proposed way forward for JEMnR for the 2019 base year models currently in the process of being finalized.

Future (Planning Horizon) Cost Assumptions

To-date, the VisionEval and related GHG Monitoring work that ODOT has undertaken has completed the most comprehensive assessment of what the future cost per mile values might be, and are the best available information for these future year assumptions. The work to compare the VisionEval assumptions are documented on the SOABM wiki. The work documented there results in a comparable auto operating cost value of $0.114/mile (2010 dollars), which deflates to ~$0.08/mile (1995 dollars) using the deflator of 0.69.

Summary Findings and Recommendations

ODOT's JEMnR instance still relies on a 1995 estimation, and therefore all dollars need to be in 1995 dollars. For the 2019 base year, ODOT models should strongly consider using a value of $0.13/mile (1995 dollars). For a planning horizon future year (like 2045 or 2050), ODOT models should strongly consider using a value of $0.08/mile (1995 dollars) for the reference/official scenario (other values can be used as sensitivity tests around this value).