EMBARQ report points to need to reduce Vehicle Miles Traveled per capita in the US to meet emission and oil consumption targets; “sustainable VMT”
|Summary of Sustainable VMT per Capita in 2050, compared to 2010 levels, under the eight scenarios analyzed in the report. Data: EMBARQ. Click to enlarge.|
A report released earlier this summer by released by EMBARQ—the World Resources Institute’s Center for Sustainable Transport—found that the US must achieve significant improvements in vehicle technology and reduce vehicle miles traveled (VMT) per capita to meet targeted reductions in oil consumption and greenhouse gases.
The report, “The Role of Driving in Reducing GHG Emissions and Oil Consumption: Recommendations for Federal Transportation Policy,” introduces a concept which the authors term “sustainable VMT”—an indicator of the amount of light-duty vehicle (LDV) travel per capita that can occur without compromising the goals of reducing GHG emissions and oil consumption.
The authors analyze eight transportation scenarios through 2050. Each scenario consists of one set of vehicle technology assumptions, one set of assumptions regarding either GHG emissions reductions or oil savings over time, and a corresponding projection of sustainable VMT per capita. There are two distinct sets of vehicle technology assumptions: “moderate” and “optimistic.”
The authors pairing each of four oil use and GHG emissions reduction targets with the two sets of vehicle technology assumptions to calculate the maximum change in VMT that can occur, relative to 2010, without exceeding the targeted level of oil consumption or GHG emissions. This maximum change in total VMT is then translated into sustainable VMT per capita, assuming an annual population growth rate of 0.9%.
They found that changes in VMT per capita to achieve the targets range from -77% (Early Bird GHG reductions paired with Moderate Technology changes) to +32% (Minimal Oil Imports in 2030 paired with Optimistic Technology).
In every scenario, even under optimistic technology assumptions and the less aggressive oil use and GHG emissions reductions, the United States will need to moderate per capita VMT relative to BAU projections. BAU projections predict VMT approximately 40 percent above 2010 levels in 2050. This is a plausible projection, because VMT per capita has increased by approximately 76 percent since 1970. Recently, however, the growth rate for VMT has slowed, even declining since 2005 when calculated per capita. Thus, BAU predictions may overestimate future VMT levels.
Even with the optimistic assumptions about vehicle technology, three out of four scenarios show that VMT per capita must stay at, or decrease below, 2010 levels by 2050. The exception is the Minimal Oil Imports plus Optimistic Technology scenario, under which an increase in VMT per capita (compared to 2010 levels) is possible due to a large share of vehicle electrification, which reduces oil consumption. It is important to note, however, that an increase in electric vehicles does not achieve GHG emissions reductions equivalent to the magnitude of oil use reductions unless there are near-zero emissions from the grid that fuels these vehicles.—“The Role of Driving...”
The report also reviews evaluations of existing federal transportation programs for their impact on GHG emissions, oil use, or VMT and finds a general lack of evaluation for these metrics. For a wide variety of transportation strategies (e.g., public transit, pricing, parking management), the report finds evidence that they reduce GHG emissions, oil use, and VMT.
Our analysis illustrates that with decisive action, it is possible for the US to significantly reduce GHG emissions and oil consumption from transportation. The analysis suggests that achieving these goals will likely require both significantly improved vehicle and fuel technologies, as well as a reduction in the number of miles Americans drive. It is clear that neither technology improvements nor driving reductions are likely to be sufficient on their own, which should inform the upcoming discussion of U.S. federal transportation priorities.—lead author Allison Bishins
To achieve GHG emissions and oil use targets, the report says, the United States should modify federal transportation policy to prioritize investments that reduce VMT, GHG emissions, and oil consumption. According to the report, the US Department of Transportation (DOT) should:
Encourage states and regions to boost usage of existing funding flexibility to increase investments in transportation strategies that reduce VMT, GHG emissions, and oil use;
Provide technical support for standardized evaluation of programs and projects; and
Simplify public access to DOT’s project spending databases to promote evaluation of spending patterns and encourage transparency and accountability.
Congressional reauthorization of surface transportation funding should:
Establish national goals for transportation, including reducing GHG emissions and oil use, and track progress toward these goals.
Implement performance-based funding (tied to progress toward national goals). Require or incentivize performance-based planning. Reserve or competitively distribute funding for states and regions that plan for GHG emissions reductions and/or oil savings.
Increase direct funding for programs and strategies that reduce GHG emissions, VMT, and oil consumption, in two ways. First, direct a larger portion of federal transportation funds toward programs that dedicate funding to, or achieve, reductions in GHG emissions, VMT, and oil use (e.g. CMAQ, SRTS, etc.) Second,
Directly fund transportation strategies that reduce VMT, GHG emissions, and oil use through set-asides or new programs.
Although the rate of progress in transportation technology is uncertain, these improvements are encouraged by federal incentives and standards. Similarly, the United States can ensure reductions in VMT, GHG emissions, and oil consumption by planning for and funding transportation and land use strategies that provide alternatives to driving. Transportation planning at the local, regional, and state level should incorporate strategies to reduce VMT in order to reduce GHG emissions and oil consumption.
Planners and policymakers committed to reducing oil use and GHG emissions should encourage Congress to pass a reauthorization bill that incorporates the recommendations above, the report concludes.