The current U.S. Highway Code does not have a single performance measure that focuses on the reduction of greenhouse gases or vehicle miles traveled, but a new bill in Congress aims to establish a connection and incentivize reductions.
Why it matters: Transportation contributes 28% of U.S. greenhouse gas emissions. Driving represents 83% of trips, and the number of miles driven is rising, posing a serious problem to curbing emissions.
What's happening: U.S. transportation funding typically prioritizes roadway expansion projects, which can reduce congestion, at least temporarily, and increase speeds.
- Yes, but: Building and widening roads actually encourages more people to drive.
- The Federal Highway Administration reports that vehicle miles traveled (VMT) is increasing: U.S. driving topped 1.58 trillion miles in the first half of 2018, 5.2 billion miles more than the same period the year prior.
- Without making the reduction of VMT a clear goal built into transportation funding, this trend is likely to continue.
What's needed: A best case scenario would be for the federal government to establish a GHG emissions reduction goal for the national transportation plan.
- Proposed projects on the federal, state and city levels would need to align with that goal to receive funding.
- States and regional agencies could eventually be required to share a project’s performance as it relates to VMT and emissions.
What to watch: The GREEN Streets Act, introduced in July, lists combating climate change among its goals. Among other items, it would direct the transportation secretary to establish minimum standards for states to reduce GHGs on the National Highway System.
- If passed — which is uncertain in this Congress — this bill would connect transportation and climate change via federal funding for all states.
Tiffany Chu is the COO and a co-founder of Remix, which helps cities plan transportation networks, and a commissioner at the San Francisco Department of the Environment.
