State DOTs are key players in cutting transportation emissions

By Chris McCahill and Megan Link

Through a combination of carrots and sticks—but mostly carrots—the federal government has encouraged state DOTs to take ambitious steps to lower the environmental impacts of transportation and to invest in more sustainable travel options. Two years into the Bipartisan Infrastructure Law (BIL), notes Adie Tomer at Brookings, it is still hard to know the impacts. Many states are still operating under the status quo. Others, however, including many SSTI partners, are seizing the opportunity to bolster ongoing local sustainability initiatives. 

Federal landscape

Recently, USDOT issued a rule aimed at tracking and reducing greenhouse gas emissions. The new rule requires state agencies and metropolitan planning organizations to establish targets for lowering carbon emissions on the National Highway System and to report progress every two years, beginning in 2024. By producing public-facing emissions data, the rule increases transparency regarding the impacts of transportation investments. Some states have pushed back, but others embraced the law. Ten states—all SSTI partners—signed a letter welcoming the law last year. Connecticut DOT Commissioner Garrett Eucalitto, an SSTI advisor and recent Community of Practice host, commended the new rule: 

“We can’t improve what we don’t measure. The final rule will guide our agency’s work in eliminating greenhouse gas emissions to reduce the impacts of climate change. CTDOT is proud to support this final rule and will continue to collaborate with FHWA and our peer state DOTs to reduce our state’s GHG emissions.”

The new regulation, paired with targeted federal funding programs issued under the BIL, reinforces work that is already underway in many states. Most states, for instance, recently submitted their carbon reduction strategies, a requirement to qualify for the federal Carbon Reduction Program. Based on discussions among SSTI’s sustainability network, those plans include a combination of high-level strategies and specific project lists, although federal specifications were not entirely clear.  

What is clear, however, is that several states had an advantage in fleshing out those strategies, since some have been targeting transportation emissions long before the BIL. Two new reports—one from RMI and another from NRDC—offer some indication of how far along some states are, compared to others.  

State-led initiatives

Prompted in large part by the National Electric Vehicle Infrastructure (NEVI) program, every state is preparing to ramp up its EV charging capacity. Several states, however, are also targeting vehicle miles traveled (VMT) as a key pillar in achieving emissions and climate goals. An earlier analysis by SSTI showed how important future VMT trends will be in meeting ambitious climate goals, depending on other factors like vehicle efficiency and rates of electrification. Lowering VMT has other added benefits that include congestion relief, improved health and safety, and cost savings.  

Colorado approved a new planning standard late in 2021 requiring state and regional plans to meet greenhouse gas targets, or else transportation funds can be redirected to low-carbon investments. The rule does not set explicit VMT targets, but it could lead to a 6%-9% reduction by 2030, according to the Southwest Energy Efficiency Project. The Colorado DOT subsequently halted two planned highway projects in the Denver area and the state’s Transportation Commission approved a 10-year plan that shifted some of those funds to transit and other operational improvements. A recent analysis by RMI, however, suggests the state is only on track to achieve 41% of the required reduction in transportation emissions by 2030.  

California has been on a longer journey, marked by the passage of SB 375 in 2008 and SB 743 in 2013. The latter requires a shift from level of service (LOS) to VMT in measuring the environmental impacts of transportation investments. Since its implementation, Caltrans along with other state and local agencies have been working toward better tools for estimating and mitigating the VMT impacts of highway investments. SSTI has been working with Caltrans and researchers from UC-Davis to develop and implement new analytical tools, including accessibility analysis. 

Both states were featured in a SSTI webinar last year. 

Minnesota boasts one of the newest and most wide-ranging pieces of legislature targeting transportation emissions. The law includes at least $600 million in transit funding and tax credits for e-bikes. MnDOT Commissioner Nancy Daubenberger was “less happy about a number of highway projects that are directed in the bill—earmarks,” according to reports. Before the landmark bill passed, the agency had already set an internal VMT reduction target of 20% per capita by 2050 and released a Statewide Multimodal Transportation Plan earlier this year bolstering that objective. SSTI has collaborated with MnDOT in conducting both a statewide field scan and leading internal focus groups to chart a path toward meeting its ambitious VMT goals. 

In support of these initiatives, SSTI launched its own sustainability network early in 2023, following a successful year-long climate policy cohort. The network is designed as a peer-exchange to support DOT officials through monthly virtual sessions and a listserv. As states work toward implementing new federal and state initiatives aimed at carbon reductions and emissions tracking, the opportunity to share lessons learned and best practices among the states has proven invaluable. As we look toward the next year, Georgetown Climate Center, our new partner, is helping to advance the network. 

Photo Credit: Josh Hild via Unsplash, unmodified. License