Only Four States Have VMT Mitigation Laws, But Maryland’s Refiled Bill Raises the Threshold to $100 Million

Only four U.S. states currently mandate Vehicle Miles Traveled (VMT) mitigation, requiring transportation projects to assess and offset increased driving. Maryland’s refiled bill, however, raises the cost threshold for such assessments from $5 million to $100 million, potentially limiting its reach.

Vehicle Miles Traveled, or VMT, quantifies the total distance vehicles travel within a specific area. For decades, increased VMT was often seen as an indicator of economic progress. However, this perspective has evolved. Today, higher VMT is increasingly linked to escalating household expenses, worsening traffic congestion, and greater greenhouse gas emissions. Governments and transportation planners now actively seek solutions to improve mobility and access without simultaneously increasing the overall miles driven. VMT mitigation strategies represent one such approach, aiming to manage these impacts directly.

Only four states currently operate under VMT mitigation laws: California, Minnesota, Colorado, and Oregon. These state-level mandates require transportation officials to assess how proposed projects might influence VMT. If projects are projected to increase driving, these laws often compel mitigation measures to offset those increases, sometimes by funding alternatives to driving.

Colorado provides a clear example of VMT mitigation in action. Its state law directed a substantial reallocation of public funds. Specifically, Colorado moved $900 million from planned highway expansions. These funds were then redirected to invest in bus rapid transit lines and other public transportation improvements, aiming to reduce overall VMT.

Maryland has re-entered the discussion with a refiled VMT mitigation bill. This proposed legislation, however, includes a significant change from its earlier version. It raises the cost threshold for projects requiring a mandatory VMT impact assessment from $5 million to $100 million. This means only projects with very high price tags would trigger a review under the bill's provisions.

The elevated $100 million threshold in Maryland’s refiled bill will significantly alter its potential impact. This change means a much smaller number of transportation projects will undergo the required VMT impact assessments, effectively narrowing the scope of the legislation. While VMT mitigation aims to address issues like congestion and emissions, the higher threshold could exempt numerous mid-sized projects from scrutiny, potentially limiting the bill’s overall effectiveness in managing VMT growth. The ongoing debate across states reveals varied policy approaches, from broad environmental reviews to specific project-level mandates. As transportation systems evolve, the implementation and impact of VMT policies will remain a key focus for lawmakers and the public alike.