It’s a long overdue step.  The U.S. federal government disproportionately funds automobile infrastructure without requiring any metrics related to key environmental impacts, namely carbon emissions.

But new rules could change that.  Per Streetsblog USA, the U.S. Department of Transportation unveiled a controversial proposal last week requiring state DOTs to track their performance:

Reformers hoped the rules would get states to reconsider highway expansion as a method of dealing with congestion and emissions, since widening roads induces more traffic and pollution. By introducing better metrics and reporting requirements, the thinking goes, U.S. DOT could compel states to document the failure of highway expansion, which would lead to pressure for a new approach.

Streetsblog is already critical of the rules, calling them “hugely disappointing.” They’d like them to go farther. Of course, road builders argue that the proposed rules are outside of the scope of statutory authority and are therefore invalid.

At this point, I think even weak rules are a major step forward, to establish the principle that these highway projects need some objective justification based on common-sense measures.  In addition to carbon emissions, they should account for vehicle miles traveled, including induced travel, sprawl impacts (including induced sprawl), public health effects, and basic cost effectiveness.

In theory, the National Environmental Policy Act already requires this disclosures and analysis.  But having these impacts tracked as conditions for funding under department guidelines really changes the ballgame.  And weak initial rules can be tightened over time.

All in all, it’s a step in the right direction and hopefully the beginning of a sprint to clamp down on bad highway projects funded by our tax dollars.