California’s transportation infrastructure has been steadily declining for years, a victim of neglect from dwindling gas tax revenue.  As a result, local governments have been raising their own taxes to fund needed repair and expansion.  But these efforts can undermine environmental goals by encouraging driving and more sprawl.

As the state’s just-released 2030 draft scoping plan for greenhouse gas reduction makes clear [PDF], reducing vehicles miles traveled (VMT) is essential to achieve sustainable growth and emissions in California:

While the majority of the GHG reductions from the transportation sector in this Discussion Draft will come from technologies and low carbon fuels, a reduction in the growth of VMT is also needed. VMT reductions are necessary to achieve the 2030 target and must be part of any strategy evaluated in this plan. Stronger SB 375 GHG reduction targets will enable the State to make significant progress towards this goal, but alone will not provide all of the VMT growth reductions that will be needed. There is a gap between what SB 375 can provide and what is needed to meet the State’s 2030 and 2050 goals. More needs to be done through continued land use changes, synergies with emerging mobility solutions like ridesourcing, and changes in travel behavior, especially among millennials.

Transportation investments can either encourage or reduce VMTs, if they go to automobile infrastructure instead of walking, biking and transit projects.

Now that Democrats have a super-majority in both houses of the legislature, they should prioritize new transportation spending in VMT-reducing investments.  The best way would be to replace the gas tax with a mileage-based fee, with the revenue going only to maintenance of existing infrastructure and new VMT-reducing projects.  The necessary two-thirds vote for that revenue is now possible, at least in theory.

In the long run, it could be the most important environmental legislation for the state to come out of this session of the legislature.