Marin's road money formula just changed. Here's what it means for Mill Valley

What's happening: The Transportation Authority of Marin (TAM) adopted its FY2026-27 budget on June 25, putting into effect a formula change that shifts how Measure AA sales tax dollars get split among Marin's cities and towns.

The TAM board approved the underlying amendment on March 26. Mill Valley's council signed off on May 4 - one of several required local votes before the change took effect countywide on July 1.

The amendment cuts local road repair's share of Measure AA funding from 22 percent to 18 percent. The difference funds a new category, Reimagine Roadways, which TAM Planning Director Derek McGill told the Mill Valley council is meant for larger, multi-jurisdiction road projects.

Why it matters: According to Mill Valley's own staff report, the change cuts the city's annual local road funding by about $79,000, from $394,035 to $315,264. Vice Mayor Caroline Joachim raised the number directly when the council reviewed the plan on May 4, telling TAM Executive Director Anne Richman: "the annual local road formula funding to be decreased by $79,000... that was my initial concern, how that is going to impact."

The context: The Mill Valley City Council voted 4-0 to support the amended plan on May 4, with Mayor Max Perrey absent. Councilmember Urban Carmel, the city's TAM board representative, called the change "net positive" for Mill Valley, pointing to the crossing guard program as one example. The same amendment raises crossing guard funding from 7 percent to 7.5 percent of Measure AA revenue.

TAM's presentation to the council said the increase was necessary to prevent guards from being cut, since current revenue only covered a portion of the program's positions countywide without it. Carmel called the program essential to Mill Valley: "That's an important program that we've got in our town. Otherwise, you can't maintain the roughly 100 crossing guards that we've currently got within the county."

TAM will also combine funds it collected under the old formula with funds it projects under the new one, providing Mill Valley roughly $709,000 this fiscal year before the smaller annual amount takes effect going forward.