SB 375 may rattle the balance between local and state control of land use and transportation planning this month, as the San Diego Association of Governments and California Air Resources Board take on the unique challenge of implementing integrated, climate-conscious regional planning.

About a month ago, SANDAG unveiled its “sustainable communities strategy” for the Air Resources Board and others to scrutinize. It is the first of the state’s 18 metropolitan planning organizations to try meeting the state air board’s regional targets for reducing greenhouse gas emissions from traffic. However, reaction to the plan was not all applause.

The Air Resources Board requires SANDAG to cut greenhouse gases by 7 percent by 2020 and 13 percent by 2035. San Diego’s plan says the region will cut 14 percent by 2020, which will slide to 13 percent by 2035, and then fall off significantly by 2050. Environmental groups complain this “backsliding” after 2035 is unacceptable.

The Board’s staff also complained in its report that the Board had set targets for each region with “an expectation that the benefits of an SCS (sustainable communities strategy) would increase with time given the nature of land use patterns and transportation systems.” Staff expressed concern that, in SANDAG’s plan, downward pressure on greenhouse gas levels wouldn’t outlive SANDAG’s statutory duty to apply it.

Critics also complain that SANDAG’s plan favors highways over public transit by programming highway investments in the near-future while putting off transit for decades.

How these particulars are relevant to California’s other regional agencies is still unclear. But what is fundamentally relevant is how the Air Resources Board chooses to follow through on its complaints. Those complaints raise an important question: How much of a role will state regulators play in shaping the policy of regional transportation plans?

Although SB 375 sets new goals for regional plans, it also reserves for local governments the choice of how to reach those goals; the law declares that the state board’s review of the SCS “shall be limited to acceptance or rejection of the metropolitan planning organization’s determination that the strategy would, if implemented, achieve the greenhouse gas emission reduction targets established by the state board” (Government Code section 65080) – a standard that SANDAG’s plan does meet.

But other state departments and agencies already exercise broad authority over other aspects of regional plans, albeit typically as an extension of regulating local general plans. For one, the state’s Housing and Community Development Department regulates how cities and counties zone for affordable housing – a huge dimension of regional plans. The California Resources Agency updates the regulations implementing CEQA, including those applying CEQA to transportation plans’ climate impacts.

And where state requirements don’t apply to regional plans, reams of guidance from such state agencies as the Office of Planning and Research influence virtually every aspect of the local planner’s work. Various funding sources that also determine local and regional planning flow or ebb at state departments’ choosing, such as Department of Conservation grants that support local governments’ agricultural conservation easements.

So the state’s grasp over the particulars of each region’s “sustainable communities strategy” may still be in a gray area. While not directly affecting the strategy per se, various state officials still influence the strategy’s material components – housing, transportation, open space – which, as a key characteristic of SB 375, are extraordinarily integrated in a single plan. As a result, state regulators have a lot of strings to pull that may still affect how SB 375 is realized.

Policymakers have historically questioned whether disconnected city-by-city decision processes can adequately address land use and transportation problems that so often transcend city and country boundaries – traffic, jobs-housing balance, climate change, etc. Then again, proponents of local control worry that vesting too much power in Sacramento adds red tape and diminishes residents’ voices in the public process.

SB 375 brings those questions to the forefront.

Josh Rosa is a Sacramento Housing and Redevelopment Commissioner