Supporters and opponents alike are touting SB 375 as the most significant land use reform bill in recent California history. When he signed it in September, Gov. Schwarzenegger called it the biggest bill since passage of the California Environmental Quality Act 38 years ago. Meanwhile, the hilariously over-the-top Orange County Register has called the bill "one of the most authoritarian, far-reaching and elitist bills that has ever made it to the governor's desk."

In fact, it is neither. Senate Bill 375 is not a revolution. Rather, it is a step – admittedly a very big step – in California's gradual transformation from suburban planning to urban and metropolitan planning. This transformation does not begin with SB 375 – nor will it end with SB 375.

At bottom, this highly publicized bill – pushed through the Legislature for two years by the Senate's now-leader, Darrell Steinberg (D-Sacramento) – is an air-pollution bill. The goal is to promote growth patterns that will help to reduce greenhouse gas emissions (mostly carbon dioxide) by reducing driving.

It's also a regionally based bill, not one that places all the power in Sacramento. The California Air Resources Board will set targets for greenhouse gas reduction via land use in each region. Then each region's Metropolitan Planning Organization (MPO) – such as the San Diego and Sacramento associations of governments – must create a "sustainable communities strategy" as part of the Regional Transportation Plan that will meet the target.

The bill is incentive-based, not regulatory. Transportation projects that go through the MPOs must conform to the sustainable communities strategy – but those judgments are made by the MPOs themselves. There are CEQA exemptions and breaks for projects that conform to the sustainable communities strategy – but nothing mandatory. And, at the behest of local government lobbyists, the law specifically states that local land use authority is not usurped or overridden by SB 375.

All this is not really revolutionary land use reform – especially compared with the pathbreaking growth management bills passed in Oregon during the 1970s, Florida during the 1980s, and Washington during the 1990s.

In Oregon, the most top-down system in the country, the state required the creation of urban growth boundaries around each metropolitan area and established a state department to oversee implementation of the law. In Washington, there was more power-sharing with the locals and the system is more incentive-based, but the locals must meet state growth goals and local decisions may be appealed to regional land use boards. In Florida, all local plans must be approved by the state government, and all plans within the same county must be submitted for state review at the same time.

All three of these laws had two things that California still does not have: a strong and direct role for the state government and an overt focus on the actual use of land. Senate Bill 375 is clearly intended to alter land use patterns, but most of the language that overtly tied the bill to things like urban growth boundaries and protection of resource lands got removed or heavily watered down.

In other words, SB 375 is by no means a comprehensive growth management or land use reform law. It's a law designed to alter land use patterns as a means of achieving a small part of a much bigger goal – reducing greenhouse gas emissions.

As such, however, it is a pretty big step in the very gradual shift in California planning policy from a suburban orientation to an urban orientation. This shift is reflective of changes in the state as a whole.

When I first started writing Guide to California Planning in 1989, it quickly became clear to me that California had a land use system that was focused around an organizing concept that even then seemed a bit outdated – "the suburban growth model." The assumption embedded in both general plan law and the California Environmental Quality Act – both of which have not been comprehensively reformed since the early 1970s – is that the context of planning in California is the building out of individual suburban communities. This is part of the reason the general plan law does not require city and counties to acknowledge the plans being created by their neighbors. And it is the biggest reason why CEQA works so much better when applied to an individual greenfield development project than to a small infill project.

By the time Paul Shigley and I finished the Third Edition of the Guide in 2005, the disconnect between the suburban growth model assumed in the laws and the built-out communities that represented California's reality was more obvious than ever. And for almost 20 years – dating back to the real estate boom of the late '80s – planners and environmentalists had been clamoring for comprehensive reform that would bring California into the infill age.

In the meantime, however, California had taken a number of steps – some strong, some weak – to change the old system. For the most part, these steps did not take on general plans and CEQA directly. But the reforms did gradually change both the reality of the system and its underlying assumptions. For example:

• The MPOs now have far more power than ever before to make transportation spending decisions in their regions, while the state has less. As a result, in both the Bay Area and Los Angeles, most transportation capital spending goes to transit, not highways.

• Partly encouraged by a series of state grants, these same regional planning agencies have already devised regional strategies – often called "blueprints" – designed to accomplish more or less the same goal as the "sustainable communities strategy" in SB 375. Implementation is spotty, but everybody has gotten used to the idea of regional agencies doing this kind of planning during the last few years.

• The state has become more aggressive in doling out money to support more urban models of development. Only a few months ago, the Department of Housing & Community Development gave away a half-billion dollars in Proposition 1C money for transit-oriented and infill projects (see CP&DR Insight, August 2008). This is a long way from Maryland's practice of directing most state money to support a particular development pattern, but in a real estate downturn, California's grants will have a significant impact.

• The state has taken sweeping policy steps to embed a more urban development model in the state's own practices – if any governor cared to make use of those policies. Most important is AB 857, the 2002 law that requires that all state actions support infill development, protection of open land, and compact greenfield development. The law has never really been implemented, but it does at least theoretically provide a strong policy foundation for a more urban development pattern.

Senate Bill 375 should not be viewed in isolation. It has to be seen in the context of all these other steps. California has not yet completed the revolution in land use policy that SB 375 seems to promise, and the suburban growth model will clearly die hard. But all these steps put together would seem to suggest that California's land use policy landscape really is headed down a more urban path.