Adopting a policy objective to reduce automobile use would be poor public policy, reflecting little more than a knee-jerk political reaction to a long-term environmental problem.
True enough, the passenger automobile is an important source of carbon emissions, but it's not the most important contributor. Industry takes that spot. More importantly, cars emit carbon because of the fuel they use, and that fuel source will likely change dramatically over the next several decades even without interventions from government.
Electric hybrid technologies already have the capability of cutting carbon emissions in half within certain classes of vehicles (e.g., four-door sedans), and more than 65 hybrid models will be available on the American auto market by 2010. Plug-in electric technology is close to becoming commercially viable at today's energy prices, and an electric power system that relies increasingly on nuclear energy, wind, and hydroelectricity means we can reduce carbon emissions without sacrificing the mobility provided by the automobile.
More fundamentally, public policy focused on significantly reducing automobile use in favor of other travel modes - whether it is mass transit, bicycling, or walking - betrays a stunning naiveté about travel or a brazen disregard for the needs of everyday Californians.
Perhaps both. The automobile is popular because it provides maximum flexibility in a society that values mobility.
It allows us to cover more ground more efficiently than any other alternative unless one lives in a niche housing market such as a high-density downtown or within a third of a mile of a transit stop (with meaningful connections).
Most Californians have chosen to live elsewhere, and automobiles represent their travel mode of choice. These choices need to be respected by policymakers, not ignored.