Californians who minimize their driving could shell out less for insurance under a pay-as-you-go plan proposed Wednesday by Insurance Commissioner Steve Poizner. Under the voluntary plan, annual insurance rates would be based on miles driven, incentivizing Golden Staters to stay out of their cars. “As a strong advocate of healthy market competition and a healthy environment, I am especially pleased to encourage this kind of innovation and additional options for consumers,” says Poizner. A recent study found that two-thirds of California households could save an average $276 per vehicle by opting for the plan; participation by 30 percent of Californians would save 5.5 billion gallons of gas and cut greenhouse gases by 55 million tons over the next 11 years, according to the Environmental Defense Fund. Thirty-four other states have similar pay-as-you-go plans; Poizner hopes to have California’s in place by no later than fall 2009.