Before the Colonial Pipeline shutdown, the national average gasoline price had exceeded $3 a gallon for only two weeks since 2014. Yet in California, gas prices in recent years have rarely dropped below $3. They now average $4.18 a gallon—$1.14 more than the national average—and in recent months have increased more than prices nationwide. Why do California drivers pay so much at the pump? Blame a higher-octane blend of taxes and environmental regulations.