Industry disputes findings.
Insurers said increased competition, not Proposition 103, was responsible for declines in auto rates. California-based consumer groups, meanwhile, said the heart of Proposition 103 has never been implemented. Voters approved Proposition 103 after auto insurance premiums spiked during the 1980s to some of the highest rates in the nation, with urban drivers typically paying far more than their rural and suburban counterparts. But insurers are still allowed to set premiums largely based on ZIP Codes. It's quite an achievement to be where we are in terms of having lower rates.