Jessica Mathews' proposal to reduce car usage through payment of part of insurance premiums at the gas pump is not the answer to our traffic and environmental problems {op-ed, Nov. 29}.

Insurance premiums are based on risk. The number of miles a person drives is just one factor that determines insurance costs. If you paid your premium when you fill your tank, you'd find yourself paying for risks others take. You'd pay the same for your gas-pump insurance, for example, as a drunken driver who kills and maims our loved ones. Small, fuel-efficient cars are often the most dangerous in a collision, but their owners would end up paying less for insurance. So while the proposal is simple, workable it is not.

No single answer will keep us from choking on traffic and pollution, though one possible help would be a practical electric car. President Bush should challenge us to go to the labs and garages and factories and build such a a car and the infrastructure required to support it by the year 2010. And we could do this without fouling our air or increasing our dependence on foreign oil. EDWARD H. UTLEY President GEICO Corp. Washington