This increase took place despite Washington lawmakers' ongoing efforts to keep uninsured drivers off the roads. The state has had mandatory-insurance law since 1963, requiring that all drivers carry a proof-of-insurance card.

"Uninsured drivers are a reality, and they cause a lot of hassle, including forcing higher premiums," said Jon Osterberg, PEMCO spokesperson. "The good news is, [insured drivers] can cut down on the cost and hassle tremendously with just a little knowledge, a notepad and a list of information to collect."

PEMCO said its statistics show that uninsured drivers exist in significant numbers on Washington's roadways.

PEMCO noted that some uninsured drivers avoid getting insurance because of the perceived high cost or a poor driving record. But the carrier advised that drivers with poor driving records should first contact their previous insurance company to ask for a new quote before making any assumptions.

"Companies typically review only the previous three years of driving history, and the rates may be lower than expected. Drivers may also qualify for discounts they weren't eligible for earlier," the company advised.