Yakima County, No. 7 in the state for population, ranks third for the number of drunken-driving deaths.

Hundreds of Yakima County residents are charged each year with driving under the influence of intoxicating drugs or alcohol. Perhaps as many as three-quarters of them hit the road soon after their arrest without worrying whether they can legally drive, sometimes being stopped again for more traffic offenses or crashing their vehicles.

Statewide, drivers without valid licenses are involved in nearly 20 percent of all deadly crashes, officials say.

Advocates of a new law that goes into effect Jan. 1 hope it will help reduce the numbers of deaths here and across Washington.

The measure creates a special driver's license category allowing DUI defendants to drive legally while awaiting the disposition of their case. They must agree to use a device that measures their body's alcohol content before the car will start.

Otherwise, their license would be suspended. Under current law, they could receive an interim license, but nothing would stop them from driving drunk.

"You're stupid not to get this driver's license," said Rep. Roger Goodman, the Kirkland Democrat who sponsored the bill.

Goodman said statistics from New Mexico, the model for the Washington law, suggest that the change could save 100 lives statewide per year, based on 2006 traffic deaths here.

Twenty-six occupants or pedestrians died in alcohol-related crashes in Yakima County that year. Slightly more than 600 died across the state.

Yakima County ranks third in the state -- behind much more populous King and Pierce counties -- for the number of alcohol-related crashes in the state.

"To me, that indicates a problem. I think it's significant," said impaired-driving program manager Shelly Baldwin of the Traffic Safety Commission.

State statistics suggest that Yakima County residents are twice as likely as the average state resident to die in crashes caused by impaired drivers.

Between 1997 and 2006, the statewide rate of fatalities involving impaired drivers was 0.49 per 100 million vehicle miles driven.

Yakima County's rate was 0.90, according to figures from the traffic safety commission.

Already, 2,650 post-conviction defendants in the county require an interlock, according to the state Department of Licensing. Put together, they would equal the population of Zillah.

The Department of Licensing is still developing the interlock program, including pilot projects in Eastern and Western Washington to gauge success. The Washington State Patrol and the Washington State Traffic Safety Commission will be involved in that process as well.

First-time offenders must use the device for a year after being convicted, with increased terms for subsequent convictions. That stays the same under the new law.

But Goodman also wanted to reduce the time a DUI defendant could spend on the road before asking the Department of Licensing for an administrative hearing, where a department official considers letting the person drive.

The new law pushes that period down to 20 days from 30.

Lucy Guyaz, co-owner of Union Gap-based Yakima Interlock, said she expects business to pick up once the new law goes into effect.

Guyaz and her partner, who has operated a similar business in the Tri-Cities for five years, opened the new branch in February.

They based their decision to expand more on Yakima County's number of DUI defendants than on the new law, Guyaz said.

"It's scary, when you think about it," Guyaz said, noting that drivers with an interlock qualify for "instant jail time" if they are caught driving drunk.

Although it will still be possible for drivers to illegally circumvent the interlock, New Mexico's experience suggests that the program increases compliance and reduces deaths.

According to New Mexico statistics, the recidivism rate there was close to 4 percent over the three-year study period. The study showed that recidivism prior to the interlock law ran close to 14 percent.

An interlock user from Pasco -- a customer of Yakima Interlock's sister company in the Tri-Cities -- said the device has helped him.

The man, whom company officials did not identify because of confidentiality concerns, was arrested after one of his regular stops at a bar on the way home from work.

"I think it's a safety thing for me," the man said. "It keeps me from stopping at a bar and having a beer. It does work."

* Mark Morey can be reached at 577-7671 or mmorey@yakimaherald.com.