OLYMPIA, Wash. Truckers and motorcoach operators across the state of Washington are poised for the next legal step in a potentially far reaching case where the Washington supreme court applied a state overtime provision to interstate truck drivers who work more than 40 hours in a week, regardless of whether a portion of those hours took place outside the state.

In a 5-4 opinion, the court ruled that all Washington workers are entitled to the states mandatory overtime pay even interstate truckers who spend many of their working hours out of state.

The court rejected nearly 20 years of rules and rulings by the Washington Department of Labor and Industries which expressly held that interstate truck and bus drivers are eligible for overtime only if they work more than 40 hours in a week within the state.

"Since 1989, the law has been clear for when overtime was paid for Washington interstate carriers," said one attorney involved in the case that was decided last month.

The court also rejected claims that interpreting overtime eligibility -- that is based on hours wherever worked -- would violate the U.S. Constitution Commerce Clause as unduly burdening interstate commerce.

In the case that prompted the ruling, the court ordered Food Express, an Arcadia, Calif.-based trucking company, to pay Larie E. Bostain $9,000 in overtime pay, plus court costs.

The decision overturned a state appeals court ruling against Bostain, who worked at Food Express operation in Vancouver, Wash., for a decade before the company fired him five years ago. The lower court ruled that all hours had to be accumulated in-state for Washingtons Minimum Wage Act to apply.

The higher court disagreed.

"The statute makes no distinction between the hours spent driving in state and those spent driving outside Washington," Justice Barbara Madsen wrote in her majority opinion.

Justice James M. Johnson wrote in his dissent that the ruling not only contradicts Washington law and regulation but "runs afoul of the Commerce Clause" of the U.S. Constitution, which empowers Congress to regulate interstate commerce. Furthermore, the majority opinion subjects the trucking industry to the "vagaries" of legal analysis "regarding a key business decision," Johnson wrote.

The majority, however, was unconvinced that a Commerce Clause violation occurs when an employer is merely subject to additional expense, Madsen wrote.

The dissenting opinion also honored the administrative interpretations of the statute and the state legislatures acquiescence in those interpretations.

The potential impact of the ruling extends far beyond Food Express.

Dale "Hal" Schofield, an attorney who represented Food Express in the case, said the decision reverses the "bright line" of distinction between in-state and out-of-state work, enabling "hundreds of thousands" of truckers to file for back overtime pay during a three-year statute of limitations.

In other words, think class-action lawsuit against Washington state truckers and motorcoach operators by drivers seeking overtime pay.

Philip Talmadge, a former state Supreme Court justice who represented the Washington Trucking Associations in a friend-of-the-court filing, said the opinion "wreaks havoc for trucking carriers in interstate commerce."

An appeal to the U.S. Supreme Court is considered likely. Schofield said as much, as did the American and Washington Trucking Associations.

Talmadge said the decision would force interstate carriers to ask: "Which law do I apply?" Washington statute requires overtime pay for hours completed in-state; California requires overtime pay whenever eight hours are exceeded in one day, and Oregon requires no overtime pay at all for interstate drivers.

United Motorcoach Association board member Gladys Gillis of Starline Transportation, a Seattle-based motorcoach company, said that until the issue is decided, coach operators need to make sure their wage practices and policies take the decision into account.

She said her company is working closely with the state Department of Labor and Industries to adopt policies that are prudent.

She also wondered aloud whether the Department of Labor and Industries isnt at least partially culpable for any overtime pay that operators might have to pay based on its past recommendations and rulings if the court decision stands.