OLYMPIA, Wash. — The Washington State Supreme Court has upheld vehicle registration tax increases in the Puget Sound area, a decision that preserves billions of dollars in voter-approved money earmarked for light rail and other projects.

Seven Puget Sound residents filed the lawsuit to overturn a rate increase by Sound Transit.

Voters in 2016 approved the rate hike to fund the Sound Transit 3 expansion project. The lawsuit sought a refund of millions of dollars in car registration fees collected through the increase to help pay for the $54 billion expansion. 

The plaintiffs argued the 2016 voter-approved measure was not legal because state lawmakers were not clear how the car tab fees were going to be calculated.

In a 7 to 2 decision Thursday, the high court justices found that the motor vehicle excise tax was constitutional.

Senator Steve O’Ban (R-Pierce County), who has been sponsoring legislation to restructure how car tab fees are calculated in Washington, called Thursday’s ruling by the Washington State Supreme Court “disappointing.”

Also see | Judge rejects most of legal challenge to Washington's $30 car-tab measure

This is a separate case from Initiative 976, the voter-approved measure that would cap car-tabs renewals at $30.

Sen. O’Ban said Thursday’s ruling underscored the need to enact I-976.

“This decision also underscores the importance of the Legislature, in session right now, to pass my bill to enact $30 car tabs and not leave the matter to the courts,” O’Ban said in a statement. “The Legislature has the power to give taxpayers the relief they demanded by passing I-976. It can pass my bills that enact I-976 and allow Pierce County to exit from the ST3 project. That would go a long way to earning back that public trust.”

RELATED: Republican lawmakers introduce bill to cap car tab fees at $30 in Washington

Sen. Marko Liias, D-Mukilteo, has sponsored a bill to give car owners car-tab relief. He estimates his bill, Senate Bill 6606, could save car owners $30-50 a year while also allowing multiple payments over the year.

Liias considers it a compromise bill.

"I'm trying to knit a path that's sort of between Sound Transit and Tim Eyman," said Liias. "Sound Transit wants to do nothing. Tim Eyman wants to destroy light rail. We're trying to find that middle path."

Since Liias' measure would repeal I-976 it would require a two-thirds majority to pass out of the House and Senate.

"We would like to find bipartisan agreement that solves this problem," said Liias.