If King County wants more dollars for bus service, it should raise sales taxes, not car-tab fees, says Sen. Curtis King, R-Yakima, co-chairman of the Senate Transportation Committee.

King released his Republican version of a 10-year, $8.4 billion state transportation plan on Monday. Like his House counterpart, Rep. Judy Clibborn, D-Mercer Island, he calls for a 10-cent increase in the state gasoline tax, mainly to pay for highway expansions, and smaller shares for ferries and road maintenance.

The main differences involve transit — historically a local obligation with minimal state aid. The question is, what taxing tools should transit providers even be allowed to use? King has previously said he doesn’t think drivers should bear the burden of funding buses.

Instead, his plan would allow the present sales tax for transit, of 0.9 percent, to be raised to 1.2 percent — only if voters approve a ballot measure.

A House Democratic bill, championed by Rep. Jessyn Farrell, D-Lake Forest Park, would have allowed the Metropolitan King County Council or voters to impose a car-tab tax of $150 per $10,000 of vehicle value, with 60 percent for transit and 40 percent for roads.

Metro says it needs $75 million a year to meet rising demand, and to replace a temporary $20 car-tab fee, as well as funds from the Highway 99 tunnel program, both of which expire in 2014. Currently, the sales tax pays for 54 percent or $346 million of Metro’s $640 million annual operating budget, so an additional 0.3 percent translates to $114 million a year.

But sales taxes could meet resistance in liberal King County because they are “regressive,” meaning they affect lower-income people disproportionately. Environmental advocates tend to favor taxing cars, not everyday purchases. Washington state currently has the nation’s most regressive tax structure, according to the Institute for Taxation and Economic Policy.

“The car tab, MVET (motor-vehicle excise tax) puts all of the monkey on the back of the person that wants to drive a car. … I think of transit as being more of a social issue, and a sales tax socializes that cost,” King said.

Under his plan, King County could collect a $20 car-tab fee until 2018 for roads and bridges, and Pierce and Snohomish counties would gain the ability to charge the same fee.

It appears the transportation differences will be ironed out in a second special session, if at all.

“I don’t think anything’s going to happen before then,” King said.

Mike Lindblom: 206-515-5631 or mlindblom@seattletimes.com.

On Twitter @mikelindblom