"I am not going to mince words," King County Councilwoman Julia Patterson told participants at an open house on regional transportation at Highline Community College last week.

"This would be the largest investment of tax revenue in the past 50 years."

Patterson was referring to a roads and transit-funding measure slated for the Nov. 6 election ballot.

The measure, as currently proposed by the Regional Transportation Investment District and Sound Transit boards, would raise $9.8 billion for transit and $6.7 billion for roads in King, Pierce and Snohomish counties.

Patterson is vice chairwoman of the Regional Transportation Investment District planning board and a Sound Transit board member,

Two sources of tax revenue would fund the transportation package. A sales tax of 0.6 of 1 percent would be imposed, and vehicles would be assessed a fee of $80 for every $10,000 of value.

Proponents estimate the average household would pay an additional sales tax of $150 per year. The owner of an average vehicle valued at $8,500 would pay $68 per year.

The two taxes added together mean an average household would pay about $218 a year for the transit and road improvements.

Despite the fact that 9-cents-a-gallon increase in the state gasoline tax was approved by the 2005 Legislature, the new funding proposal is also needed, according to Patterson.

"The longer we wait, the more expensive it becomes," Patterson declared.

With the local economy recovering after the September 11, 2001, terrorist attacks, area rush hour commutes are becoming worse, she observed.

Projections are that in the next 20 to 25 years, 1.2 million people-equal to the current population of metropolitan Portland-will be added to the Puget Sound area.

The Interstate 405/ State Route 167 interchange just east of Tukwila is the worst traffic chokepoint in the state.

Traffic is badly congested from Tukwila to Bellevue for five hours each weekday morning with average vehicle speeds of 23 miles per hour, Patterson added.

Besides the 405/167 interchange, several Highline transportation improvements are part of the proposed package: extension of Sound Transit light rail south of Sea-Tac, rapid bus transit serving Burien and the state Route 509 extension,

Sound Transit would extend its light-rail line 15.6 miles south of Sea-Tac International Airport with new stations at South 200th Street in SeaTac and the Kent-Des Moines Road near Pacific Highway South in Des Moines.

The line would go farther south with stops in Federal Way and Fife before hooking up with the existing downtown Tacoma light rail train at the Tacoma Dome.

Officials studied bringing light-rail west to Burien, but opted instead to stretch out the line as far as possible north-south and across the I-90 floating bridge to the Eastside, according to Patterson.

Sound Transit senior planner Eric Chipps noted long-range plans are to provide rapid bus transit to Burien.

Sound Transit plans to contribute $12.5 million for 500 stalls in the parking garage at the Burien Transit Center when it is remodeled, Chipps said.

The proposal also calls for a new permanent Sounder commuter train station in Tukwila with a bus loading area and a parking lot with up to 400 stalls. It would replace the temporary station built several years ago.

Construction of the long-delayed SR 509 Extension would be funded as part of the regional transportation package.

SR 509 then would extend south of South 188th Street and connect to I-5. A south access road from Sea-Tac International Airport would hook up with the extension.

Although SR 509 is not overly congested now, the extension would be the "missing link that the freight community desperately needs," Patterson noted.

The extension would provide a primary link between Port of Seattle maritime operations and manufacturing and distribution centers in the Kent/Auburn valley.

Truck traffic would also be shifted off I-5 on the Southcenter hill, Patterson added.

But, she cautioned, the draft proposal is "not a done deal yet."

March 30 is the deadline for public comment with the final plan scheduled to be approved by the Sound Transit and regional transportation district boards in late spring.

Then the King, Pierce and Snohomish county councils must each adopt the plan and a ballot title before elections officials in the three counties place it on the fall ballot.

Responding to an audience question, Patterson said if the ballot measure fails, tolls might be the only other way to fund needed roads.

"This (the ballot measure) is it," she concluded." There is nothing else out there. This is the big opportunity."