Highway cost estimates startle

The good news first: Despite a series of eyebrow-raising new cost estimates to fix Puget Sound’s worst traffic nightmares, the price for the long-awaited North Spokane Corridor turned out about the same as expected.

The bad news: It’s still a lot of money, and much of the work depends on an iffy statewide ballot measure that voters will decide on this fall.

The corridor, a multilane highway link between U.S. 395 and Interstate 90, is pegged at $1.3 billion to $1.4 billion in 2011 dollars under new cost estimates from the state Department of Transportation.

It was originally estimated at $875 million in 1994, a difference that the department says is primarily due to inflation and some minor design changes. An independent check with several Internet-based inflation calculators showed that the $875 million is worth about $1.05 billion today.

“When they put the North Spokane Corridor under this microscope, we did very well,” said Al Gilson, a department spokesman in Spokane.

In central Puget Sound, however, the new estimates were startling. Replacing Seattle’s Alaskan Way Viaduct could cost $3.2 billion to $11.6 billion, depending on what combination of rebuilding and pricey tunneling is chosen. That top price would be the equivalent of nearly $2,000 for every person in the state.

Another project, adding four lanes to a roughly 25-mile stretch of crowded Interstate 405 east of Seattle, would cost $9 billion to $11 billion.

Officials in Puget Sound are trying to put together a plan to raise billions of dollars in local taxes there to get the projects started. The new cost estimates, which the Seattle Times labeled a “whopper” and “eye-popping,” are likely to raise the stakes.

Spokane’s major project on the list, the corridor, has simmered largely on the back burner since it was first proposed in the mid-1940s. The problem is that Eastern Washington’s main north-south highway, U.S. 395, linking Mexico and Canada, runs smack-dab through a maze of stoplights and cross-streets in north Spokane.

The $1.4 billion fix would build a new freeway, up to eight lanes wide, from Wandermere through north Spokane, over the Spokane River, onto a new three-mile stretch of I-90, and back onto U.S. 395. The change would save about 1.7 million gallons of gas each year, the department estimates, scrub more than 2 million pounds of carbon dioxide from the region’s air, and save 2 million hours a year of drivers’ time.

The state has spent about $51 million on the project since 1999, most of it buying and preparing land in the northern stretch between Hawthorne Road and Farwell Road. At best, the one-mile stretch there is expected to be drivable in 2008.

“We want to secure as much of that right of way as possible before it all becomes homes and businesses,” said Gilson.

The later phase from the Spokane River south to I-90 will be much more expensive, since it’s heavily built up already.

“Up north, we can buy land by the acre,” said Gilson. “Down south, we buy it by the square foot.”

Some of the work involves major changes, like lowering Farwell Road 13 feet and putting the corridor on bridges going overhead, or lowering and straightening parts of I-90.

A huge part of the project - $206 million - rides on whether voters approve a 9-cent gasoline tax and other new fees this fall. The measure, Referendum 51, would raise $7.7 billion for transportation projects statewide. Some Eastern Washington lawmakers worry about a Puget Sound proposal competing on the same ballot for voter dollars; others doubt that the region will be able to agree on a proposal in time.

Whatever happens, it won’t be quick. The new cost estimates project completion in 2018, and it could take even longer. Even if $1.4 billion were in-hand and all the construction equipment ready to roll, construction would still take a decade, Gilson said.