Highway projects' tab goes up 31%

Highway projects in the Puget Sound region will cost at least 31 percent more than earlier estimates.

Even if voters pass a huge ballot measure in November, new state figures show that the plan will deliver fewer road lanes to ease congestion in King, Snohomish and Pierce counties.

Suburbs south of Seattle could face the most dramatic cuts.

Thirteen regional projects now require $16 billion to build as originally hoped, up from $12.2 billion as of last January, a Seattle Times review found. So far, only $10.2 billion is earmarked from the ballot proposal plus existing gas taxes — leaving a $6 billion gap.

The total will be higher if Seattle's Alaskan Way Viaduct is replaced with a tunnel instead of a less-expensive elevated structure.

There are several reasons for the cost increases.

Cement prices spiked. Steel prices rose, largely because of competition from new skyscrapers and roads in China. A flurry of megaprojects, and the post-hurricane reconstruction of New Orleans, triggered a labor shortage that may continue for years.

The Washington State Department of Transportation recently substituted a more-realistic inflation rate of about 3.5 percent for its previous figure of about 2.4 percent, which outside experts had challenged as too low.

The new figures account for more environmental work, notably at Highway 2 in Everett, where road trestles cross the wetlands of Ebey Island, and at the new "Cross-Base Highway" in Pierce County.

Politicians have expected this news since September, when the state increased its figures for Alaskan Way and the Highway 520 floating bridge.

But the new reports explain, for the first time, the state's thinking about how to trim elements of other projects, such as:

• Highway 167, Green River Valley. Cost increases make it impossible to add even one general-purpose lane in each direction from Auburn to Renton, as once envisioned.

Instead, the DOT suggests shifting $120 million — out of $420 million set aside in the ballot measure for this project — to high-occupancy vehicle ramps where 167 meets Interstate 405, near the Renton S-curves. The remaining $300 million would widen a chokepoint near Highway 516 in Kent, and create a northbound HOV lane from the Pierce County line to south Auburn.

Instead of mainly benefiting single drivers, the money would promote car pools.

A related project, adding HOV lanes through Auburn, will be done with existing gas taxes.

• Highway 509, SeaTac. A six-lane freeway extension from west of Seattle-Tacoma International Airport to Interstate 5 would be slimmed down to four general-use lanes. A pair of HOV lanes, and three new lanes on I-5 to Federal Way, would be deferred.

• Interstate 405, Bellevue to Renton. The state would still be able to add a pair of general lanes in each direction, from the Maple Valley Highway to Interstate 90. But a flyover ramp from westbound 520 to southbound I-405, and other interchange improvements, would be deferred.

• Highway 9, Lake Stevens to Clearview. The plan in sprawling central Snohomish County, to expand a two-lane highway to four or five lanes, is $59 million short. That would mean spreading construction over several years, instead of widening the whole corridor at once.

Prices for many projects will likely rise further, because these figures represent only a midrange estimate. And the figures assume construction would start within three years.

Unlike with the viaduct or a 520 bridge, the state could accomplish quite a bit of work on its surface highways in the suburbs — one mile at a time — using whatever dollars are available.

"This is still a workable, doable package," said Pierce County Councilman Shawn Bunney, who chairs a planning committee of council members from three counties. The group, under the name Regional Transportation Investment District, is scheduled in April to issue a final project list for the fall ballot.

Along with 13 big projects, the measure was to include some $700 million for smaller projects. Those are now "on the table," Bunney said. Some might be dropped so more lanes can be built on the 13 big projects.

The highway plan depends on voters passing car-tab-tax and sales-tax increases totaling $100 to $120 a year for an average household.

At the same time, voters will be asked for a similarly sized sales-tax increase to extend Sound Transit rail. The proposed transit tax, combined with a continuation of Sound Transit's existing taxes, would bring in $19 billion for future construction and operations over two decades.

Both the transit and highway funding must win at the polls, or both fail.

Rob Johnson, regional policy director for the pro-transit Transportation Choices Coalition, said the new figures make the political situation more complex. State and local elected officials must unite on a final plan in the next few weeks, he said, if they have any hope of running an effective campaign.

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