The downtown Seattle bus tunnel will close in about 18 months to be retrofitted for joint use by buses and Sound Transit's light-rail trains, officials announced yesterday.
The closure, for up to two years, is no surprise, but the timing is. Sound Transit and King County, which owns the tunnel, had originally planned to keep the tube open until 2007.
Sound Transit CEO Joni Earl said shutting down the tunnel earlier — it now will close in September 2005 — could reduce construction costs and perhaps move up the timetable for completion of the 14-mile light-rail line from downtown to Tukwila.
Trains now are scheduled to start running in 2009.
The tunnel's closure will alter thousands of commutes and increase downtown congestion. King County Metro says 23,000 commuters use the tunnel to get to work every weekday.
When it closes, 140 buses that now run through the tunnel each weekday between 4:30 and 5:30 p.m. — the busiest hour — will be rerouted, mostly to Third Avenue. That will increase the total number of north-south buses on downtown streets by more than 20 percent.
Sound Transit, King County and the city of Seattle plan to spend $16 million, mostly on surface improvements, to keep traffic moving. Third Avenue, for example, will be closed to almost all traffic except buses and emergency vehicles during the morning and afternoon peaks. Despite those efforts, Sound Transit and Metro studies indicate the extra bus traffic will increase average delays at some downtown intersections from one to 20 seconds. Most buses that are rerouted from the tunnel to the surface will take six to seven minutes longer to get through downtown.
"This will increase the travel times — no doubt about it," said Rick Walsh, Metro's general manager.
The planned closure comes over the objections of the Downtown Seattle Association, which has long advocated keeping the tunnel open until Sound Transit identifies a route and finds the money to extend the light-rail line to Northgate.
But association president Kate Joncas, who was among business leaders briefed on Sound Transit's plans Wednesday, acknowledged there's probably little the organization can do to keep the tunnel open: "The best we can do is make our case heard."
Sound Transit plans to pick a preferred route to the University District and Northgate later this year. Funding remains uncertain.
Earl said yesterday that Sound Transit originally scheduled the tunnel closure for 2007 to have more time to address downtown business concerns. But she said that's outweighed now by the opportunity to possibly save time and money.
Finishing the tunnel work in 2007 will give the agency more time to test trains there and avoid possible delays, Earl said. And signing a contract for the tunnel retrofit sooner could take advantage of the competitive environment among construction firms that has brought lower-than-expected bids for other light-rail contracts, she added.
That makes sense, said Greater Seattle Chamber of Commerce president Steve Leahy, who also was briefed on Sound Transit's plans.
"If you can save money along the way, that means more money to be sure to get to the U District and beyond," he said. "That's a good thing."
But he said the chamber shares many of the Downtown Seattle Association's concerns about more buses on the streets: "We're hoping that Sound Transit's contractors deliver so the closure would be shorter."
During the retrofit Sound Transit will install new rails, overhead electrical wires and sprinklers, put in a new signal system to keep buses and trains separated, and improve the emergency ventilation system.
It also will lower the roadbed in the stations by six inches so passengers can walk or wheel themselves directly from the platform onto rail cars and onto new, low-floor buses without climbing stairs or using wheelchair lifts.
The price tag was estimated at $62 million to $68 million in 2002.
When the tunnel re-opens in 2007, buses would have it to themselves for two years. When light-rail service begins, Sound Transit and Metro estimate 120 buses — fewer than today — and 20 trains would serve the tunnel during the afternoon rush hour. It would be the nation's first tunnel shared by rail and buses.
The anti-rail Coalition for Effective Transportation Alternatives has long argued that more buses in the tunnel would serve more people more efficiently than trains. Leaders of that organization could not be reached for comment yesterday.
Earl, Walsh and Grace Crunican, director of the city's transportation department, emphasized the retrofit won't be nearly as disruptive to business as construction of the tunnel in the late 1980s was. That job required a big trench down the middle of Third Avenue.
But Sound Transit does plan to dig a short stub tunnel under Pine Street between Seventh and Terry avenues so trains can turn around after they reach the line's northern terminus at Westlake Center. Construction will start this fall and take up to two-and-a-half years.
During that time, Pine Street between Seventh and Boren avenues, now two lanes westbound and one eastbound, will be restricted to one westbound lane.
Seattle Times staff reporter Susan Gilmore contributed to this report.
Eric Pryne: 206-464-2231 or firstname.lastname@example.org