Crisis plan in place if viaduct is closed

A key part of the updated plan, released yesterday, is early communication. Drivers will be advised of closures and alternative routes, and will be urged to use alternative transportation for long-term closures.

Agencies including police, fire, and utilities will be notified in a specific order. Officials stressed that the plan, which outlines steps to be taken under four different scenarios, is still in development and must be flexible to react to a range of situations.

The new plan was developed after the City Council found serious shortcomings in an earlier version. "This new plan puts us on a more solid footing," said Council member Richard Conlin, chairman of the council's Transportation Committee. "Earlier shortcomings have been replaced by clear lines of communication with responsible parties identified in advance and personnel needs defined."

Public meetings will be held to gather comment.

The emergency plan will also be used during the possible replacement or removal of the viaduct, which could start in 2007 as utilities are moved.

About 100,000 cars, trucks and buses use the Alaskan Way corridor each day. Built in the 1950s, the viaduct is vulnerable to earthquakes, but could also be closed for long periods by hazardous spills, fires or accidents. The corridor connects major parts of the city and downtown.

Replacing or repairing the aging structure is one of the region's primary transportation goals, though officials must still decide exactly what to do and where to get the billions of dollars a replacement could cost.

More details about how traffic will be managed during the years-long construction period will be further released next year.

In the meantime, plans assume that the monorail is operating during the construction period, transportation officials said yesterday.

The updated plan details steps that will be taken for emergencies ranging from simple collisions to a major earthquake that sends the viaduct crumbling onto Alaskan Way and blocking the corridor.

Officials said that while the viaduct could shift dangerously in an earthquake, it is unlikely that it will collapse completely.

In the case of an emergency, portable signs would immediately be moved into place to alert drivers. Radio stations would be alerted and details posted on state and city Web sites.

In some cases state Route 99 would be closed quickly and traffic would be diverted through alternative routes and to Interstate 5.

James Street in downtown Seattle would be closed to all traffic except emergency vehicles.

Buses would be used to transport trolley passengers if the George Benson Waterfront Streetcar were put out of service. Other travelers would be encouraged to use buses, bicycles or a car pool.