Viaduct Closes For İnstallation Of Quake Gates

Earthquake upgrades and a safety inspection are keeping Seattle's Alaskan Way Viaduct closed all day Saturday and Sunday - and left drivers hunting for alternate routes.

The upgrades included new crossing arms and warning bells designed to save lives if an earthquake strikes, helping to keep drivers from putting themselves in more danger on the viaduct.

"It keeps a whole bunch of people from going into a potentially dangerous situation," says Matt Preedy of the state Department of Transportation.

Animation released two years ago showed the hypothetical destruction a major quake could cause to the aging viaduct.

The automated closure system involves nine gates placed at viaduct access points - extending from the Battery Street Tunnel to South Spokane Street.

If an earthquake rumbles, all of the gates would lower simultaneously, warning lights would flash and bells ring - telling drivers to steer clear.

The safety systems are activated by a series of seven seismic sensors. Three of the detectors have to register a 5.0-magnitude quake or greater to trigger the system.

Transportation workers say if drivers somehow fail to notice the lights and bells and hit the crossing arms, they likely won't get hurt.