Hwy. 99 Tunnel Would Be Prepared For Potential Disasters

The proposed Highway 99 tunnel is supposed to replace a threat to public safety — that the old Alaskan Way Viaduct might topple in an earthquake.

But the notion of going underground raises its own set of fears among the public.

A quake might crack the tube, some argue. Commuters could drown in a tsunami. A crash might trap cars and block ambulances. Toxic fumes might outrun evacuees.

While some doomsday comments are sincere, others are attempts to toss sand into the machinations of pro-tunnel governments as the controversial project, set to open by the start of 2016, moves forward.

It turns out the Seattle project includes engineering solutions that the tunneling industry devised in response to catastrophes in other parts of the world.

"We're looking at a tunnel that's providing state-of-the-art technologies," said project manager Linea Laird.

But tunnels, by their nature, have hazards. Which matter most, and what do they mean for motorists?

Emergency escape doors will be built every 650 feet. On the other side would be concrete-sheltered corridor, designs show. People could then walk to daylight at the Sodo or South Lake Union portals of the 1.7-mile tunnel