SEATTLE — The Seattle Department of Transportation (SDOT) plans to limit heavy vehicles in Pioneer Square starting in May, citing structural weaknesses in the underground structures beneath the historic area.
Trucks and buses over 10,000 pounds will no longer be allowed to park or drive in the lane closest to the sidewalk. Officials say this is because of concerns with brick and mortar walls at the edge of street and sidewalk, leftovers from the rebuild after the Great Seattle Fire of 1889 when the street level was raised.
Today, these walls support the world above.
“The underground is simply this: a dead space. Open space between the block of buildings and the road itself,” said Mike Daugherty, a guide for Beneath the Streets.
Daugherty leads tours beneath Pioneer Square and has a firsthand look at the structures in question.
“This is the original ground floor of Seattle,” he said. “You walked down not to a basement, this is the original ground floor.”
Daugherty’s tour explores the hollow spaces beneath the sidewalks.
“Many of these street support walls were built from brick, rubble, and mortar over 100 years ago,” SDOT wrote in a blog post. “These underground walls were not designed to support the weight of today’s large trucks and buses or to meet modern earthquake safety standards.”
SDOT said it discovered these deficiencies when the Alaskan Way Viaduct closed and engineers started a new study as bus routes moved onto 1st Avenue. The study led them to discover “new structural vulnerabilities” not previously identified.
The area remains for safe for normal cars, pedestrians, and those touring the underground, SDOT said.
Still, some business owners in the area have concerns. Angela Williams owns Luigi’s Italian restaurant.
“We do get a lot of deliveries, along with our neighbor 7-11,” she said.
Williams worried about trucks losing easy access to her business, and about a lack of parking in the area.
“Very frustrated,” she said. “The parking is at a marginal premium right now, and they turned 1st Ave. with the bus situation into a freeway.”
SDOT plans to relocate some commercial load zones over the summer.
Daugherty said he’s glad to see the city preserving history and his livelihood.
“Anytime someone wants to give some respect to something old, I think that’s a good idea,” he said.
The city plans to continue inspecting the walls to develop a repair plan and will work with businesses to install monitoring equipment.