Thirty-three years after the Sunset Boulevard Bridge over Latah Creek opened to traffic in 1913, one of its designers came back to Spokane and reminisced about the project.
“The city was looking well ahead into the problems of highway transportation when it built that bridge,” said Ernest Howard, the bridge designer who was in town in 1946 for a meeting of civil engineers. “That was long before the day of widespread use of the automobile.”
Nearly a century after the bridge went up, city officials say that while the design was forward-thinking for 1913, the structure needs an update.
While the bridge’s seven pairs of massive arches remain strong, the deck has suffered considerable wear, and some beams underneath have eroded enough to expose rebar. Perhaps more problematic, only the bridge’s middle portion, designed for streetcars, is considered strong enough for modern traffic. The city closed the outer lanes a few years ago because of wear and the weaker deck structure holding up the sides.
“It was never designed for the loads of today’s driving public,” Spokane Street Director Mark Serbousek said. But he stressed: “It’s still safe to go over the top of.”
The city contracted last year with CH2M Hill to study the bridge and its possible rehabilitation. The $631,000 study, paid for with a federal grant, is expected to be finalized in the next few weeks.
Serbousek said he suspects that, as with the recent reconstruction of the Monroe Street Bridge, the large arches of Sunset Boulevard Bridge can be saved. But the deck may have to be torn off and replaced.
The study will consider future light rail; whether room should be made for bike lanes; and how many car lanes a rebuilt bridge should support.
“Right now it’s working well with two,” said Lisa Malstrom, the city’s senior engineer in charge of bridge inspection and maintenance. “At what point might we need four lanes back on the bridge?”
City officials say whether they move forward with rehabilitation would depend on finding federal or state money to pay for it. The 1913 structure cost about $422,000, which the city financed with bonds.
The Spokane Transit Authority has requested that any long-term rehabilitation of the bridge make it strong enough for light rail, STA spokeswoman Molly Myers said. An STA plan that considers a light rail system suggests placing a line to Airway Heights along the bridge. Myers said the STA provides about 4,000 bus rides daily on two routes that use the bridge, but light rail would be extremely unlikely on the bridge for at least a couple of decades.
The STA’s goal is to prevent a “decision that would prohibit options down the road,” she said.
Councilman Jon Snyder said the city pursued the grant for the bridge study in part because of a state proposal for improving the safety of U.S. Highway 195 that the city feared would result in diverting traffic to the deteriorating Sunset bridge.
Snyder said any rehabilitation should preserve the bridge’s design.
“To me it’s like the sister bridge to the Monroe Street Bridge, and that rehabilitation was a massive success,” Snyder said.