Bridge options on deck
Sullivan project might involve temporary span
Wednesday night’s public meeting on construction options for the west Sullivan Road bridge drew a crowd of city staff, a group of Boy Scouts working on a badge and at least one contractor, but few residents.
More than 25,000 vehicles a day use the bridge, which is located next to Inland Asphalt, a Central Pre-Mix Concrete plant and the Spokane Valley Industrial Park. About 24 percent of the daily traffic is large trucks, said Spokane Valley project manager Craig Aldworth.
“We have a very high traffic load,” Aldworth said. “They’ve noticed cracking in the girders and problems with the deck.” The flow of the river is also scouring away the earth around the bridge’s footings, he said.
The bridge, which carries southbound traffic, was built in 1951 and is rated as structurally deficient and weight restrictions were imposed last year. Temporary repairs are under way that should allow the restrictions to be lifted. “All we’re doing is reinforcing the girders,” Aldworth said. “It’s pretty much a Band-Aid for the bridge.”
The estimated cost to replace the bridge is nearly $20 million. The city has already received $10 million in grants and is working on the design and environmental permitting while looking for additional funding.
Preliminary work on the new, four-lane bridge is being done by CH2M Hill. The wider bridge should eliminate traffic backups caused by southbound traffic trying to turn east or west on Indiana, said CH2M Hill project manager Jim Dingfield. Engineers are considering how best to build the new bridge while maintaining traffic flow, as well as access to local businesses, the Centennial Trail, Sullivan Park and the Spokane River.
Dingfield said that when the city rebuilt the Barker Road bridge, it was closed completely. “That’s not an option here,” he said.
Four construction options are being considered; three include building a temporary bridge.
• The first option is to build a new two-lane bridge immediately to the west of the old one, and divert traffic to it while the old bridge is torn down and replaced. That would create tight quarters for the contractor, Dingfield said.
• The second option is to build a temporary bridge to the east to use for northbound traffic and then route southbound traffic over the current northbound bridge.
• The third option is to build a full, four-lane bridge to the west and then roll it into position once the old bridge is torn down and new supports are installed. “It’s pretty high tech,” Dingfield said. “It has been done in a number of places, but there are risks. Not all contractors could do it.”
• The fourth option would look at removing the sidewalk on the northbound bridge and having it carry one lane of northbound traffic and two lanes of southbound traffic. If that option was selected, a way would have to be found to get pedestrians and bicyclists across the river, Dingfield said.
Options for keeping the Centennial Trail open include building a “hard hat” over the trail to protect trail users or rerouting users up onto Indiana to cross Sullivan.
The city hopes to start construction in spring 2014. The design work has not begun yet and since crews will be working in the Spokane River the environmental permitting alone is expected to last until the summer of 2013, said CH2M Hill assistant project engineer Mark Brower.
The project will be put out to bid that fall so work can begin in the spring during the “fish window” that allows river construction after fish spawning is complete, he said.
A man in the audience asked if there will still be access to local businesses during construction. Aldworth said it may be necessary to restrict east turns to Indiana from southbound Sullivan.
“Being able to turn left southbound on Indiana is very important,” said Spokane Valley Fire Department Deputy Chief Larry Rider. The department has a station on Sullivan on the north side of the river. Rider said he favored the fourth option and suggested that a permanent pedestrian suspension bridge could be built across the river. “It looks to me like you have way too many penetrations in to the river that cost too much and take too much time,” he said.
The key is to get the project done as quickly as possible, Rider said. “Barker was terrible for us,” he said. “Barker took a century to build.”
Dingfield said the construction would probably require taking over a small section of Sullivan Park. “It is slope area now with trees on it,” he said. The park would probably be improved to make up for the lost land, he said.