Oleson Road Bridge over Fanno Creek

Q: The bridge looks fine. Why is the County replacing it?

A: There are several reasons for the bridge replacement:

  • Periodic flooding causes road closures that block traffic including emergency services, requiring all travelers to reroute around the unanticipated closure.

  • The flooding results in increasing damage to the bridge’s wooden structure.

  • The existing bridge does not meet current design standards. The travel lanes narrow at the bridge and do not meet standard lane widths. The guardrail does not meet current standards.

  • The bridge is considered “Structurally Deficient.” Over the years the County has done various repairs to the bridge including replacing the wooden caps holding up the bridge deck and repairing and replacing the guardrail. The County is continually monitoring the deteriorating condition of the wooden beams under the bridge deck due to repeated water damage.

  • Eventually the bridge will deteriorate to a point where replacement is mandatory. If we were to wait until that point, replacement of the bridge would have occurred on an unanticipated schedule. It would have required a longer closure that would have had to last through the design phase of the new bridge, hiring of a contractor and finalizing of the construction schedule.

  • It is in the public’s best interest to proactively replace the bridge. This project allows us to plan out the bridge replacement in a cost-effective manner and review all possible avenues to mitigate impacts to the traveling public and near by residents and businesses.



Q: Why does the road need to be closed at the bridge for eight months?

A: That section of Oleson Road at Fanno Creek has very limited physical space to work in while the contractor replaces the bridge over Fanno Creek. There is not enough width available to maintain the existing bridge and construct a new bridge simultaneously. The bridge and roadway leading up to both ends of the bridge will also need to be raised seven feet, additionally limiting the work area.

During the closure, a narrow temporary pedestrian and bicycle bridge will be placed on the side of the road allowing walkers and bicyclist’s access through the project work site during construction.

The road will be blocked off approximately 160 feet north of the bridge and approximately 230 feet south of the bridge.

Roadway access to the apartments and businesses will be available during construction.

We do not anticipate the closure taking longer then eight months and will make sure the contractor stays on schedule so we can reopen the roadway on time or sooner, if possible.



Q: Will the traffic signals in the area be adjusted during the road closure to move motorists efficiently along the detour and along additional routes that motorists may choose to take?

There are four public agencies in the area that control the traffic signals adjacent to the project and along the detour route (ODOT, Beaverton, Portland and Washington County). All four agencies are prepared to make adjustments to their signals as soon as the closure begins, if needed. They will evaluate the traffic flow to make sure the adjustments are working, including at the start of the school year. If specific traffic problems are reported, all of the agencies are prepared to review the problems for appropriate corrective actions.


What hours will the contractor work?

Currently, the contractor is working Monday through Thursday, ten hour days. This is common for road and bridge construction in order to utilize the longer days to get as much work done each day as possible. The contractor may occasionally work on Friday and Saturday as needed to complete certain tasks and/or to accommodate material delivery or the use of special equipment. 

The noise ordinance allows work to be performed between 7 a.m. and 7 p.m. Monday through Saturday.