Bull Run River (Bull Run Road) Bridge Replacement

The county has invested in funding the beginning stage of engineering design for a new bridge. So far we have 30% design plans that analyze the best location to build a replacement bridge based on cost and environmental requirements. Road, bridge and seismic criteria will follow state and federal standards.

Based on average daily traffic and anticipated future growth, standards require 11-foot lanes, with 6-foot paved shoulders on each side of the road, and 8-foot paved shoulders on each side of the bridge.

Three alternatives are being considered for the new bridge location. These options consider factors such as the horizontal and vertical alignments, slopes and landslide risk, connection to the road and the length and sharpness of the curves, drainage flow, water surface and flood projections, potential areas for construction equipment, and the costs for potential right of way, environmental and construction requirements.

We have conducted studies to analyze the water levels and forecast large flood events, and to analyze the stability of the material underground and the feasibility of specific construction methods. We considered several bridge types for the future design. A 250-foot single span steel box-shaped bridge is the only type of structure considered to be possible with the estimated budget, design criteria and site limitations. 

Yes, for vehicles that weigh less than 12 tons. While the bridge needs to be replaced because of age, usage and vehicle load restrictions, recent engineering calculations show the bridge is adequate to carry the posted weight. It is still safe to cross the bridge within the weight limit restrictions, but it is deficient in many other respects and may need to be closed within the next 5 to 10 years.

We will continue to monitor the structural integrity of the bridge along with the Oregon Department of Transportation. Further restrictions are possible. If the bridge is found to be unsafe in an upcoming inspection, we will close the bridge.  

Heavy loads can impact the structure and safety of bridges by causing significant stresses to the bridge components resulting in cracking or structural failure. To reduce the stresses of the wrought iron components of the Bull Run Bridge, we must limit heavy loads from crossing until the bridge can be replaced. If we do not limit the heavy loads from trucks, we risk closing the bridge entirely until funds can be found to replace it.
 

One vehicle crossing Bull Run Bridge at a time in the center of the bridge reduces the weight of traffic, has less impact on the structure and will help preserve the remaining life of the bridge. This change is expected to be permanent until the bridge is replaced.

A recent inspection of the bridge identified some components in worse condition compared to the prior inspection. The Oregon Department of Transportation developed a new load rating for the bridge based on the latest conditions of the bridge, resulting in new weight restrictions.

Over time, the natural processes of deterioration and constant use take their toll on bridges. The deterioration and use can leave a bridge with less capacity than it was originally designed and built. Also, the size and weight of freight and emergency vehicles has been increasing steadily. Because most of Oregon’s bridges were not designed for current vehicle sizes and weights, many of our aging bridges cannot safely carry all modern loads. These bridges must be posted to limit traffic to the loads they can safely carry without impairing structure or safety.

Heavy loads can impact the structure and safety of the bridge by causing significant stresses to the bridge components that can result in cracking or structural failure. To reduce the stresses on the wrought iron components of the Bull Run Bridge, we must limit heavy loads from crossing until the bridge can be replaced. If we do not limit the heavy loads from trucks, we risk closing the bridge entirely until funds can be found to replace it. 

The detour from Sandy to the Bull Run Bridge is 35 miles long and takes about 60 minutes traveling from US 26, to Burnside Road, to 232nd Ave, to OR 84/30, to Corbett Hill Road, to Evans Road, to Gordon Creek Road to Bull Run Road.

Emergency vehicles that weigh 12 tons or less are allowed. Based on load-rating test, we can allow standard two-axle fire trucks and three-axle water tenders to cross the bridge, with the conditions that they come to a full stop before crossing and then travel one at a time in the center of the bridge at less than 5 miles per hour. Ambulances and small brush fire vehicles can cross without restrictions. Other larger fire trucks are too heavy to cross the bridge.

If you witness trucks crossing the bridge that you think could be over 12 tons, you may report the incident by calling the Clackamas County Sheriff’s Office non-emergency number at 503-655-8211.