Transportation :: Bridges and Structures
I-84 Graham Road Bridges
The DEA team provided designs to replace two aging Interstate 84 bridges for the Oregon Department of Transportation in Troutdale, Oregon. The bridges are set at an interchange that experiences a significant freight presence, as well as a high volume of pedestrians. To accommodate the freight industry and travelling public, the project focused on increasing the vertical clearance, improving safety, reducing maintenance attention and costs, and minimizing traffic interruptions. To fully achieve the project goals, DEA provided designs for a roadway widening that added a vehicular lane, expanded a bike lane, and added a sidewalk and sidewalk ramps. To further support infrastructure improvements, DEA provided other services including stormwater management, erosion control, signing, striping, utility coordination, and construction engineering support.
One of the project challenges was to minimize traffic and pedestrian disruption during construction. To accommodate traffic on I-84, we used a temporary detour bridge in the median to maintain two lanes of traffic in each direction during demolition and construction of each bridge. Pedestrian access during construction was a critical component because there were no existing accessible facilities, but pedestrians had made an unofficial route out of necessity. The DEA team tackled the pedestrian needs by developing a staging plan that provided protected access during the majority of construction activities and utilized a feasible detour route during closures.