01/27/2021
Flanders Crossing Bridge
With the opening of the 4.25-mile-long I-405 freeway in 1969, the neighborhoods left standing on either side of the high-speed freeway needed a safer connection for pedestrians and bicyclists. It took more than a half-century to build a solution, the Flanders Crossing. As an alternative route to Interstate 5 through Portland, the I-405 is one of the city’s busiest thoroughfares. In 2007, the City of Portland identified NW Flanders Street as an alternate seismic-resilient route for emergency vehicles following an earthquake. The Flanders Crossing Bridge may be the only bridge still standing among the 29 overpasses spanning I-405 between the Fremont and Marquam bridges after a large earthquake. See “Count the Bridges Field Trip,” p. 151 in The Big & Awesome Bridges of Portland & Vancouver, A Book for Young Readers and Their Teachers.
Opened for use: April 2021 (date to be announced)
Location: Near Downtown Portland over Interstate 405 at Northwest Flanders Street between Northwest 15th and 16th avenues; connects the Pearl District (east) and Northwest District (west) neighborhoods about 15 blocks west of the Willamette River
Purpose: To provide a safe crossing over the I-405 between two busy and often congested Portland neighborhoods.
Named for: Flanders Street
Type: Steel Parker pony truss
Color: Gray
Unusual feature: Truss bridges were the go-to type for bridge building in America during the late 19th century and much of the 20th century. The Flanders Crossing Bridge mirrors that tradition and is distinct for its clean lines and tessellation (repeating patterns). Some say the bridge is an example of structural art. The paint colors for the railing and protective fencing were chosen by the Pearl and Northwest District neighborhood associations. Two twelve-wheel trailers and two cranes were used to roll and swing the the 355,000-pound (177.5 tons) steel truss into place over I-405 on January 23, 2021.
Designed for: Non-motorized vehicle use and, in case of an earthquake, by emergency vehicles
Length: 199 feet
Elevation over I-405: Between 18 and 21 feet
Width: 24 feet with six feet for pedestrians on either side and 12 feet for cyclists in the middle (the bike and pedestrian areas will be at the same grade but marked with stencils painted on the deck)
Structural Engineers: Contech Engineered Solutions, West Chester, OH, and Portland Bureau of Transportation’s engineering team led by Cameron Glasgow and Frederick Mangubat
Foundation Engineers: Shannon & Wilson, Portland
Electrical Engineers and Lighting Designers: Kittelson & Associates, Portland
Steel Fabricator: Contech Engineered Solutions at their shop in Minnesota
Contractor: Wildish Construction, Eugene, OR
Owned and maintained by: Portland Bureau of Transportation
Earthquake resistant: Yes
Cost: $9.5 million
