20th Avenue NE Bridge

The 20th Avenue NE Bridge, which some also call the Ravenna Park Bridge, crosses a ravine in Ravenna Park in Seattle [1]. Frank M. Johnson designed it while Arthur Dimock held the post of city engineer [1]. The structure went up in 1913, and it is a three-hinged steel bridge with a lattice arch [1]. It appears both in the National Register of Historic Places and on the city's list of landmarks [1]. The span runs 354 feet, with an arch of 250 feet that rises 41.5 feet from its footings, the ravine floor falling away lower still [1]. Across the top it carries an 18-foot reinforced concrete roadway and a 5-foot sidewalk [1]. A four-month trial began on March 11, 1975, shutting the bridge to vehicles [1]. It fell short of the arterial standards of that time, and the cost of bringing it up to them was judged prohibitive [1]. The trial worked, and vehicles have stayed off it since, though people on foot and bicycles still use it [1].