Jonathon Hulton Bridge

Location: Allegheny County, PA between Harmar Township and Oakmont (view map)
Type: Thru truss (Pennsylvania truss, with Parker truss approaches)
Year Built: 1909, rehabilitated ca. 1992 and 2000
Crosses: Allegheny River

To most residents in the Pittsburgh area, the Hulton Bridge is noteworthy due to its lavender color (it was painted that shade from green in an early 1990's rehabilitation). The bridge is significant for a lot more. It is the first major bridge designed by the Allegheny County Department of Public Works. It consists of 1,544 feet of trusses, longer than any other thru truss in the county. The bridge's 505 foot main span is in the top 50 of the longest simple truss spans in North America. The main span is skewed, though the rest of the surrounding trusses are not. The bridge is a rare example of a Pennsylvania truss. By 2015 there will only be about 10 Pennsylvania truss bridges remaining in the commonwealth. Furthermore, due to recent demolitions, the bridge is the oldest active vehicular truss bridge over the entire Allegheny River!

Despite its historical significance and relatively good condition (the bridge is well-maintained and is not structurally deficient), the Hulton Bridge is scheduled for replacement in 2012, pending on funding. The narrow two-lane bridge is a bottleneck and is frequently congested. There is no reasonable solution to increase capacity except for building a new bridge. The new bridge is to open in 2014 alongside the current bridge.

As an alternative to demolition, students at Carnegie Mellon University studied converting the current bridge into a pedestrian bridge to connect Oakmont to the proposed Allegheny River Trail on the north bank of the river. In that way, Oakmont would becomes one of the trail towns connecting the greater Pittsburgh area with Washington D.C. As a result, tourists and trail users alike will be drawn to Oakmont to see the bridge and to walk/hike/bike the trail, as well as for shopping and dining on the main streets nearby. The converted bridge could also be used for special events, such as weddings, art festivals, and Oakmont Country Club tourism, especially leading up to or during the upcoming US Opens.

The students surveyed area residents through the Chamber of Commerce. Responses indicated that almost 90% of the residents agree that money used to demolish the bridge should be transferred to convert and rehabilitate the bridge for pedestrian use. Taxpayers are covering $6 to $10 million to demolish the bridge. It costs $300,000 to convert the bridge to pedestrian use. However, the price will end up costing much more due to repairs and maintenance of the current bridge as well as potential design changes to the proposed replacement bridge. However, the positive economic impact from the pedestrian bridge may outweigh the maintenance costs. Survey responses also indicate that 70% of the residents will walk or bike across a converted bridge more than they do currently on the sidewalk of the existing bridge, and 44% of residents also reported they would volunteer to help an effort to convert the bridge.

The only way the project may go forward is if an organization is interested in assuming ownership of the existing bridge. Please contact bridgemapper@gmail.com for more information about the project.

See the students' final presentation here. (PowerPoint presentation .ppt file)

See the ASCE Newsletter featuring the bridge here.