Pittsburgh's I-579 'cap' will cause traffic disruptions

More than 2,000 daily commuters accessing Downtown Pittsburgh via a ramp from northbound I-579 will have to find alternative routes for the next two years during construction of a “cap” linking Downtown and the Hill District.

PennDOT announced that a ramp leading from the Liberty Bridge to Seventh Avenue would close Friday for the construction of four piers that will help support the $30 million cap. Approximately 2,250 vehicles use the ramp daily. The ramp will be closed for 700 days, according to PennDOT.

Pittsburgh announced that the northbound lane of Chatham Street between Centre Avenue and Bigelow Boulevard would also close for the project, starting on Monday. It is scheduled to reopen in December.

The long-awaited cap project, funded by federal, state and local governments and charitable foundations, will feature a three-acre public park bordered by Bigelow Boulevard and Centre Avenue and Chatham Street and Washington Place. It’s scheduled for completion in 2022.

The park will feature paths for walkers and bicyclists from the neighborhood to Downtown, displays that tell the history of the Hill, artwork by local artists and stormwater mitigation, including rain gardens. The project includes upgrades to retaining walls, road reconstruction, drainage improvements, traffic signals, highway lighting and landscaping.

It will complement the Penguins’ plans for redevelopment of the adjoining 28-acre former Civic Arena site. Dubbed the Centre District, the $750 million project will be a residential, retail, office and entertainment complex. Construction is expected to begin this fall.

The cap foundation includes 42 caissons drilled to a depth of 35 feet and 42 concrete columns that will support what is essentially a concrete bridge over the highway, according to PennDOT.