Interstate 579 and the Liberty Bridge

Interstate 579 North
Upon exiting the Liberty Tunnel, which carries Liberty Avenue under Mount Washington, the roadway crosses the Monongahela River via the Liberty Bridge. From there, the Liberty Bridge changes into a freeway configuration, which becomes Interstate 579 after crossing over Interstate 376 (Penn-Lincoln Parkway East) and interchanging with the Boulevard of the Allies (Pennsylvania 885). Here is a view of the Liberty Bridge on northbound as Liberty Avenue crosses over the Monongahela River. These are the first signs to advise of the pending Interstate 579 freeway. Photo taken 5/25/02.
Looking east on the Monongahela River from the Liberty Bridge is this view of the river. The South 10th Street Bridge (yellow suspension bridge) and Birmingham Bridge (arch bridge) are both visible toward the east. To the west (not shown), the Monongahela River flows into the Allegheny River near Point State Park, where two rivers merge to form the Ohio River. Photo taken 10/14/01.
Downtown Pittsburgh looms ahead as the Liberty Bridge crosses the Monongahela River. The bridge is not Interstate standard, as it is undivided and has lane signals that govern the flow of traffic on the bridge. Since there are four lanes in total, the configuration can be four lanes in one direction, three lanes in one direction and one lane in the other direction, or two lanes in each direction. Construction may restrict the number of available lanes. On this day, the configuration was two lanes in each direction. Upon reaching the north bank, the Liberty Bridge will transition directly into Interstate 579 northbound, and the first exit will be the ramp to Pennsylvania 885 (Boulevard of the Allies). Use the Boulevard east to Interstate 376 (Penn-Lincoln Parkway East) eastbound to Monroeville and the Pennsylvania Turnpike. Photo taken 5/25/02.
The speed limit on the Liberty Bridge is 40 miles per hour. A steel cantilever bridge, all of the support structure is below the bridge rather than above the bridge. The substructure is visible from Interstate 376, which passes under the bridge on the north bank of the Monongahela River. Opened in 1928, the Liberty Bridge predates the construction of the Crosstown Boulevard, which preceded modern Interstate 579, by several decades.1 The Liberty Bridge is an unsigned state route. Continuing north on the bridge, this sign identifies the first three exits along northbound Interstate 579: Pennsylvania 885/Boulevard of the Allies to Interstate 376 east; 6th Avenue (to Mellon Arena); and 7th Avenue. Photo taken 5/25/02.
While on the northbound Liberty Bridge, the unmistakable skyline of downtown Pittsburgh comes into view. While different from the angle seen on northbound Interstate 279, it is no less dramatic. Photo taken 10/14/01.
The Liberty Bridge reaches its end at the offramp to Pennsylvania 885 (Boulevard of the Allies). Interstate 579 begins here, at this gore point. Use the left lane to begin traveling north on Interstate 579, and use the right lane to exit to the Boulevard of the Allies to downtown (westbound) and Oakland, Schenley Park, and Interstate 376 (eastbound). The overhead pull-through sign is the first reassurance marker for Interstate 579 northbound. Photo taken 5/25/02.
Interstate 579 South
Immediately after departing southbound Interstate 279, southbound Interstate 579 crosses the Allegheny River via the Veterans Bridge. Unlike most other bridges in the downtown area, there is no visible superstructure on the Veterans Bridge for motorists on Interstate 579. The bridge is more like a concrete skyway. It was built in 1987, the year that Interstate 579 was fully constructed.2 The skyline of downtown Pittsburgh comes into view immediately upon crossing the river. Photo taken 5/25/02.
Looking west from the southbound lanes of Interstate 579 on the Veterans Bridge, the black truss bridge carries a railroad over the Allegheny River. Beyond that, the 9th Street Bridge, the 7th Street Bridge, and the Roberto Clemente Bridge each cross the river via yellow suspension bridges. The Roberto Clemente Bridge is named for Puerto Rican Roberto Clemente, who played Pittsburgh Pirates baseball between 1955 and 1972, a career that was marked with Golden Gloves, a Most Valuable Player award, over 3,000 hits, and an excellent batting average. In 1972, Clemente died in a plane crash, when he was en route to Nicaragua to provide earthquake assistance.3 Today, his bridge connects PNC Park (home of the Pirates) with downtown Pittsburgh. Beyond the three suspension bridges is the Interstate 279 Fort Duquesne Bridge. Photo taken 5/25/02.
Still on the Veterans Bridge, southbound Interstate 579 approaches its first exit, Exit 2, 6th and 7th Avenues. Use 6th Avenue to access Mellon Arena and 7th Avenue west into downtown Pittsburgh and toward the Convention Center. This interchange also serves as the western terminus of Pennsylvania 380, which travels west via Bigelow Boulevard toward eastern Pittsburgh and Penn Hills. Photo taken 5/25/02.
The area around the 6th Avenue/7th Avenue interchange along southbound Interstate 579 is a cavalcade of ramps and transitions. Interstate 579 reduces to two lanes in each direction, while the connection ramp to 6th Avenue and 7th Avenue splits (as seen in the photo to the right of the mainline). Photo taken 5/25/02.
This is the final reassurance shield assembly along southbound Interstate 579 as the Crosstown Boulevard approaches the ramp to Interstate 376, the Penn-Lincoln Parkway East. Note that both of the Interstate shields used on this sign contain the state name; it is likely that neither shield is still in place, considering that most Pennsylvania Interstate shields now are neutered. Photos taken 5/25/02.
Interstate 579/Crosstown Boulevard travels below grade as it passes Mellon Arena to the east and downtown to the west. The next exit along southbound Interstate 579 is Exit 1B, Interstate 376 and U.S. 22-30. U.S. 22-30 are not signed on any approach signs, but they are shown on most reassurance shield assemblies. Photo taken 5/25/02.
The right lane becomes exit only for Pennsylvania 885/Boulevard of the Allies east to eastbound Interstate 376/U.S. 22-30/Penn Lincoln Parkway East to Oakland, the University of Pittsburgh, Schenley Park, Squirrel Hill, Point Breeze, and Frick Park. Interstate 376 ultimately connects to the Pennsylvania Turnpike (Interstate 76) in Monroeville. There is no connection from southbound Interstate 579 to westbound Interstate 376. The left lane connections Interstate 579 with the Liberty Bridge, in preparation to cross the Allegheny River. Photo taken 5/25/02.
The single lane for Interstate 579 passes under the Boulevard of the Allies (Pennsylvania 885), and a second lane will join Interstate 579 traffic as they enter the approach to the Liberty Bridge. Interstate 579 will end just ahead, after passing through this maze of ramps. Photo taken 10/01.
Traffic from southbound Interstate 579 and the Boulevard of the Allies (Pennsylvania 885) each bring a lane onto the Liberty Bridge. The point where these two ramps merge together is the southern terminus of Interstate 579; the Liberty Bridge is a secondary state route (numbered 3069 based on a white milepost marker, not photographed) that is the connection between downtown and Mount Washington and the Liberty Tunnel. Note that the bridge is not divided so that reversible lanes can be implemented during commute hours. Photo taken 5/25/02.
This variable message sign, located on the southbound Liberty Bridge, shows the lane assignments for destinations reached via the Liberty Tunnels. On this day, the left lane may be used for Truck U.S. 19 (Liberty Avenue) south to Dormont, and the right lane connects to Pennsylvania 51 (Saw Mill Run Road) south to Uniontown and north to West End. In addition, there is a right turn at the end of the Liberty Bridge that connects to Mount Washington via the P.J. McArdle Roadway. The McArdle Roadway travels northwest as its ascends Mount Washington, serving the neighborhoods on top of the mountain as well as several scenic vistas of downtown and the three rivers. Photo taken 10/01.
Use the Liberty Tunnel southbound to connect to Truck U.S. 19 and Pennsylvania 51. The tunnel passes under Mount Washington, while the McArdle Roadway (right turn) offers a connection to the top of the mountain. The speed limit remains at 40 miles per hour as it enters the tunnel, which is among the longest in Pittsburgh at over a mile long. The two tubes that constitute the Liberty Tunnel system were constructed by 1923.4 Photo taken 5/25/02.
A left turn is also available at the portal to the Liberty Tunnels. This turn is not shown on any of the overhead signs, but it is afforded at the traffic signal that regulates traffic at the McArdle Roadway, which connects to South Shore and South Side, as well as Pennsylvania 837 (Carson Street). This view of the Liberty Tunnels is taken from the left turn made at the traffic signal. Photo taken 5/25/02.
Interstate 579 scenes
This Interstate 579 shield is found on Pennsylvania 380 (Bigelow Boulevard) in front of the Mellon Arena. It may have been removed, but we have not been back to field check its status. Photo taken 5/25/02.
On northeastbound Bigelow Boulevard is this overhead sign as the road passes over Interstate 579/Crosstown Boulevard. The left lane continues northeast to connect to Interstate 579 north to Interstate 279 (Parkway North) and Pennsylvania 380 (Bigelow Boulevard) east. Pennsylvania 380 generally follows former U.S. 22-30 before they were rerouted onto Interstate 376. Photo taken 5/25/02.


  1. Liberty Bridge by Bruce Cridlebaugh
  2. Veterans Bridge by Bruce Cridlebaugh
  3. Roberto Clemente Biography from the official webpage
  4. Liberty Tunnels by Bruce Cridlebaugh

Page Updated April 16, 2005.

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