I-579 begins at an interchange with
Pennsylvania Route 885 (PA 885;
Boulevard of the Allies) and the approach to the
Liberty Bridge over the
Monongahela River in
Downtown Pittsburgh, heading to the north-northeast as a four-lane
freeway. At the southern terminus, the highway has a northbound exit and southbound entrance providing access to 6th Avenue and
Forbes Avenue near
Duquesne University. The road passes several skyscrapers as it comes to an interchange at Centre Avenue with a northbound exit and southbound entrance that provides access to the
PPG Paints Arena. Immediately following is a left exit in the northbound direction and a southbound entrance that connects to 7th Avenue that serves the
David L. Lawrence Convention Center. At this point, I-579 runs to the west of the former site of the
Civic Arena and comes to the
PA 380 interchange, a northbound exit and southbound entrance, in addition to a southbound exit and northbound entrance accessing 6th Avenue and 7th Avenue. The freeway turns north as it passes over railroad tracks to the east of
Union Station, the
Amtrak station serving Pittsburgh. Here, it is seven lanes total with three travel lanes in each direction and two reversible
high-occupancy vehicle lanes (HOV lanes) in the center. The HOV lanes connect to Bedford Avenue near the Civic Arena at the south end. The highway turns northwest as it crosses the
Allegheny River on the
Veterans Bridge. A short distance after the bridge, I-579 ends at an interchange with
I-279/
US Route 19 Truck (US 19 Truck) and
PA 28, at which point the route merges into northbound I-279 with ramps to and from westbound PA 28. ==History==