Interstate 579 (abbreviated I-579) is a north–south Interstate Highway entirely within Pittsburgh, Pennsylvania. At 1.57 mi (2.53 km) long, it is short but not the shortest signed Interstate, a title which belongs to I-878 in New York State. I-579 is also known as the Crosstown Boulevard since it crosses the backside of Downtown Pittsburgh.
Construction on Interstate 579 was not completed until 1989, with the opening of the Veterans Bridge, and the opening of Interstate 579 was concurrent with the opening of an extension of Interstate 279 into the North Hills region of the Pittsburgh metropolitan area.
In the past, this was first Interstate 876 and then Interstate 479 prior to becoming Interstate 579. The change from 876 to 479 was because it didn't connect to I-376 (then I-76), and then it was changed to 579 because it only connected to an interstate at one end.
I-579 begins at an interchange with 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 Consol Energy Center. 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 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 19 Truck and PA 28, at which point the route merges into northbound I-279 with ramps to and from northbound PA 28.