The bridges of Pittsburgh play an important role in the city's transportation system. Without

bridge A bridge is a structure built to Span (engineering), span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the path underneath. It is constructed for the purpose of providing passage over the obstacle, whi ...

s, the Pittsburgh region would be a series of fragmented valleys, hillsides, river plains, and isolated communities. A 2006 study determined that, at the time,

Pittsburgh Pittsburgh ( ) is a city in Allegheny County, Pennsylvania, United States, and its county seat. It is the List of municipalities in Pennsylvania#Municipalities, second-most populous city in Pennsylvania (after Philadelphia) and the List of Un ...

had 446 bridges, though that number has been disputed. With its proximity to three major rivers and countless hills and

ravine A ravine is a landform that is narrower than a canyon and is often the product of streambank erosion. Ravines are typically classified as larger in scale than gullies, although smaller than valleys. Ravines may also be called a cleuch, dell, ...

s, Pittsburgh is known as ''"The City of Bridges"''.

History

Pittsburgh's first river bridges, made of wood and long since replaced, opened in 1818 at Smithfield Street and 1819 at Sixth Street (then St. Clair Street). The city's oldest in-service bridge is the current

Smithfield Street Bridge The Smithfield Street Bridge is a lenticular truss bridge crossing the Monongahela River in Pittsburgh, Pennsylvania, USA. The bridge was designed by Gustav Lindenthal, the engineer who later designed the Hell Gate Bridge in New York City. ...

, which opened in 1883; it was designated a

National Historic Landmark A National Historic Landmark (NHL) is a National Register of Historic Places property types, building, district, object, site, or structure that is officially recognized by the Federal government of the United States, United States government f ...

in 1976. Pittsburgh waged a massive road and bridge building campaign from 1924 to 1940; most of Pittsburgh's oldest major bridges date from this period. The coming of the

Interstate Highway System The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, or the Eisenhower Interstate System, is a network of controlled-access highways that forms part of the National Hi ...

triggered more construction in the second half of the twentieth century, as vehicular speed and throughput requirements increased. The result of more than 100 years of bridge building is a collection of most of the major types of bridge (

suspension Suspension or suspended may refer to: Science and engineering * Car suspension * Cell suspension or suspension culture, in biology * Guarded suspension, a software design pattern in concurrent programming suspending a method call and the calling ...

cantilever A cantilever is a rigid structural element that extends horizontally and is unsupported at one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cantilev ...

arch An arch is a curved vertical structure spanning an open space underneath it. Arches may support the load above them, or they may perform a purely decorative role. As a decorative element, the arch dates back to the 4th millennium BC, but stru ...

, etc.), mostly built from locally produced

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

, including about forty river spans. Many of the bridges in the Downtown area are colored Aztec Gold, either constructed as such or painted afterward, to match the city's official colors of black and gold. A few old and out-of-service bridges, such as the

Hot Metal Bridge The Hot Metal Bridge is a truss bridge in Pittsburgh, Pennsylvania, that crosses the Monongahela River. The bridge consists of two parallel spans on a single set of piers: the former Monongahela Connecting Railroad Bridge, built in 1887, on th ...

(which stood dormant until reopening as a passenger bridge in the year 2000), are exceptions to this rule.

Degrading bridge conditions

According to a 2011 study by Transportation for America, 1,194 bridges in the Pittsburgh area—or 30.4%—were deficient, the highest proportion in the nation. On February 8, 2008, the

Birmingham Bridge The Birmingham Bridge (known during construction as the Brady Street Bridge) is a bowstring arch bridge that is located in Pittsburgh, Pennsylvania and spans the Monongahela River. It connects East Carson Street on the South Side with Fifth ...

suffered a failure of its rocker bearings, causing the deck to drop eight inches, prompting a closure of the bridge. The bridge was repaired and fully reopened on September 8, 2008. On January 28, 2022, the

Fern Hollow Bridge The Fern Hollow Bridge is a bridge in the East End (Pittsburgh), East End of Pittsburgh, Pennsylvania, United States, that carries Forbes Avenue over a large ravine in Frick Park. The current bridge is the third on the site. The first Fern Hollo ...

across

Frick Park Frick Park is the largest municipal park in Pittsburgh, Pennsylvania, United States, covering . It is one of Pittsburgh's four historic large parks. History The park began when the industrialist Henry Clay Frick, upon his death in 1919, bequeat ...

collapsed, forcing the closure of

Forbes Avenue Forbes Avenue is one of the longest streets in Pittsburgh, Pennsylvania, United States. It runs along an east–west route for a length of approximately . History According to historical writer and blogger Leon J. Pollom, the lowest section of ...

through the park. The bridge was covered with snow when it collapsed at 6:39 a.m. local time as it was being crossed by several cars and a bus. The bridge was rebuilt and reopened on December 22, 2022.

Major bridges

This table lists all bridges crossing the Allegheny, Monongahela and

Ohio Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...

rivers in the City of Pittsburgh limits. Other large or notable bridges are also included.

Monongahela River The Monongahela River ( , ), sometimes referred to locally as the Mon (), is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed August 15, 2011 river on the Allegheny Plateau in nor ...

Allegheny River The Allegheny River ( ; ; ) is a tributary of the Ohio River that is located in western Pennsylvania and New York (state), New York in the United States. It runs from its headwaters just below the middle of Pennsylvania's northern border, nor ...

Ohio River The Ohio River () is a river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing in a southwesterly direction from Pittsburgh, Pennsylvania, to its river mouth, mouth on the Mississippi Riv ...

Other bridges

This table lists some other major bridges within the City of Pittsburgh limits.

References

External links

Bridges & Tunnels of Allegheny County and Pittsburgh, PAAllegheny County entry at Historic Bridges
* {{DEFAULTSORT:Pittsburgh Bridges Bridges in Pennsylvania Pittsburgh-related lists