Saw Mill Run Boulevard - State Route 51
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Saw Mill Run Boulevard runs along the Saw Mill Run Corridor, following the path of Saw Mill Run Creek. It begins at the intersection of Clairton Road and Stewart Avenue on the City of Pittsburgh boundary with Brentwood.
The roadway runs north through Overbrook and forms the eastern border of Brookline. It passes the Liberty Tunnel/West Liberty Avenue and the Fort Pitt Tunnel/Parkway West interchanges. It ends at the West End Circle near the entrance to the West End Bridge.
A four-lane road its entire length, the northernmost section, known as the West End Bypass, is designated an expressway. The Bypass runs from the Parkway West interchange to the West End Circle. The entire roadway is part of State Route 51 and US Route 19.
Saw Mill Run At The Turn-Of-The-Century
In the early 1900s Saw Mill Run was no more than a dirt path leading south along Saw Mill Run Creek from the intersection of West Liberty Avenue and Warrington Avenue. The township road, called the Warrington Avenue extension or Kaiser Avenue, ran to a point near Edgebrook Avenue. When World War I began, the name Kaiser Avenue was replaced with Saw Mill Run Road
At Edgebrook Avenue began a patchwork of residential streets in the old town of Reflectorville. After passing through the village to Nobles Lane, the Library Road Extension carried travelers through to the town of Fairhaven and the Library Road intersection.
Rapid Development Of The South Hills
As development of Pittsburgh's southern neighborhoods and nearby suburbs began in earnest, the need for a better roadway became a necessity. With the construction of the Liberty Tunnels underway in 1920, the transformation of Saw Mill Run began.
The project would take another ten years to complete, but by 1930 there would be a four-lane highway stretching from the Banksville Traffic Circle all the way through to Library Road in Overbrook. Further road construction in the 1950s took the boulevard from Banksville Road to the West End.
"City Beautiful" Bond Issue - 1928
Saw Mill Run Boulevard was created as part of the 1928 Allegheny County "City Beautiful" bond issue. The bonds resulted in the creation of Saw Mill Run, Ohio River, Allegheny River and Mosside Boulevards. After the completion of the Liberty Tunnels in 1924, the city of Pittsburgh became easily accessible to the South Hills area.
As the southern communities grew, county and city planners looked for a roadway that would connect eight important throughway and improved roads (Library Road, Nobles Lane, West Liberty Avenue, Banksville Road, Washington Pike, Noblestown Road, Steubenville Pike and Carson Street.) It was also viewed as a way to bring the cities of McKeesport, Clairton and Duquesne closer to Pittsburgh.
Construction - The Library Road Extension - 1929/1930
Construction began quickly. The first phase of construction would be the improvement of the Library Road Extension, which ran from Provost Road to Warrington Avenue. Modern sewers were laid near the West Liberty Avenue intersection back in 1925. Other infrastructure improvements would construction challenges would prove more difficult.
The road network at the Whited Street (Oak Street) intersection required a complete reconfiguration and reconstruction, as there was no actual through road at this point, just a merging of several different streets.
Another engineering difficulty was the intersection at Library Road. A heavily traveled interchange in the heart of Overbrook Borough, five roads all converged on that location.
Library Road, Ivyglen Street, Hillview Avenue, Stewart Avenue and Glenbury Street all had to be merged with Saw Mill Run Boulevard. In addition to the multiple roadways, the design was complicated by the presence of Saw Mill Run Creek and tributaries that criss-crossed the terrain. The resulting interchange consisted of a concealed system of five bridges with tunnels to channel the water.
After Library Road, other intersections included Maytide Street, Nobles Lane, Whited Street, Edgebrook Avenue, Bausman Street, West Liberty Avenue and the Liberty Tunnels. The first phase of construction was completed on December 1, 1929. A special dedication and parade was held in the Spring of 1930.
During the next phase of construction, the boulevard was extended from Warrington Avenue to the Banksville Traffic Circle, with exits onto Banksville Road and Woodville Avenue. This second stretch of roadway, with intersections at Crane Avenue and Woodruff Street, opened in September of 1930.
* Thanks to Tim Killmeyer for many of the Phase One and Phase Two images *
Construction - The West End Bypass - 1949/1951
Originally proposed in 1939 by famed planner, Robert Moses, as part of the "Moses Plan", construction on the Saw Mill Run Extension, better known as the West End Bypass, began in 1949. The 1.1 mile expressway began at the Banksville Traffic Circle and ran to the West End Bridge.
The extension was completed in 1951. The Banksville Traffic Circle was eliminated during the construction of the Parkway West (US279) in the mid-1950s. The loop was replaced with a modern interchange that connected Saw Mill Run Blvd, the West End Bypass, Banksville Road, Woodville Avenue, the soon-to-be-completed Fort Pitt Tunnels and the Parkway.
Further Improvements - 1990/present
After sixty years of service, Saw Mill Run Boulevard began to see improvements made during the 1990s and 2000s. In the early 1990s median barriers were installed from Whited Street north to the Parkway West interchange. In 1998 work began on a new traffic design where Saw Mill Run meets West Liberty Avenue and the Liberty Tunnels.
The heavily-traveled interchange, which handles over 100,000 vehicles per day, had been a bottleneck for years. Plans were in place in 1957 for a design change, but they were never put into action. Finally, in 1999, the new interchange was completed and has been hailed as a major improvement.
Construction of a new traffic design pattern at the equally-crowded Northern Terminus of Saw Mill Run Boulevard, approaching Carson Street and the West End Bridge, began in the mid-2000s. An additional lane was added to the highway and the hillside was stabilized.
The intersection at the West End Circle was redesigned, with the construction of a third tunnel to allow a more coordinated traffic flow. The project was completed in 2010. The new interchange was welcomed by motorists as a major improvement.
Finally, near the southern edge of the Boulevard, a complete rehabilitation of the overcrowded Library Road (State Route 88) intersection is planned for the near future. Initial plans favored a design similar to the interchange at the Liberty Tunnels. However, After over a decade of deliberation and delays, new plans were introduced in October, 2010, favoring a jughandle design.
Beginning in late-2013 work began. Over the next several monthw, many decaying bridges along the construction path were rebuilt. Utilities and traffic signals were improved. The roadway was completely rebuilt. At a cost of over $20 million, the construction project was completed in November 2015.
Photos of Locations Along Saw Mill Run Boulevard
For more pictures Of Saw Mill Run Boulevard and the valley over the past century:
<Historical Facts> <> <Brookline History>