Squirrel Hill Tunnel is a traffic highway tunnel in Pittsburgh that opened on June 5th, 1953. The tunnel was constructed between 1946 and 1953 and cost the State of Pennsylvania Department of Transportation a reported $18 million to build. The tunnel has a controversial reputation in Pittsburgh due to the traffic bottlenecks it generates for commuters leaving the city on Interstate 376 and the numerous trailer-tractor accidents that have occurred in its existence due to its relatively short ceiling.
The Squirrel Hill Tunnel is a two-bore tunnel that carries four lanes of traffic total from Interstate 376, US-22 and US-30. The tunnel completed the last link in the first eight-mile section of the Parkway East, which was being built simultaneously.
Since its construction, the Squirrel Hill Tunnel has undergone several construction remodeling projects in an effort to improve its capabilities. The original road surface was replaced by cement concrete pavement in 1980 by the Pennsylvania Department of Transportation. The tunnel was reconfigured by city officials and Carnegie Melon students to provide commuters with cellphone service in 1987 and FM/AM radio signal in 2005. As of 2013, the city is in the process of raising the ceiling of the tunnels to better accommodate tractor trailer traffic coming into the city from Interstate 376.