The Pennsylvania Turnpike is a toll highway that is operated by the Pennsylvania Turnpike Commission (PTC) in the Commonwealth of Pennsylvania in the United States. A controlled-access highway, it runs for 360 miles (580 km) across the state, connecting the Pittsburgh, Harrisburg and Philadelphia areas. It also passes through four tunnels as it crosses the Appalachian Mountains in central Pennsylvania.
A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is enclosed except for the entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube construction techniques rather than traditional tunnel boring methods.
The Holland Tunnel is a vehicular tunnel under the Hudson River that connects Hudson Square and Lower Manhattan in New York City in the east to Jersey City, New Jersey in the west. The tunnel is operated by the Port Authority of New York and New Jersey and carries Interstate 78. The New Jersey side of the tunnel is the eastern terminus of NJ Route 139. The Holland Tunnel is one of three vehicular crossings between Manhattan and New Jersey; the two others are the Lincoln Tunnel and George Washington Bridge.
The Rotherhithe Tunnel, designated the A101, is a road tunnel under the River Thames in East London, connecting Limehouse in the London Borough of Tower Hamlets north of the river to Rotherhithe in the London Borough of Southwark south of the river. It was formally opened in 1908 by George, Prince of Wales, and Richard Robinson, Chairman of the London County Council. It is a rare example of a road tunnel where road traffic, pedestrians and cyclists all share the same tunnel bore. Transport for London took over ownership and maintenance of the tunnel in 2001.
Interstate 279 (I-279), locally referred to as Parkway North, is a north–south auxiliary Interstate Highway that lies entirely within Allegheny County, Pennsylvania. Its southern end is at I-376 at the Fort Pitt Bridge in Pittsburgh, and the north end is in Franklin Park at I-79. It primarily serves at the main access route between Pittsburgh and its northern suburbs.
Interstate 376 (I-376) is a major auxiliary route of the Interstate Highway System in the US state of Pennsylvania, located within the Allegheny Plateau. It runs from I-80 near Sharon south and east to a junction with the Pennsylvania Turnpike in Monroeville, after having crossed the Pennsylvania Turnpike at an interchange in Big Beaver. The route serves Pittsburgh and its surrounding areas and is the main access road to Pittsburgh International Airport (PIT). Portions of the route are known as the Beaver Valley Expressway, Southern Expressway, and Airport Parkway. Within Allegheny County, the route runs along the majority of the Penn-Lincoln Parkway, known locally as Parkway West and Parkway East. It is currently the ninth-longest auxiliary Interstate route in the system and second only to I-476 within Pennsylvania.
Interstate 579 (I-579) is a north–south Interstate Highway entirely within Pittsburgh, Pennsylvania. The highway is 2.73 miles (4.39 km) long. I-579 is also known as the Crosstown Boulevard since it crosses the backside of Downtown Pittsburgh.
Ole Knutsen Singstad was a Norwegian-American civil engineer best known for his work on underwater vehicular tunnels in New York City. Singstad designed the ventilation system for the Holland Tunnel, which subsequently became commonly used in other automotive tunnels, and advanced the use of the immersed tube method of underwater vehicular tunnel building, a system of constructing the tunnels with prefabricated sections.
The Caldecott Tunnel fire killed seven people in the third (then-northernmost) bore of the Caldecott Tunnel, on State Route 24 between Oakland and Orinda in the U.S. state of California, just after midnight on 7 April 1982. It is one of the few major tunnel fires involving a cargo normally considered to be highly flammable, namely gasoline.
The Fort Pitt Tunnel is a vehicular tunnel under Mount Washington in Pittsburgh, Pennsylvania. It connects the West End region on the southwest side to the South Shore neighborhood on the northeast side. The adjoining Fort Pitt Bridge on the northeast end connects to Downtown Pittsburgh. The tunnel carries traffic on Interstate 376 (I-376), U.S. Route 22, US 30, and US 19 Truck. The structure comprises two bores, each with two lanes of traffic. The inbound tunnel flows onto the top deck of the double-deck Fort Pitt Bridge, opposite traffic from the lower deck using the outbound tunnel. To accommodate the bridge, the northeast portals of the parallel tunnels are vertically staggered by 30 feet. The tunnel opened in September 1960, a year after the Fort Pitt Bridge.
Transportation in Pittsburgh, Pennsylvania is different than in many other major American cities. A large metropolitan area that is surrounded by rivers and hills, Pittsburgh has an infrastructure system that has been built out over the years to include roads, tunnels, bridges, railroads, inclines, bike paths, and stairways; however, the hills and rivers still form many barriers to transportation within the city.
The Posey and Webster Street Tubes are two parallel underwater tunnels connecting the cities of Oakland and Alameda, California, running beneath the Oakland Estuary. Both are immersed tubes, constructed by sinking precast concrete segments to a trench in the Estuary floor, then sealing them together to create a tunnel. The Posey Tube, completed in 1928, currently carries one-way (Oakland-bound) traffic under the Estuary, while the Webster Street Tube, completed in 1963, carries traffic from Oakland to Alameda.
The Liberty Tunnels are a pair of tunnels located in Pittsburgh, Pennsylvania, United States that allow motorists to travel between the South Hills of Pittsburgh and the city, beneath Mt. Washington. The tunnels were vital in the expansion of the South Hills suburbs by providing a direct route to the city, eliminating the time-consuming task of navigating around or over Mt. Washington and its inclines. Opening in 1924, the Liberty Tunnels are the longest automobile tunnel in the City of Pittsburgh.
The Mount Baker Tunnel or Mount Baker Ridge Tunnel carries Interstate 90 under the Mount Baker neighborhood of Seattle, Washington. It is actually a group of three tubes that carry eight lanes of freeway traffic, plus a separate path for bicycles and pedestrians. The original tubes are twin tunnel bores completed in 1940 and rehabilitated in 1993. The new Mount Baker Tunnel was built north of the original tunnels and opened in June 1989. The tunnel has a double-decked roadway with the bicycle/pedestrian path above the traffic lanes.
The Wabash Tunnel is a former railway tunnel and presently an automobile tunnel through Mt. Washington in the city of Pittsburgh, Pennsylvania, United States. Constructed early in the 20th century by railroad magnate George J. Gould for the Wabash Railroad, it was closed to trains and cars between 1946 and 2004.
The Yerba Buena Tunnel, also known as the Yerba Buena Island Tunnel, is a highway tunnel in San Francisco, California. It is the part of San Francisco–Oakland Bay Bridge complex that crosses Yerba Buena Island. The Yerba Buena Tunnel carries ten lanes of Interstate 80 (I-80) on two decks, connecting the two component spans of the Bay Bridge, the western suspension span and the eastern self-anchored suspension span. At the opening of the Bay Bridge in 1936, it was the world's largest-bore tunnel.
Heroes Tunnel is a 1,200-foot-long (370 m), twin-tube tunnel carrying Route 15 through West Rock Ridge in New Haven, Connecticut, opened in 1949. It is the only highway tunnel to pass beneath a natural land feature in New England, although there are other types of vehicular tunnels in the region.
The Greenfield Bridge, officially known as the Beechwood Boulevard (Greenfield) Bridge II, is a steel arch bridge located in Pittsburgh, Pennsylvania, United States. The bridge connects the neighborhoods of Greenfield and Squirrel Hill across the valley known as Four Mile Run which separates them. The bridge also spans the Parkway East (I-376), which runs along the bottom of the valley.
Tunnels are dug in types of materials varying from soft clay to hard rock. The method of tunnel construction depends on such factors as the ground conditions, the ground water conditions, the length and diameter of the tunnel drive, the depth of the tunnel, the logistics of supporting the tunnel excavation, the final use and shape of the tunnel and appropriate risk management. Tunnel construction is a subset of underground construction.
The Eyholztunnel is a 4.25 kilometre long tunnel of the Swiss highway A9, serving as a bypass of the town of Visp in the canton of Valais. The design of the tunnel began in 2005, the traffic handover took place on 13 April 2018.
I-376 / US 22 / US 30 (Parkway East)
