According to Allcitycodes, the Mid-County Expressway, also called Blue Route, is part of Interstate 476 in Pennsylvania. The highway forms the western bypass of Philadelphia, from I-95 at Chester to the Pennsylvania Turnpike at Plymouth Meeting. The highway is toll-free and 32 kilometers long.
In the port city of Chester, the Mid-County Expressway begins at a major interchange with Interstate 95, the highway from Wilmington to Philadelphia. The highway then runs 2×2 lanes north through the sparsely built suburbs west of Philadelphia. The area is heavily wooded and does not give an urban feel. At the suburb of Media, one intersects with US 1, a short highway that begins here and runs west, through the further western suburbs toward Baltimore. To the east, the road leads to the northern boroughs of Philadelphia. From the junction at Broomall, the highway has 2×3 lanes. Despite the many suburbs, this area has few exits. The highway curves northeast after it connects with US 30, and intersects at Consohocken with the Schuylkill Expressway, part of Interstate 76 in Pennsylvania, the highway from Pittsburgh and Harrisburg to Philadelphia. The highway crosses the Schuylkill River here in an industrial area and the toll plaza follows at Plymouth Meeting. This is where the Mid-County Expressway ends at the intersection with the Pennsylvania Turnpike, deInterstate 276, which carries east-west traffic north of Philadelphia toward New York City. Straight ahead, Interstate 476 goes to Allentown and Scranton as a toll road.
The Mid-County Expressway would prove to be one of the most controversial highways in the Philadelphia area. As early as 1929, a bypass through the west of the Philadelphia region was included in the road plans. The plans were also included in a plan for a regional network of parkways in 1932, but little got off the ground. The planning was taken over by the Pennsylvania Turnpike Commission after World War II as a toll road, a tributary of the Pennsylvania Turnpike. In 1955 the route was included in the plan of the Interstate Highways. In 1958 the elaboration of the plan started, with three route alternatives, eventually the so-called ‘Blue Route’ was chosen, which would cost $ 40 million and should be ready in 1964. Opposition delayed implementation and led to a modified design that would cost $78 million.
Construction began in 1967 and two segments with 2×3 lanes were completed in 1970 and 1974, but not open to traffic. The section, completed in 1970, was 4 kilometers long between Broomall and Bryn Mawr, but had no connections to other roads, it lay unused in suburban areas. The section, completed in 1974, was 3 kilometers long and was located near Radnor. This connected to the interchange with I-76 at Consohocken, but was not opened yet because there was no connection at the southern end. Finally, in 1979 the first section was opened to traffic, a 4.5 kilometer long bypass of Consohocken, from I-76 to Germantown Pike.
There was a struggle for years about the route and in the end a very sober design was chosen with 2×2 lanes and fewer connections, in contrast to the first parts that were constructed with 2×3 lanes. Construction did not finally resume until 1985. In 1987, the southernmost 1-kilometer stretch opened between the interchange with I-95 and nearby McDade Boulevard. The remainder of the route between I-95 and I-76 was subsequently constructed and opened in its entirety on December 19, 1991. A year later, on December 16, 1992, the northern section opened, which was essentially the interchange and toll plaza with I-276. This completed the motorway after 64 years of planning
I-476’s narrow profile quickly proved to be a problem, with significant congestion within a few years of opening, as the highway was originally planned for 2×3 lanes in the 1960s and actually required 2×4 lanes by 2000.
With more than 100,000 vehicles on the 2×2 portions, the Mid-County Expressway ranks as one of the most congested highways in the Philadelphia area.