File:1954 - New Lehigh Valley Thruway - 21 Sep - Whitehall Township, Lehigh County, Pennsylvania.jpg

English: New Lehigh Valley Thruway - 21 Sep - Whitehall Township, Lehigh County, Pennsylvania

The Lehigh Valley Thruway's origins begin in 1949 when the Lehigh Valley Motor Club asked the Pennsylvania State Highway Department for a Route 22 bypass. The major reason for the request was that the existing Route 22 using Tilghman Street and Union Boulevard was dangerous and not suitable for city streets to serve as a through highway. Later in 1948, a bypass plan was approved by the Federal Bureau of Public Roads, which provided federal funding for the plan.

Construction began on the Thruway in 1951 with a 4-lane limited-access highway to the north of Allentown and Bethlehem, along with the William Penn Highway between Bethlehem and Easton. Construction continued until 1954 when the section between Easton in the east and Khunsville in the west was formally dedicated on September 21st. A speed limit of 60mph was set except in Easton where the dangerous curve reduced the speed limit to 35mph. By 1959, the freeway was completed west to Foglesville and also to Lenhartsville.

With the passage of the Federal Aid Highway Act of 1956, the Route 22 bypass was designated as Interstate 78. The highway was co-designated as an Interstate highway until 1969, when I-78 was terminated to the west of Khunsville after the people of Easton successfully opposed the I-78 designation, and subsequent highway improvements. Subesquently, a proposal was presented to build a new I-78 south of Allentown, Bethlehem and Easton into New Jersey

The first major modification to the highway was in 1971 when the Airport Road intersection north of Allentown was totally rebuilt and modernized. In the years since then, various modifications to intersections and paving improvements have been performed, however the basic highway design remains the same. Various proposals for expansion have been proposed and rejected primarily due to cost.