History of The Blue Route Interstate 476 first appeared as a blue line on a map in 1955 and the highway has been called the Blue Route ever since. Fifty years ago, the blue line was one of three alignments being considered for the Mid-County Expressway that is now known as I-476. 
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Although it was scheduled to be built in 1964 at a construction cost of $40 million, I-476 was delayed for decades, largely because of environmental concerns and litigation. Two very short sections were built in 1970 (2½ miles through Radnor Township and 1½ miles through Upper Merion and Lower Merion townships), but neither section was connected to any highways or streets. It was not until 1979 that the first significant section was completed, the three miles between Exit 16 (I-76) and Exit 19 (Chemical Road). After much continued debate and great anticipation, the section from I-95 to MacDade Boulevard was opened in August 1988; the section between Chemical Road and Plymouth Road was opened in August 1991, and the stretch between MacDade Boulevard and I-76 (Schuylkill Expressway) was opened in December 1991. The total cost to design and build I-476 was $763 million. | 
