Pennsylvania Route 100 - History

History

PA 100 was originally signed as Pennsylvania Route 62, for its entire length. By 1940, PA 100 was commissioned although the PA 62 spurs of PA 162, PA 262, PA 562, and PA 662 still remained.

Before 2003, south of Exton, PA 100 used to continue south along Pottstown Pike towards West Chester; the connector expressway (to US 202) split from it just south of Exton. Once PA 100 entered West Chester it became High Street, the main north–south artery route through the town, and it picked up a concurrency with Business U.S. 322. Several blocks north of West Chester University it turned right onto Price Street, leaving the US 322 Business concurrency and picking up the beginning of PA 52. At the Brandywine Picnic Park in Pocopson it forked to the left onto Creek Road, leaving the PA 52 concurrency. It continued south winding through southern Chester and Delaware Counties following the Brandywine Creek into Delaware, with a very short wrong-way concurrency with U.S. 1/Baltimore Pike, then becoming Delaware Route 100. The alignment was changed due to local complaints about long-distance and freight traffic mistakenly traveling through West Chester via High Street to get to US 202 towards Delaware on the south side of West Chester, instead of the more appropriate path of travel along the spur (to US 202) which is the current southernmost part of PA 100. The old alignment of PA 100 south of Exton to the Delaware border is still driveable, although there was a slight traffic-pattern change northbound just before US 1 so that northbound traffic would have a traffic light, not a stop sign (this eliminates the northbound wrong-way concurrency with US 1 southbound).

In 2007, The Jaindl Highway (Trexlertown Bypass) opened and rerouted Route 100 onto the western loop instead of continuing on Trexlertown Road through Trexlertown.