to the northwest and housing developments to the southeast. PA 100 splits from US 222 at a diamond interchange, at which point PA 100 continues north and Trexlertown Road heads south. US 222 continues past industrial areas and farmland, coming to a bridge over Norfolk Southern's C&F Secondary. The route bends east and runs past more farmland before heading near residential neighborhoods, crossing over Cetronia Road on a bridge before intersecting Grange Road/Mill Creek Road at-grade. US 222 crosses into Lower Macungie Township and curves to the east-northeast, passing north of a shopping center and intersecting North Krocks Road at an at-grade intersection with a northbound exit and entrance ramp for right turns and access to and from the shopping center. Past this, the route has a southbound exit to Brookside Road north of the community of Wescosville. The road comes to a bridge over the Pennsylvania Turnpike Northeast Extension (I-476) and runs between industrial development to the north and businesses to the south, reaching an intersection with Hamilton Boulevard and Cedarbrook Road/Kressler Road. Here, US 222 widens to six lanes and becomes Hamilton Boulevard again, heading east-northeast to the north of a park and ride lot before it comes to its northern terminus at a partial cloverleaf interchange with I-78/PA 309 in the community of Dorneyville. Past this interchange, Hamilton Boulevard continues as PA 222 towards the city of Allentown. History When US 222 was first designated in the 1920s, it only reached as far north as Reading, but at the time US 22 dipped down from Allentown to Reading, then west to Harrisburg. US 22 was rerouted to become a straight shot from Allentown to Harrisburg so the roadway between Reading and Allentown became part of US 222, explaining why the highway, designated as north/south, actually runs mostly east/west between the two cities. By the early 1930s the road then signed as US 22 became problematic for motorists in Lebanon along the current US 422; Reading via US 22 and US 222; and Allentown on Hamilton Street (US 22). PA 43 had been aligned as a bypass between Allentown and Harrisburg. On June 8, 1931, the American Association of State Highway Officials came to a resolution to the traffic problem, by replacing the PA 43 corridor with US 22 and the William Penn Highway name to match. The state truncated PA 43 to Susquehanna Street from Allentown to