The number was assigned based on the function the route serves as a southeastern extension of I-283, but I-283 and PA 283 are not the same roadway; the two intersect at a partial cloverleaf interchange.

The route comes to a bridge over the Middletown and Hummelstown Railroad and the Swatara Creek, at which point it enters Londonderry Township.

Past this interchange, the freeway curves south-southeast through wooded areas with some fields and homes, passing over I-76 (Pennsylvania Turnpike).

The route heads through farm fields with some homes and commercial development, coming to a diamond interchange with Cloverleaf Road that serves the community of Rheems to the south.

PA 283 continues through agricultural areas with some development and curves east, crossing Little Chiques Creek into Rapho Township.

PA 283 crosses Chiques Creek into East Hempfield Township and comes to a diamond interchange with Spooky Nook Road that serves the community of Salunga to the south.

Along this stretch, the road is separated from the developed area to the south by woods and Amtrak's Keystone Corridor railroad line.

The route passes over Norfolk Southern's Lititz Secondary railroad line before it comes to an interchange with PA 741, at which point it crosses Little Conestoga Creek into Manheim Township.

Past here, the freeway widens to six lanes and runs through industrial areas, coming to a partial cloverleaf interchange with PA 72.

After crossing into the city of Lancaster, PA 283 reaches its eastern terminus at an interchange with the US 30 freeway, which also provides access to Fruitville Pike.

Construction began in 1951, concluding the following year, to extend the expressway past the current eastern terminus of PA 283 at US 30 to US 222 (Oregon Pike).