[3][4] PA 50 enters South Fayette Township in Allegheny County and becomes an unnamed road, heading through wooded areas with some nearby residential and commercial development.

The route winds northeast near more suburban areas separated by woodland, with the Wheeling and Lake Erie Railway a short distance to the northwest of the road.

Past this interchange, the route turns north-northeast onto four-lane undivided Washington Avenue and crosses the Chartiers Creek into the borough of Bridgeville.

PA 50 passes more homes and businesses, with the Orange Belt turning west at Prestley Road, prior to crossing the Chartiers Creek into Collier Township and heading northeast past several commercial establishments on four-lane divided Washington Pike.

The route becomes a four-lane undivided road and runs past more businesses with some homes, passing through Kirwan Heights and coming to a ramp that provides access to I-79 to the west.

The road continues north-northeast through areas of residential and commercial development between I-79 to the west and the Chartiers Creek to the east, entering Scott Township and passing more businesses as a divided highway.

[3][5] The route becomes divided again crosses the Chartiers Creek back into Scott Township, becoming Washington Avenue and turning northeast as it passes over the Pittsburgh and Ohio Central Railroad at the Carothers Avenue/Hope Hollow Road intersection.

At this point, the Yellow Belt turns southwest onto that road while PA 50 heads northeast onto East Main Street, passing downtown businesses before running past a mix of residential and commercial development.

The route comes to an interchange with I-376/US 22/US 30 with access through local streets as it crosses back into Scott Township and heads east through more suburban development on Noblestown Road.

The road turns northeast and becomes the border between the city of Pittsburgh to the northwest and the borough of Green Tree to the southeast as it passes through wooded areas with some nearby homes.