PITTSBURGH -- PennDOT District 11 succeeded in clearing a large portion of rock from the cliffs that loom over Route 28 Saturday morning.

This took place shortly after 8 a.m. on a stretch of Route 28 south of the Route 910 Hamar interchange (Exit 11) in Harmar Township, Allegheny County.

Northbound traffic on Route 28 was stopped at the Blawnox exit and southbound traffic was stopped at the Route 910 interchange.

The road was closed for approximately 30 minutes while crews set charges and then cleared debris after the explosion.

Contractor crews removed a 210-foot section on the middle or intermediate shelf along Route 28. They have completed blasting on the upper shelf and are now progressing to the middle rock shelf.

PennDOT is investing approximately $8.5 million to remove an estimated 77,000 cubic yards of material from the hillside and construct 1,600 feet of protective rock fall fencing along southbound Route 28. The project will create a new, uniform pre-split rock face along this area historically prone for rock slides. Lane Construction is the prime contractor for the Route 28 improvement project. Kesko Inc. is the subcontractor for the blasting operations.

Rock Fall Area Tentative Schedule:

Mid March through late July: Drilling and pre-splitting

End of July through hid August: Shotcrete installation (concrete type material used to fill voids and prevent erosion)

Mid August through late September: Hauling hillside material to waste site

Late September through late December: Install drainage, barrier and rock fence and complete final roadway alignment

Motorists are advised to stay alert and watch for stop conditions on Route 28 and Freeport Road throughout the spring and summer.

The next blast is tentatively scheduled at 8 a.m. on Saturday, May 10.