Yesterday's test blast at the Route 28 hillside stabilization project in Harmar "went according to plan," Pennsylvania Department of Transportation spokesman Jim Struzzi said.

"It was excellent, nice and clean," he said. "The rock dumped down to the bottom of the hill like it was dumped out of a big bucket."

Both lanes of Route 28, plus Freeport Road nearby, were closed to traffic at 10 a.m. as a precaution just before the explosive charges planted in holes drilled into the hillside were detonated in a controlled sequence over a 100-foot-long section.

Mr. Struzzi said Freeport Road and the northbound lanes of divided Route 28 were reopened by 10:10 a.m. and that the southbound side was reopened a few minutes later, after dust from the blast settled and a PennDOT work crew cleaned the roadway with a mechanical sweeper.

PennDOT chose Good Friday to conduct the test because traffic volumes are lighter.

A similar, smaller test on Monday didn't go as well. Rocks and dirt tumbled down the cliff and onto part of the southbound lanes, preventing PennDOT from reopening Route 28 for more than an hour and causing a traffic jam on Freeport Road in the area south of Route 910.

PennDOT is spending $8.5 million to remove 77,000 cubic yards of rock, dirt and debris and to construct a 1,600-foot-long protective fence because of persistent slides and rock falls from the hillside that abuts the southbound lanes. PennDOT created the cliff when it carved into the hill to build the divided highway about 30 years ago.

Later this spring and over summer, PennDOT's contractor will blast sections up to 300 feet long at a time to create a shelf to catch falling rock, slightly cut back the hillside, create a larger "drop zone" along the road and remove as much of the loose shale and sandstone rocks as it can to minimize future problems.

PennDOT also has built a new southbound lane through the slide-prone area in the median, and shifted the passing lane onto it, to use the old slow lane as part of the larger new drop zone.