CRANBERRY TWP — Most roads that were closed or otherwise at an impasse after Tuesday's squalls were collector roads — which connect major arteries and local roads — maintained by PennDOT.

The rate at which snow fell Tuesday left PennDOT realizing its road crews couldn't maintain good conditions on every road.

“It was a fluke in a sense that we had 2 inches fall in under an hour,” said Jamie Arehart, a PennDOT spokeswoman. “When a whiteout like that happens, we cannot be literally everywhere at one time.”

Temperatures plunged from around 30 at noon to just over 20 degrees by rush hour, according to the National Weather Service. At lower temperatures, rock salt becomes less effective.

Cranberry is home to approximately 150 miles of public roadways, with the state responsible for about 20 miles. State-maintained roads in the township include Interstate 79, Routes 19 and 228, Franklin Road and Glen Eden Road.

The last two — Franklin and Glen Eden roads — were closed in part after 4 p.m., according to township police Sgt. Chuck Mascellino. They are also considered collector roads, sending motorists from local roads to the arteries of Routes 19 and 228.

PennDOT operates 42 routes over 1,600 miles of roads in Butler County, according to county PennDOT manager Mike Mattis. In an average snow event, he said, it takes a truck between two to three hours to clear the roads. Out of necessity, he said, the routes took more time.

“If we're getting that much snow, our main priority is the main roads,” Mattis said. “We're going to get to every road, but with that much snow, we try to focus on our mains.”

While road closures extended many drivers' commutes, there were only four accidents in the township between 3:35 p.m. and 5:15 p.m., according to Mascellino. He did not know if there were injuries in those collisions.