FRANKLIN TWP — Two children and a man were flown Thursday morning by medical helicopters to hospitals following an accident on Route 422.

State police at the scene said a NOGA Ambulance van was taking John Hunter, 72, to VA Butler Healthcare when it was hit in the rear by a van driven by Rowdy Williams, 24.

Williams was driving with his two sons, ages 6 and 8.

The ambulance with NOGA Ambulance, which offers non-emergency transport service, was stopped in eastbound traffic that was backed up due to a construction zone up the road.

The 9 a.m. accident occurred just before the intersection with Route 528.

Unionville and Portersville volunteer fire departments assisted at the scene.

Unionville Fire Chief Greg Brewster said the children were conscious and flown to the Children's Hospital of Pittsburgh of UPMC.

Brewster said Hunter was flown to another Pittsburgh hospital.

Williams was taken to Butler Memorial Hospital with injuries.

Travis Jones, 29, the driver of the NOGA ambulance, and an aide, Christine Kroner, 42, were taken to Jameson Hospital in New Castle with minor injuries.

The addresses of those involved are not known.

Brewster said Williams, who was driving a R. Williams Paving of Pittsburgh company van, failed to slow down for stopped traffic and struck the NOGA Ambulance, causing it to flip onto its side.

State police said Williams struck the ambulance at a high rate of speed, pushing it 75 feet.

Williams' van traveled 85 feet before coming to a stop against the guardrail on the opposite side of the eastbound lanes.

The accident backed up traffic in both directions on Route 422 for more than an hour because a section of the road was closed for the helicopters to land.

It reopened by 11 a.m.

The state Department of Transportation will be altering the traffic patterns in the construction zone, which spans east of the Route 528 interchange through the Eagle Mill Run Road intersection.

Debra Casadei, a spokesman for PennDOT, said traffic will stay open in both directions while crews work on the three-lane road.

The change is based on previously monitored traffic patterns.

While the additional lane of traffic is expected to ease congestion, Casadei said it still is important for drivers to slow down through the zone.

“Drivers need to be prepared and expect the unexpected,” she said. “They need to stay alert and pay attention.”

Casadei said there will continue to be a lot of roadwork the rest of summer.

“It's very important that drivers slow down while traveling through work zones,” she said. “You should start to slow down at the first sign.”

The Route 422 paving project is expected to continue until late August.