Parkway East construction today was held up briefly when a motorist drove past a barricade at an onramp, zigzagged around missing patches of concrete and finally smashed into a foot-deep gap in the road as astonished work crews stood by.

"When they hit that hole up there I heard the bang and a couple of construction workers yelled," said John Sallade, a flagman who was standing below the area near the Edgewood-Swissvale interchange when the incident occurred around 9 a.m.

The car, driven by Andrew Stahl, picked up enough speed to actually clear the hole, the front tires smashing into the far edge and landing the car on the other side.

"They actually made it to the other side. They had to be going a good speed to do that," said Mr. Sallade.

Both Mr. Stahl and his passenger, Joseph Duffy, were taken away by ambulance to UPMC Presbyterian. Mr. Stahl suffered moderate injuries, according to state police, while Mr. Duffy's injuries were minor.

PennDOT spokesman Jim Struzzi said the car entered the highway on a closed on-ramp from Monongahela Avenue.

According to a construction inspector at the scene, the Mr. Stahl said he didn't think the warning signs applied to that section of the road.

"He actually drove up the closed ramp where the concrete was removed, he drove around the barricade," Mr. Struzzi said.

"He got up on the Parkway somehow and continued to drive through the work zone. Actually drove around our contractor's workers, driving on the shoulder, and then he got onto the parkway again into the driving lanes and was weaving in and out of the patched areas until he hit the one that he did."

The site was being worked by Golden Triangle Construction Co., which specializes in rapid concrete replacement. The crews, regarded as one of the most skilled in the road construction business, lay sections of highway with concrete that sets within 14 hours, in time for the road to reopen Monday.

"I think they were pretty much in shock," Mr. Struzzi said of the workers. "They're lucky it wasn't worse."