The distance between the Camp Horne Road interchange of Interstate 279 to the merge area with Interstate 79 is less than five miles, but it took Jeff Milanovich 2 1/2 hours to cover it yesterday afternoon.

"I've lived in [Washington, D.C]. for 15 years and sat in many a traffic backup, but the traffic just wasn't moving at all with the construction," said Mr. Milanovich, of Cranberry.

Two simultaneous construction projects, one on I-279 and another on I-79, caused the long delays, said Jim Struzzi, spokesman for the Pennsylvania Department of Transportation. The projects stalled traffic in both northbound and southbound lanes of both highways throughout much of the afternoon, he said, with northbound traffic on I-279 particularly sluggish.

Resulting delays left motorists fuming and furious with PennDOT as they inched along or risked collisions while making hasty U-turns to escape the jam of hundreds of vehicles.

"It's really a strange animal," Mr. Struzzi said of the afternoon. He said heavier-than-usual traffic hit the highways at the same time crews on I-79 were milling and paving between the I-279 split and Warrendale, while other workers were patching concrete on I-279 between Camp Horne Road and I-79.

The two projects, which have been under way for weeks, usually don't occur at the same time, he said. The paving on northbound I-79 was to have finished up in the morning, but took until 2 p.m. to complete. By then, crews also were working on I-279, Mr. Struzzi said. News releases were distributed and overhead signs posted in advance to warn motorists, he said.

During most of his journey, Mr. Milanovich said his car sat idling, with his two children in the back seat. Occasionally, the long line moved forward, only to halt again for long stretches. Frustrated drivers who shared the road with him looked "disgusted," he said, and many who hadn't expected the trip's duration left vehicles to relieve themselves on the side of the road.

Mr. Milanovich said he watched several near-accidents as drivers turned around in the median, wheels spinning in the mud, and headed south or sped on the shoulder past other vehicles.

"One lady hollered back that she was just about out of gas," he said.

He called his sister at home and asked her to pull up Internet traffic cameras to determine the reason for the delay.

"I thought that we going to run into a big accident, and it never happened," he said. Once he merged onto 79, the bottleneck let up and he was able to proceed home.

Other frazzled drivers who stopped at T-Bones Marketplace in Marshall told clerks there they'd spent two to three hours traveling the seven miles from the Camp Horne Road interchange of Interstate 279 to the Route 910 exit of Interstate 79. The exit, on the Franklin Park-Marshall border, offered drivers their first chance to flee the interstate north of Camp Horne Road.

The traffic congestion thinned out by nighttime.

Construction on both highways is over for the weekend, Mr. Struzzi said, but resumes tomorrow night.

Looking for more from the Post-Gazette? Join PG+, our members-only web site. You'll get exclusive sports content, opinion, financial information, discounts from retailers and restaurants, and more. Our introduction to PG+ gives you all the details.