The inbound commute on Route 28, rarely a pretty thing during the ongoing construction project, has been absolutely excruciating this week.
Over last weekend, the traffic pattern changed, splitting the two inbound lanes as they approach the area of the 31st Street Bridge. The left lane descends into the dip excavated for a new interchange being built there, abreast of the single lane that is open to outbound traffic.
The result has been morning backups beyond the Highland Park Bridge and traffic flowing at 10 to 20 mph when it moves at all, according to data on the 511pa.com website. The jamming has started shortly after 7 a.m. and persisted beyond 9 a.m.
"Any major traffic shift causes dramatic impacts for a week or more," said Dan Cessna, district executive for the Pennsylvania Department of Transportation, which is overseeing the project. But he acknowledged that the delays on Route 28 are worse than hoped for.
PennDOT is evaluating the placement and activity of construction equipment to see if that can help to ease the morning mess.
"Where vehicles are staged, the width of lanes and work occurring very close to travel lanes can have an impact," he said.
Part of the problem, Mr. Cessna said, could be motorists who hesitate at the split, thinking they must choose a particular lane to get to their destination.
"Both lanes take you to the same place. We know people are struggling with these things right now. Once you get a few people slowing down, it causes the whole thing to back up," he said.
Mr. Cessna said he expects traffic conditions to improve as regular commuters become accustomed to the revised pattern.
If they don't, relief won't come until August, when the right lane rejoins the left in the man-made valley under the bridge.
The project, which is scheduled to continue into the fall of 2014, is creating grade-separated interchanges at the 31st Street Bridge and 40th Street Bridge to eliminate signals for through traffic. It also will provide permanent separation of inbound and outbound traffic, all but eliminating the risk of head-on collisions.
About 60,000 vehicles use the highway on a typical day.