For the first four months of 2014, PATCO ridership was off by 6.2 percent from the same period in 2013, with just more than 3.3 million riders, down from about 3.5 million.
PATCO had enjoyed growing ridership almost every year for more than a decade, but that ended last year.
Ridership slipped slightly, to about 10.5 million passengers, from 10.6 million in 2012, the highest since 1999, according to PATCO's most recent tabulations.
The current construction also has reduced car and truck traffic on the bridge, as lane closures have caused traffic backups into Philadelphia and Camden.
Vehicle traffic was down by 4.5 percent, or 264,000 vehicles, for the first four months of 2014, compared with the same period in 2013. That resulted in $1.4 million less in toll revenue.
Thursday was Day 17 of a planned 60-day closure of the PATCO track on the south side of the bridge, as part of a two-year project to replace tracks, signals, and other components.
Ninety percent of the demolition on the track is complete, Mike Venuto, chief engineer for the Delaware River Port Authority, said Thursday.
Next is repair of steel beams, sand-blasting, and painting, before installing new concrete to support the new rails and equipment, Venuto said.
Construction is on schedule to permit the south track to be reopened in early August, he said.
Then the track on the north side of the bridge will be closed for 50 days to permit similar demolition and construction there. The entire project is slated to be finished by early 2016.
PATCO's efforts to ease overcrowding by returning refurbished train cars to service also has been pushed back again.
Now, the first eight cars reconditioned in a Hornell, N.Y., factory will not be ready for service until early August, Venuto said. That's a year behind the schedule announced in 2012.
Issues with the cars' braking performance have apparently prompted more testing.
The entire fleet of 120 PATCO cars is being refurbished, 26 cars at a time, by French train-builder Alstom Transport Inc. in a $194 million project.
In addition to the eight pilot cars now being tested at Lindenwold, four others are ready to be shipped to PATCO, Venuto said.