At the first of three scheduled public sessions to discuss the project and its effects, Hanson said a 60-day closure of the PATCO track on the south side of the bridge, starting shortly after Memorial Day, would be more disruptive than a 50-day closure on the north side later in the summer.
Both closures will mean trains will only be able to operate on a single track all day, every day.
Motorists will also be affected, as the track work will require the closure of two highway lanes on the bridge.
"If you don't have to use that bridge during rush hours, you may want to consider alternatives," Hanson said.
The project is to be finished by early 2016.
PATCO officials promised to improve communications with passengers and provide more police to control crowds on train platforms.
PATCO passengers were frustrated in January and February by a series of construction-related problems that were exacerbated by train breakdowns.
Hanson, who took over as acting general manager in January, apologized for those failures and acknowledged: "We should have planned better."
"It absolutely was not working," he said.
With revamped schedules, more employees on platforms, and more frequent announcements in stations and on social media, PATCO hopes to do better during the two extended closures, he said.
In response to questions from about a dozen people attending the Tuesday session, Hanson and other PATCO officials said the agency was in discussions with cellphone companies about providing service in PATCO tunnels.
Reopening the long-closed Franklin Square station will again be considered, Hanson said. But that would not happen until the construction project is finished and a $190 million overhaul of the PATCO fleet is completed in 2016, he said.
The first of the newly overhauled cars are now expected to be in service by early July, chief engineer Mike Venuto said Tuesday.
Two more public sessions on the construction project will be held this month:
Thursday from 5:30 to 7 p.m. at the Collingswood Community Center, 28 W. Collings Ave.
Tuesday from 5:30 to 7 p.m., at the Camden City campus of Camden County College, 601 Cooper St.