The hearing came a day after Amtrak announced a multistep plan to address some of the problems at Penn, through which 600,000 customers travel each day - almost half of them on the Long Island Rail Road.
Moorman's testimony came a day after NJ Transit Executive Director Steve Santoro told another legislative committee that while he also expects delays, the reopening of Hoboken Station should mitigate some of the backup.
Lawmakers said they have been hearing horror stories from stranded and delayed commuters in recent weeks due to service interruptions in the Penn Station area, which has a ripple effect that backs up trains along the northeast corridor.
Republican New Jersey Gov. Chris Christie had promised to halt state payments to Amtrak after the derailment but said Thursday after an unrelated address to a business group that the new efforts satisfied him.
"The events of the past month have shown that we just have to step up our game there", he said.
But transportation guru Martin Robins said Amtrak should never have allowed the station and tracks to deteriorate this badly, for so long, in the first place.
Moorman said the work will continue "throughout the summer and beyond" to compete improvements originally scheduled to stretch over years.
"It is our goal to cause the least amount of disruption in the station that we can".
Amtrak officials testify at a joint legislative hearing
The agency's aging infrastructure has faced scrutiny following the derailments, which Moorman said spurred the agency to accelerate the work it plans to do this summer.
Both Amtrak and New Jersey Transit have future plans to expand service in and out of Penn Station. NY and New Jersey have offered to pay half the cost if the federal government pays for the rest, a proposal now being considered by the Trump administration. When asked if they didn't see this coming, he said, "Somebody could have".
Commuters who already have endured recent slowdowns at New York's Penn Station are about to hear about more potential delays.
"The good news is that Amtrak is taking seriously the issue of the infrastructure in and around Penn Station".
'It was clear to me that we needed to do a deep dive and look at the instructions we were providing our crews, Robert Lavell, vice-president and general manager of rail operations, wrote in a September 21, 2016, letter to Janet Lee, a deputy regional administrator for the federal railroad agency.
"These delays and cancellations affect people's lives", said Assemblywoman Elizabeth Maher Muoio.
FILE - In this Monday, April 3, 2017, file photo, police and fire vehicles respond to news of a train derailment at Penn Station, in NY. New staff is also being added to boost track maintenance and other rail services, he said.
Funding for Gateway, considered one of the most important infrastructure projects in the country, now hangs in the balance as the White House considers a budget proposal that would strip money from one of its major contributors. If the [track outages] are on the north side of the station, that's a different answer.
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Indian Foreign Secretary S Jaishankar had also met High Commissioner of Pakistan to India Abdul Basit on Tuesday and raised similar points.