New York City commuters started the work week on Monday with a slightly smoother trip thanks to the restoration of some train lines and the opening of the final road tunnel shut by flooding.
However, two major train lines from New Jersey into New York remain suspended.
Commuters were urged to use alternatives provided by NJ Transit, including free bus trips to ferries across the Hudson River.
Monday is a federal holiday - Veterans Day - which meant a less congested commute.
Some 56,000 homes and businesses on Long Island were still without electricity on Monday afternoon.
The Long Island Power Authority said it expects to restore power to most of those able to receive it by the end of Tuesday.
But up to 17,500 customers in Nassau and Suffolk and 29,000 in the Rockaways in New York City are unable to receive power safely because the flooding may have damaged electrical panels, wires, outlets and appliances.
New Jersey Governor Chris Christie said gas rationing in his state would end at 6am on Tuesday. But rationing is still in force in New York City.
At least 121 people perished in Superstorm Sandy, which caused an estimated $US50 billion in property damage and economic losses.