NEWARK, N.J. – A 90-minute power outage at Newark Liberty International Airport messed with airlines' schedules and left them struggling to get back to normal late Monday afternoon.

Residual delays were expected into the evening as a result of the outage, which also affected 20,000 customers in neighboring towns. The Federal Aviation Administration was reporting one-hour arrival delays, and the monorail that moves among the airport's three terminals was not working shortly after 5 p.m., about an hour after power was restored.

Flights were allowed to land during the outage, but security checkpoints had to close, said Ron Marsico, a spokesman for the Port Authority of New York and New Jersey, which operates the airport.

"It was a little disorienting, but it wasn't that bad," said passenger Sy Carruthers, of Dorset, England, who was waiting for a flight to Iceland. "It's just one of those things."

It was also much better than the last time he flew to the United States. That was Dec. 27, when he said a storm kept his plane on the tarmac at John F. Kennedy International Airport in New York City for 10 hours.

Traffic on roads leading to the airport and on airport grounds was snarled Monday evening because traffic lights had been knocked out. They were gradually being reset and turned back on.

Work crews were in the process of upgrading a Public Service Electric and Gas switching station in Elizabeth at 2:30 p.m. when an electrical failure knocked out power to customers in Hillside, Elizabeth, Union, Newark, Roselle, Linden, Kenilworth and Irvington, as well as the airport, said Bonnie Sheppard, a PSE&G spokeswoman. Power was restored around 4 p.m., she said.