Most Downeaster trains are still running behind schedule, and some trains between Haverhill, Massachusetts, and Boston were again canceled over the weekend, but rail authority officials say improvements are underway and the service will be returning to normal over the next few weeks.

The delays and cancellations – caused by needed repairs to tracks, rail beds and bridges – may be the worst since the summer of 2004, when a bridge failure in Kennebunk prevented Amtrak trains from making the full run between Boston and Portland and security concerns shut down the train for a week during the Democratic National Convention in Boston. The weeklong shutdown cost the Downeaster $100,000 in lost revenues.

Patricia Quinn, executive director of the Northern New England Passenger Rail Authority, which manages the service for Amtrak, said the authority hasn’t yet analyzed the impact of the delays and cancellations. Compared to this date last year, however, the service is down about 2,600 riders for the month of May, she said.

“In the last month, it’s been really tough,” she said. “We are working to get back where we used to be.”

The delays come during a year in which the Downeaster had been showing strong ridership growth. This May will be the first month since April 2013 in which the Downeaster did not set a ridership record for the month.

About 256,000 passengers rode the Downeaster in the first six months of the current fiscal year, from October through March, a 5 percent increase over the same period last fiscal year.

Two weeks ago, however, rail inspectors determined that harsh winter weather and heavy snow melt had destabilized the ground under about 27 noncontiguous miles of track, mostly between Portland and the New Hampshire border.

In addition, the Massachusetts Bay Transportation Authority this spring began to rehabilitate three railroad bridges spanning the Merrimack River in Haverhill, including a bridge the Downeaster uses to cross the river.

The MBTA work is the reason that some trains have been canceled over the last two weekends. Quinn said work on that project has been paused and won’t resume until the fall. That means no more train cancellations for the next few months.

Quinn said Pan Am Railways, which owns the tracks in Maine and New Hampshire, has been repairing tracks and strengthening the rail bed.

A week ago, many northbound trains were nearly an hour late arriving in Portland and Brunswick. The delays are now shorter, with trains for the most part arriving at their destinations 20 minutes to 30 minutes behind schedule, Quinn said.

In Portland on Monday, train No. 681 arrived in Portland at 11:59 a.m. – 19 minutes behind schedule. Disembarking passengers said they weren’t upset by the delays because they understand that tracks need to be repaired after the hard winter.

“I’d love it to be faster, but I also want it to be safe,” said Paul Prior of Boston.

Andrew Olson of Greenfield, who was picking up his son at the station, said the delays have to be put in perspective. He said the Downeaster has offered dependable transportation since the service began in 2001, so people aren’t going to be angered by delays that are occurring over a period of a few weeks. He said he also appreciates that conductors tell passengers when they board the train to expect delays.

“It doesn’t bother us one bit,” he said. “It’s a wonderful ride and a great service. It’s a great thing to have.”

Quinn said the repairs are not causing the rail authority to spend any extra money. She said the authority pays Pan Am Railways $600,000 to $700,000 annually for maintenance work, and the current work falls under that contract.

Wayne Davis, chairman of Trainriders/Northeast, the citizens group that lobbied the state to launch the Downeaster, said he’s not worried that passengers who abandoned the train for faster forms of transportation, such as Control Coach Lines, won’t come back to the train once the tracks are repaired.

“I don’t see any great threat to the service,” he said. “It’s a good service once some of the infrastructure is put back the way it should be. I think people will return to normal.”

Tom Bell can be contacted at 791-6369 or at:

[email protected]