Amtrak disruptions are on the rise in the Northeast and are likely to linger for years as extreme weather events become more frequent, Amtrak's aging fleet requires more upkeep and reconstruction projects begin on the nation's busiest passenger rail corridor, railroad officials say.

Delays have plagued travelers from D.C. to Boston in recent months, many attributed to heat-related speed restrictions and train breakdowns. Track work has also hampered trips up and down the route.

"This is really part of the conundrum we face," Amtrak president Roger Harris said, citing decades of deferred maintenance on the 457-mile route, part of it dating back 190 years. "Now we have the money to do work. And to do work, you have to do things like take tracks out of service to get the work done."

The carrier, which transports more passengers in the Northeast than airlines, is launching major construction projects along various segments of the route as it begins to use some of the $66 billion made available for rail in the infrastructure law. Most of the money, federal transportation officials say, will go toward upgrading track and replacing century-old tunnels and bridges along Amtrak's Northeast Corridor.

As work moves forward, train operations will be affected as the company considers overnight track shutdowns to speed the repairs. Among the ongoing work is a major overhaul of the 1950s-era catenary system that carries electric power to trains, as well as improved draining and track upgrades to replace aging wooden ties.

Massive projects, such as the construction of a new Hudson River tunnel between New York and New Jersey and a replacement for the 150-year-old Baltimore and Potomac Tunnel, have received federal funding and will require years of construction.

Before those projects begin, service disruptions already are prevalent this summer in the New York area, where single-tracking and work zones around Penn Station have slowed trains up and down the corridor.

On Wednesday, train delays varied from 20 minutes to more than an hour across different sections of the Northeast Corridor. A trespasser south of Boston delayed an Acela train by an hour. A Northeast Regional train departed Washington 40 minutes late because of mechanical issues. A crew change problem delayed departure of a Washington-bound Northeast Regional train in Richmond.

Systemwide, more than one-quarter of Amtrak passengers encountered delays in June, according to performance data, with an average delay of 54 minutes. Disruptions are more pronounced for travelers on long-distance routes — which are late more than half the time — and in parts of the country outside the Northeast Corridor. The share of delayed customers is also trending up, Amtrak's data shows.

In the Northeast, 22 percent of trips encountered delays in June, with those on Northeast Regional trains experiencing the most problems, data shows. That was a decline in timeliness compared to June 2019, when 15 percent of trains were late.

Delays also have stemmed from a July derailment in Washington, collisions at rail crossings and trespassers entering restricted areas along the track. The work — combined with weather-related speed restrictions — have meant longer trips for passengers.

"They've got all sorts of excuses. Bottom line is, it's not just bad, it's unacceptable," said Sinan Ciddi, an Alexandria resident who takes a Northeast Regional train most weeks to Quantico, where he teaches security studies.

Rarely is his train on time, said Ciddi, who has experienced delays of 15 minutes to more than an hour this summer. On a recent morning, he said, his train was delayed 90 minutes because of a signal problem at Union Station. When he travels to New York, he flies because of concerns over the rail network's reliability.

Amtrak said its fleet, which includes trains about 50 years old, is requiring more frequent maintenance. Amtrak purchased new trains for the Northeast, including 28 Acela trains that were planned to enter service in 2021, but now are in line to debut next year. The company decommissioned four Acela trains during the pandemic because they were past their life span.

The rising challenges come as demand for Amtrak service has surpassed 2019 numbers, while the carrier has said it's constrained to increase capacity because it doesn't have enough trains. Amtrak served more than 1.1 million Northeast Corridor passengers in June, up slightly from June 2019.

Sean Jeans-Gail, vice president of government affairs and policy at the Rail Passengers Association, said it's a terrible time to have more service breakdowns, considering the surge in ridership and that new passengers - many of whom are younger and travel for leisure - are experiencing rail for the first time. Passengers are reporting frustration across the network, he said, and in the Northeast in particular, raising questions about effects from maintenance work.

"Yes, it's going to get worse," he said. "We are in for more significant disruptions to the way we move around the country."

During the summer months, Amtrak is issuing daily alerts to passengers that trains might experience delays because of excessive heat and weather-related disruptions. Officials say rail congestion and speed restrictions can reverberate across the entire system.

Advocates are pressing Amtrak to take steps that could reduce the delays, while passengers say the railroad isn't communicating the problems effectively.

On a recent business trip to New York, D.C. resident Brian Gray's train was delayed an hour at Union Station. He said he never received a notification indicating a late departure time.

"The only way to know of a delay was to keep an eye on the display boards," he said. "There was no mobile app notification, text message or email sent about the delay. And you had a crowd of people gathering, all equally confused and frustrated."

Amtrak said it is working to improve communications and has taken steps to compensate the rising number of passengers who experience problems. Passengers can use a self-serve process for ticket refunds when a train is canceled or to change trains when they are delayed.

Jeans-Gail said he is looking on the bright side: The investments should reduce problems in the long run.

"There will be a return on investment, but there's no relief in the short-term," he said. "This is a problem 50 years in the making and we're not going to wave a wand and fix it overnight."