UK rail passengers lost an estimated 3.9m hours to delays in 2018, according to consumer group Which?
The data covers trains which arrived at their destination 30 minutes or more late, and is based on 8.1m such journeys in the year.
About 80 trains a day fitted this “significantly” late definition.
The Rail Delivery Group, which represents operators, said “rail companies are working together to improve punctuality”.
Another 660 trains per day were cancelled.
It was the highest figure for cancellations since comparable records began in 2011, according to Which?, which used Office of Rail and Road data to compile its results.
Passenger groups are keen to avoid last year’s chaos, when thousands of trains were cancelled amid a change of timetables.
Weather, strikes and signalling failures last year also brought down train reliability.
“Passengers have faced a torrid time on the trains since the beginning of last year where the rail industry has fundamentally failed on punctuality and reliability,” the group’s head of campaigns Neena Bhati said.
“People then face a messy and complex compensation system which puts them off claiming when things go wrong.”
Which? said that 36% of passengers do not claim delay compensations they are owed, and suggested that the payments should be automatic.
“We know that services on some routes weren’t good enough last year and rail companies are working together to improve punctuality and tackle delays across the country,” said Robert Nisbet, regional director of industry body the Rail Delivery Group.
“Train companies want to make it simple and easy for customers to claim compensation if they’ve experienced a delay.”
“Half of the franchises managed by the Department for Transport pay compensation after 15 minutes and some operators have introduced automatic refunds, helping claims to increase by 80% over the last two years.”
A review of the rail industry was commissioned last year, following criticism of the way the franchising model is run.
It is being led by former chief executive of British Airways, Keith Williams, who said it will consider all options, including renationalisation.
A Department for Transport spokesman said the Rail Review is “focused on reforms to put passengers at the heart of the railway and will consider all submissions closely”,
Passenger satisfaction with rail services fell to a 10-year low, according to a report published in January by the independent transport watchdog, Transport Focus.
A survey of 25,000 people found 79% were satisfied overall with services, the lowest since 2008, with more than one in five passengers not satisfied.