A passenger on the Severn Beach train line through Bristol says the service is so bad they're often left stranded.
Ashley Bridle told ITV News the vast majority of services he relies on end up delayed or even cancelled.
Mr Bridle kept a week-long video journal documenting his experiences using the Severn Beach line.
He says some services were running 20 minutes late which affected later trains. He also says a service to Avonmouth was cancelled entirely.
Mr Bridle is looking for a job and relies on the train to get to the job centre. He says even a small delay can cause problems.
"I'm due to sign on at 12:20 and the train is arriving over 10 minutes late. Being late to sign on, I can only hope that they're sympathetic and do not sanction my money."
The line runs from Bristol Temple Meads to Severn Beach, stopping at small stations along the way.
Some passengers claim that if the service is running late it will terminate at Avonmouth, forcing them to make their own way to Severn Beach.
Services along the line were upgraded earlier this month with the introduction of new turbo trains.
But Mr Bridle says services are less reliable since the changes.
"It's literally just made it a lot worse. We've been complaining for years because of late services and cancellations. For a couple of years it did get better but this is literally the worst we've ever seen it. It's never been this bad."
GWR said in a statement they attribute the delays to the new system but are expecting services on the line to improve soon.
"We're sorry some customers have experienced delays on Severn Beach lines as we replace older trains with a more modern fleet. Although the improved reliability, performance and comfort of the trains themselves has been clear, changes to the way trains operate on the line have caused some initial problems. We are already seeing this improve, and expect to see a return to the usual high performance on the line very soon."