Fare-paying passengers have travelled for the first time on one of the new generation of tilting trains.
Sir Richard Branson with his new tilting train
The Virgin Super Voyager going between Reading and Manchester briefly tilted at 110mph between Oxford and Banbury.
The 15-mile stretch of track is the only one suitable for trains to tilt outside of the West Coast Main Line.
Virgin boss Sir Richard Branson joined passengers on the tilting service as it embarked on its maiden journey on Thursday morning.
Tilting trains are able to go round bends faster than conventional rolling stock and can therefore reduce journey times.
Until Thursday, the only tilting train to carry passengers was the British-built Advanced Passenger Train (APT-P), a prototype which ran between Euston and Glasgow from 1982-1983.
But the APT-P was dogged by passenger travel sickness and the project lost government support.
The 110mph tilt operation on Thursday heralds plans for Virgin's Italian-built Pendolino trains to tilt at 125mph on the West Coast Main Line from autumn.
There are currently 200 miles of track on that line suitable for tilting trains.
The stretch between Oxford and Banbury is expected to remain the only suitable one outside of the West Coast Main Line for tilting for the foreseeable future, Virgin bosses said.
Mark Sallis, 34, travelling from Reading to Birmingham, described the
experience as "smooth".
But he said he was not sure that tilting trains would attract more customers.
He said: "I think it's more fundamental than that. I think it's just having a more reliable and safe service.
"But for me, the less time I spend on the train, the better."
Sir Richard, who handed out certificates commemorating the event to
passengers, acknowledged that there had been problems in the past.
He said: "We have been hamstrung by Railtrack in the past.
"Network Rail are working extremely hard and they are delivering what we need
to do the job.
"It has been frustrating but they are catching up with the enormous amounts
of money being invested."
Sir Richard denied that ticket prices would have to rise to pay for the new
trains, saying that the new stock could accommodate more passengers and
therefore bring in more money.