Anger among commuters trapped on a train crowded with U2 fans, rather than random idiocy, is being blamed for disrupted rail services to the first of the Irish band's two Mt Smart concerts.

One regular train passenger, who would not be named, contacted the Herald to challenge a suggestion by rail operator Veolia Transport that delays in getting the fans to the Thursday night concert were the fault of one "idiot" who kept pushing an emergency stop button.

Up to four other trains were left standing near Ellerslie station for 20 minutes as a result, nearly causing thousands of fans to miss U2's opening numbers.

About 8500 fans took trains to the concert, and 9500 rode back to Britomart afterwards, taking advantage of a free travel offer.

The commuter said he was among four people who left his train at Ellerslie after one of them pushed the emergency button in frustration that it was not stopping at stations along the way, despite assurances from Veolia staff to himself and others that it would.

He said train crew first ran into difficulties at Newmarket, where doors jammed while they tried to stop more passengers from boarding overcrowded carriages.

The train stopped short of the next station, Remuera, where the platform was also crowded with concert-goers, and a commuter in his carriage was prevented from getting off there.

When the train reached his destination, Green Lane, he said it passed through without stopping and as it approached Ellerslie a man worried about being late for work threatened to push the emergency button to ensure he could get off there.

He did not know who eventually pushed the button but said that when the train stopped, he and three others took the opportunity to get off there and he had to take a taxi home, for which he was seeking a refund from Veolia.

"What we have to do is educate Veolia that this is unacceptable for New Zealand portraying itself in the [Rugby] World Cup next year if this is going to go on." he said. "This is going to happen, people who get pissed going off to rugby matches, they're going to pull cords if they get frustrated."

He said the company could have easily prevented crowd control problems at Newmarket if it had communicated clearer messages to concert-goers that they should wait another 10 minutes for the next train.

Veolia service delivery general manage Steve Wade said trains going to Penrose to drop off U2 fans were timetabled to stop at all stations along the way, and drivers deviating from that arrangement should have sought permission first.

He said he was at the Britomart control centre at the time, and heard no requests for permission to run past any stations, but he said the company would investigate any complaints.

He had rostered more crew and security staff for Friday night's concert to ensure nobody pushed an emergency button for non-urgent purposes.