Traffic congestion in Dublin City Centre and slow Luas speeds are partly due to a decision of the railway safety regulator to impose a 10 km/h speed limit on the new cross-city line, the Oireachtas transport committee has heard.

Cormac O’Rourke, chairman of Transport Infrastructure Ireland, told TDs and Senators the temporary speed limit was imposed “at the last minute” by the Commission for Railway Regulation and had “not been anticipated”.

He said a fast walking pace was 6km/h so the Luas speed “is not much more then that”. He likened this to a “slow jogging pace” but said speeds would improve over time.

Mr O’Rourke blamed many of the problems with the cross-city line on the behaviour of other road users including pedestrians. He said a recent incident on O’Connell Bridge, where a longer Luas tram blocked traffic on the quays, was caused by a car failing to clear a yellow box at a junction. Gardaí were now policing places where there was potential for this to happen, he said.

He said the prioritisation of different forms of transport in the city was a matter for the National Transport Authority, while the sequencing of traffic lights was a matter for the city council.

‘Optimisation’ He said it was hoped that “with gradual optimisation and the removal of the 10km/h speed limit on O’Connell Street” that journey times would improve.

“While I know that it is no comfort to those stuck in traffic jams or feeling squashed on the Luas, it is worth pointing out that congestion is a symptom of economic success,” he said.

Social Democrats TD Catherine Murphy said Dublin Bus had carried out modelling and had forecast that College Green would be a problem when the new Luas line was introduced and this had not been properly considered. The State was creating a problem and working back form it, she said.

Ray Coyne, chief executive of Dublin Bus, said the company had been moving buses from the College Green route since 2010 and would move more if required.

He said Dublin Bus transported 39 per cent of customers into the city’s retail core and 60 per cent of commuters. The remaining routes across College Green were there because that is where the passengers wanted to go, he said.

‘Pinch point’ Conor Faughnan, of AA Roadwatch, told the committee it was almost a decade since private cars were blamed for the congestion in College Green and now taxis were being blamed. The reality, he said, was buses and trams could not both pass “the pinch point in front of Trinity College”.

“Luas can’t move so the buses just have to. You may as well get used to it”, Mr Faughnan said.

Agreeing with Mr Faughnan, Green Party leader Eamon Ryan said the problems with capacity at College Green had been predicted in the mid to late 1990s, when the city was working off the transport strategy A Platform For Change.

He said Mr Faughnan had “hit the nail on the head” with the analysis that the tram could not move so the buses “will have to”.

Mr Ryan also said he had taken a fall of his bicycle on the new Luas tracks.

“I am a very experienced cyclist, very comfortable on streets, well able to cycle in Dublin. I am terrified going around, coming from Pearse Street direction going right up Dame Street,” he said. “It is incredible that anyone designed that facility with cyclists in mind. I’d be interested to know who put that in.”