The National Roads Authority is "Neanderthal" in its terms of reference and needs to be "shaken from top to tail" to be turned into a modern body, according to the Green Party.
"We want to take all transportation issues and put them under an umbrella body, that unites and integrates transportation planning and gives it a strong environmental mandate," said Mr Ciarán Cuffe (Dún Laoghaire).
He was speaking during a debate on his party's Private Members' Bill for the establishment of a transport authority.
An umbrella body would help unite the "plethora" of agencies dealing with transport, Mr Cuffe said. Only 20 per cent of funding was for public transport.
The party leader, Mr Trevor Sargent, said capital investment on roads this year would be €1,249 million compared with €261 million for public transport.
"Our obsession with building new roads has turned our cities into places of mobilisation rather than civilisation."