The head of a major Sydney business lobby group has come out swinging against the Baird and Abbott governments' road-building agenda, while also slamming the boss of the WestConnex project for trying to divide the city.

The chief executive of the Committee for Sydney, Tim Williams, told an audience at the University of Sydney last week all sides of politics had "got it wrong" on the city's transport priorities, criticising them for a lack of ambition in promoting public transport in the growing metropolis.

Dr Williams, whose organisation's members include major construction, finance and engineering firms, also called on the government to release the business cases for the new mega projects being proposed for Sydney which, to its detriment, remained in the thrall of road builders.

"There is no strategic or structural planner of Sydney at this point of time outside of RMS [Roads and Maritime Services]," Dr Williams told the Halloran Trust event at the university.

"RMS is the structural planner for Sydney," Dr Williams said, before quoting George Orwell to the effect that Sydney was "a family with the wrong members in control".

"I'm sorry to have to say it but I think it is, I think we've got problems," he said. "I think in its current form, RMS needs to be reconstructed."

Dr Williams' presentation largely reflected familiar themes advanced by transport academics and urban planners. As cities became denser, governments needed to fit them with better public transport, cycling and walking facilities, rather than focusing on new motorways that encourage sprawl and car use.

But the intervention is significant because it is rare for a big business group to press these points. Members of the Committee for Sydney include major engineering firms like Arup​ and AECOM, as well as finance companies like Macquarie Group, Westpac and ANZ.

"We are in the presence of another road transport upheaval in this city," Dr Williams said, while showing a slide of the $15 billion WestConnex motorway and its proposed extensions to the north and south.

"Which, by the way, we are not seeing in any other cities in the world," he said. "And that's the issue – many other cities in the world are taking their highway capacity out and I'm just wondering, what is so different about the Australian city experience that means that they're wrong and we are right?

"We think this is a congestion-busting proposition and nowhere in Christendom does that appear to be the case – so what's going on?"

For the most part, Dr Williams declined to specifically cite the WestConnex project, a 33-kilometre series of motorways largely through the inner west of Sydney.

But he aimed direct criticism at the chief executive of the WestConnex Delivery Authority, Dennis Cliche, for comments reported in the Herald in which Mr Cliche said those opposed to WestConnex were wealthier people in inner suburbs.

"They're not living in the mortgage belt. They don't have kids who are to some extent excluded socially from the opportunities that some people have," Mr Cliche said.

In his address, Dr Williams said this was a "terrible way to have a civic dialogue about transport in our city".

"Trying to set one part of the community against another, trying to say that the inner west community is trying to stop the good people of western Sydney getting access to something," Dr Williams said.

"This is the statement by the chief executive of the WestConnex Delivery Authority and more shame him. I know him and he's spoken to the Committee for Sydney," he said.

"I am astonished. I think he must be panicking. I don't think his masters would want the dialogue to be conducted like this.

"But also it's just wrong. Because if you are worried about the inequity of our city and access to public transport, there's really a good thing to do about it – give them access to public transport in western Sydney."

Contacted for comment, Mr Cliche said: "Sydney needs an integrated transport solution that includes both roads and public transport to keep our city moving. It is not an either/or proposition.

"WestConnex Delivery Authority is committed to engaging with our stakeholders as a core part of planning and delivering this project. We welcome constructive dialogue which will help ensure we deliver the best possible road infrastructure for Sydney."

Dr Williams called on the government to release the business case for the WestConnex project –  "the people who propose these massive projects, they haven't even bothered to show us the evidence" – but also criticised the lack of focus at the recent state election on alternative public transport proposals.

"For me it's a politically neutral thing, they've all got it wrong."

Dr Williams said what was needed was a transport "revolution" in Sydney, with aggressive targets to promote public transport use.

Separately, City of Sydney Lord Mayor Clover Moore has been campaigning against WestConnex and this week released a report querying its supposed benefits.

In response, Roads Minister Duncan Gay said: "While Clover Moore wastes ratepayers money on dubious traffic studies, she turns a blind eye to the thousands of motorists stuck on the M4 and M5 each day."

"Motorists battling the M4 and M5 every day, those stuck in gridlock on Parramatta Road, can't wait for WestConnex – they know to do nothing is not an option," Mr Gay said.

Concord tunnelling point announced

Separately, Mr Gay announced on Wednesday that a hockey field at Concord would make way for the motorway project's midway tunnelling point.

Players displaced by loss of the Cintra Park Hockey Field would be accommodated in "new and improved" facilities at the St Lukes Park precinct, said Mr Gay, who added the decision eliminated the need to acquire homes.

"The mid-point allows tunnelling work to be carried out in two directions from the one location, towards the M4 widening at Homebush Bay Drive and towards the end of the M4 East tunnel at Haberfield," he said.