The promises the Coalition is making on transport are the primary selling point for its decision to lease 49 per cent of key electricity assets for a $20-billion odd return.

And they are certainly ambitious, even if they would take years to build. The largest pledge, in terms of cost to the state budget, is another $10 billion rail tunnel under Sydney Harbour and through the central business district.

This tunnel, which would be the first addition of rail capacity to the city since the construction of the Eastern Suburbs Line in the 1970s, would connect the $8.3 billion North West Rail Link, which is taking over the existing Epping to Chatswood Line, to the Bankstown Line at Sydenham, adding at least three new train stations to the city.

But if they're not already, the government's plans for this line are surely to become more controversial in the years to come. Transport Minister Gladys Berejiklian's decision to run automated single-deck trains on the North West Rail Link, operated by a private company, means the existing Epping to Chatswood Line would need to be closed for about seven months in 2017 or 2018 to make it compatible with the new system.

Students at Macquarie University, and workers at Macquarie Park, who currently catch trains to work and school will need to switch to buses for more than six months.

And when the second harbour crossing is built, some time at the start of the next decade, there will be even bigger disruption to the Bankstown Line. The 17,000-odd commuters who catch Bankstown Line trains to the city every morning would also need to switch to buses, perhaps for longer than six months.

But the curious thing about this election campaign is that the Labor opposition has not been out picking holes in government transport policies. As Mike Baird and his ministers have been keen to point out, this election sees the bizarre situation in which the opposition does not want to talk about Sydney's traffic and congestion.

Labor's plans, which it has described as modest, would largely mirror the Coalition's policies. But Labor, without the $20 billion expected to be raised from the partial privatisation of electricity assets, would delay the construction of the second harbour rail crossing, and also shave off about a third of the WestConnex motorway, the other big-ticket item promised by Baird and the Coalition.

The 33-kilometre toll road, which would also not be finished until 2023, would provide another M5 East Tunnel, a new M4 East Tunnel from Homebush to Rozelle, and then a tunnel under the inner-west to link them. Labor says it would scrap the linking tunnel, which WestConnex says is the most important element of the whole project.

And while there is plenty of controversy over whether the motorway is the right thing to be building, there is little question the roads it would alleviate – Parramatta Road and the M5 East – need some improvement. The Greens say they would scrap the entire motorway altogether, and instead build a rail line between Epping and Parramatta.

What the experts say

Associate Professor Garry Glazebrook from the University of Technology, Sydney, is an experienced transport and urban planner.

Dr Glazebrook says it is unfortunate that both major parties have committed to WestConnex, or in Labor's case most of WestConnex.

"What's wrong with that, you might ask as you sit in Sydney's notorious traffic?" says Glazebrook. He offers five reasons.

The first is that there has been a shift to increased use of public transport, as opposed to the car.

The second is that WestConnex would encourage more cars into Eastern Sydney, where streets can't accommodate them.

The third is that more jobs should be encouraged in Parramatta and other western centres, and more roads in eastern Sydney would not do that.

"Fourth the development of Badgerys Creek airport, the Southern Sydney freight line and intermodal terminals at Enfield and Moorebank undermine the need for the duplication of the M5 component of WestConnex," he says.

And fifth, the last four toll roads in Australia have gone broke, creating a financial risk for the state.

"I would suggest an alternative, multi-modal plan. This would include a much smaller two-lane tunnel linking the Airport/port to Strathfield, but limited to commercial vehicles, taxis and buses in peak hours; a West Metro built in stages between the CBD and Parramatta; and additional park and ride capacity on the East Hills line, at Strathfield near the end of the M4, and at the new stations on the West Metro."

Professor Michiel Bliemer is chair in transport and logistics network modelling at the University of Sydney.

Professor Bliemer says that Sydney has been shaped by the Great Australian Dream, which is the belief that everyone should have access to a house and garden.

"As a result," Professor Bliemer says, "extensive urban sprawl and suburbanisation has occurred and in order to enable travelling to these suburbs, tramways were removed in the 1950s to make way for roads for cars. Since then Sydney has seen rapid growth. Being a car-centric city with low-density housing, traffic has turned Sydney into a gridlock."

He says the most important priority for Sydney, therefore, is to increase the density of housing in dedicated areas of the city while providing high quality public transport between those areas.

"Simply building more roads will not solve the congestion problems in the city (see California), and do you really want to live next to a big (polluting) road?" he asks.

"In the past decade there is a growing understanding that a liveable city is a walkable city, in which public transport and green areas play an important role. Living close to a train or metro station is desirable. Land prices increase as accessibility to public transport increases. If governments can capture this value and invest it in better transport infrastructure, we all gain. An important question that we have to ask ourselves is: how much are we willing to pay for an improved transport system, knowing that current tax revenues are not sufficient to achieve this?"

Sandy Thomas is an experienced consultant and one of the authors of the Herald's Transport Inquiry of 2009 and 2010

"The saddest aspects of the major parties' transport policies are their triviality and their similarity," says Thomas.

Thomas is highly critical of the manner in which transport planning, under both Labor and Liberal, has been taken away from transport service planners within government and handed to a new generation of bureaucrats who prioritise building things.

He is also critical of the impending privatisation of much of Sydney's rail network.

While the two major parties obviously differ on the future of the electricity network , they are as one when it comes to the privatisation, by stealth, of Sydney's public transport.

"The government has already contracted to privatise the new, publicly funded $2.4 billion Epping-Chatswood railway by quietly giving it away, for nothing, to the private operator of the North West Rail Link, a consortium led by the Hong Kong-based MTR," Thomas says.

"And now both the Liberals and Labor, in the former case as a "benefit" of the electricity privatisation and in the latter case seemingly without realising it, propose to privatise the Bankstown-Sydenham section of the publicly owned Bankstown rail line as well, as part of the "second harbour rail crossing" project," he says.