Immediately after becoming prime minister, Mr Turnbull indicated he would continue to take the bus or train where practicable. Then, days later, at the unveiling of his ministry, Mr Turnbull announced a new cabinet post, Minister for Cities and the Built Environment, to be filled by Jamie Briggs.

One of Mr Briggs' first briefs, it has emerged this week, is to talk with the states and territories on proposals that might help reduce transport gridlock in the nation's major cities. Urban rail networks are reportedly high on the agenda, though Mr Turnbull has said, correctly, that infrastructure projects will be assessed on their merits without discrimination against one transport mode or another.

It is a significant departure from the Abbott government's infrastructure approach, which favoured road-building over rail construction to the point of raising eyebrows among transport and urban planners. The Badgerys Creek airport announcement of early 2014, when the Coalition promised $1.2 billion to upgrade three roads around the new airport, but nothing for a rail link, was an instance of this foolish bias. It reached its zenith in December 2014 when the then prime minister threatened to withhold $3 billion the Coalition had promised for Melbourne's East West Road link if the incoming Andrews government used it for any other purpose.

The apparent abandonment of this ideological aversion to rail has been welcomed by governments and planners alike. Australia is one of the world's most heavily urbanised societies, and becoming more so. The rapid growth of Melbourne and Sydney has frequently outpaced the provision of adequate public transport options in their outer suburbs – condemning workers to ever-longer commutes and stymying the quick and efficient movement of goods and service.

The key to clearing these grid-locked roads and renewing the built environment lies, fairly obviously, in integrated planning and transport strategies prepared on behalf of federal, state and local governments. Yet, Mr Turnbull's creation of a cabinet post devoted to just that outcome probably ranks as the most important development of its kind since the creation of the Department of Urban and Regional Development 40 years ago by the Whitlam government. DURD's priorities included sewerage installation in outer city suburbs, the establishment of state land banks, and Albury-Wodonga's expansion as a means of relieving growth pressures on Sydney and Melbourne. The decentralisation exercise was only a modest success, but DURD's other accomplishments were significant and long-lasting. Small wonder state governments have welcomed it.

The Andrews government, which went to last year's Victorian state election with a specific commitment to prioritise rail over roads in infrastructure spending, is expected to renew its push to divert Commonwealth money set aside for the East West Link into passenger rail projects. Here in the ACT, the Barr government, which has not fully succeeded in selling its proposed Civic-Gungahlin light rail project to a skeptical public, will draw comfort from Mr Turnbull's change of tack, too. But it should not delude itself into thinking there may be more Commonwealth funding in the offing.

As Mr Turnbull has made clear, the Coalition has not turned train-spotter, and will keep an open mind as to which public transport option best fits a city's needs. Having ruled out bus rapid transit lanes and (more recently) questioned the need for the duplication of the Cotter Road between Curtin and the Tuggeranong parkway (a link subject to growing traffic as a result of new housing developments in the Molonglo Valley) it might be argued the Barr government is yet to demonstrate any particularly strategic approach to urban transport provision.

There's clearly more that needs to be done if Australia's big cities are to be unclogged and their amenities improved: Malcolm Turnbull's enterprise and belief in the necessity of good public transport ensures a promising start to the effort.