There has been political obfuscation, dribbling of information on alternatives, grand political statements and then back-tracking, and seemingly top-down edicts by local politicians, including from the minister, Simon Corbell.

In fairness to Capital Metro, now responsible for the project, it currently has an explanatory exhibition in Civic and a website.

Last October the minister announced the trees on Northbourne would likely have to go, irrespective of the proposed tram system, because of technical problems with them.

Common sense suggests he ought to have amplified this in order to assuage community concern.

This and the seeming (to some people) ambiguity of financial aspects, exacerbated by floating the preposterous idea of a levy on ratepayers, was bound to have unintended consequences of continuing public unease and questioning.

We have also been subjected to tiresome waffle about examples to be emulated – as with the daft idea of comparing Canberra with Singapore, and cities elsewhere where comparison is inappropriate.

John Gray, responding to Corbell’s comment in a letter to the editor, suggested there was no indication of a will to save the 420 trees on Northbourne in light of its significance as a major entry to the city.

This ought to have prompted the minister to authorise release of information on the future of the trees. Why? Because the technical information existed, as did answers on what alternatives to using the median strip for the tracks were being explored.

For example, there was an option to site the tracks on the right-hand road lanes on Northbourne; however, problems were foreseen with right-turning vehicular traffic and cyclists.

A percentage of the 420 trees (eucalyptus elata) have a fungal infection and it is spreading. The trees will have to be replaced over the next decade irrespective of the tram. They were planted in about 1982-83 in an NCDC scheme initiated by Gray.

They replaced red box (E. blakelyi), planted by Lindsay Pryor in the 1940s, which in turn replaced deciduous trees planted by Charles Weston in 1921-23. The red box were extensively infected by lerp psyllid, a recurrent problem with this tree.

To mitigate the devastation of clear-felling the whole avenue of red box, sections were left in place while newly planted E. elata gained height.

Gray placed an explanatory piece in The Canberra Times on the what and why of the replanting. By doing this he avoided major criticism because people were informed. It is known as "civic engagement": treating people as important players in their city and bringing them into the information circle so they feel part of the process of change.

In putting forward the following further comments and information, and I acknowledge data supplied by Capital Metro, the assumption is made that the tram system will proceed.

Let me also add that my views on appropriateness or otherwise of the tram are immaterial to this article. Nevertheless, as a town planner I know that internationally cities of all sizes are seriously considering options for transport planning, including efficient public transport. Canberra’s population of about 380,000 will continue to grow, with predictions of 600,000 by mid-century.

It will still be a modest-sized city even then. In this regard it is similar to many medium-sized cities in Europe, for example Helsinki, where recently my wife and I spent a few days en route back to Australia.

Helsinki has a population of about 604,000 within a metropolitan area of about 1.07 million. It has an extensive tram system with impressive success in integrating the tracks and other infrastructure into the streetscapes through landscape design treatment.

While Helsinki shows the pleasing effect of avenue trees planted about 1.5 metres from the outer rails of the track, giving some idea of the effect that can be achieved on Northbourne, there are differences.

The track gauge in Helsinki is one metre. The planned system for Canberra is the more usual 1.43 metres, resulting in a required track slab width of 6.8 metres, plus 2.5 metres each side for potential impact works, giving total easement width needed of 11.8 metres. The slab widths and sides are narrower in the Helsinki example.

The two inner rows of E. elata on Northbourne are 10.5 metres apart and will have to be removed to accommodate the 11.8-metre easement.

The two outer lines of trees are 18.5 metres apart; however, their root systems are structurally enmeshed with the inner rows. To remove the inner row will likely lead to danger of wind throw of the outer rows: to keep these is not a safe option.

If 2016 is the start date for the tram, then certainly there will be clearing of the existing trees, but also a small window possibly to start some sections of replacement trees.

It is highly likely they will be eucalypts, and it is hoped that advanced stock can be used. If the start is delayed, then each year’s delay will give a longer window for replanting while temporarily retaining some existing trees. In these circumstances the visual impact would be ameliorated.

Regardless of whether the trees go rapidly or over a period of time, it is important to ask what it is about entering the national capital that we want to maintain in terms of sense of place.

Northbourne Avenue, with its symbolic values and meanings, is a landscape element of immense heritage value. We therefore have to take this opportunity through replanning to ensure it retains its values and to ask questions.

Should we, for example, think of different sections along the road with distinctive plantings as part of a harmonious whole? In this case, could we use a mixture of eucalypts and evergreens?

Certainly what we do not want or need is to cram a parallel continuous wall of high-rise buildings on the road edges simply to cash in on a development mentality at any cost.

We have a civic design opportunity to produce something that graces the city into the future, rather than being a disgrace. Whatever the outcome, it should include the process of civic engagement.

Professor Ken Taylor is with the Centre for Heritage and Museum Studies at the ANU. He and his wife travelled at their own expense to Europe and Helsinki.