Canberra is a city at a crossroads - predictions of a future plagued by clogged roadways, frustrated commuters and failing public transport has Canberra divided over how to move forward.

The ACT Government has long argued that investment in public transport - specifically light rail - is the solution, with the territory's population expected to reach 500,000 over the next 20 years.

By that time they warn it could take almost an hour for Gungahlin's booming population of 60,000 in Canberra's north to drive to the city.

The solution, according to the Government, is a 12-kilometre tram line that would run between Gungahlin and the city, with plans to expand the route to the Parliamentary Triangle, Woden and Fyshwick.

For stage one of the route, the first tram will roll out from Gungahlin Place at 6:00am, and then again every six minutes during peak times.

From there it is just 12 more stops to Civic.

Traffic lights along the route will know the tram is coming and automatically give it the right of way and the final stop will pull up just short of the city's bus interchange.

The Government said, with light rail, passengers could cut the journey time from Gungahlin Town Centre to the city to just 25 minutes.

The Great Crace Commuter Race

To put this claim to the test, ABC News Canberra examined how long it would take a cyclist, motorist and bus passenger to get to the city from Crace - Gungahlin's fastest growing suburb.

Sorry, this video has expired The Great Crace Race Part 1

Even during the morning peak hour, the car and bicycle are out in front, as the bus passenger (like future tram passengers) first has to make it to Gungahlin town centre.

From start to finish it was a huge victory for the bike, which was miles ahead of the competition.

Sorry, this video has expired The Great Crace Race Part 2

Parking really cost the car but it still won out over the bus and phantom tram.

Though both tram and bus passengers were delayed by their initial travel time to Gungahlin Town Centre, having right of way gave the tram a real boost over the bus.

History of light rail

Northbourne Avenue as it looks today. Many of the trees along the city's main thoroughfare would be removed to make way for light rail. ( ABC News: Greg Nelson )

One month out from the last ACT election in 2012, then Labor chief minister Katy Gallagher and Minister Simon Corbell stood beside Northbourne Avenue to announce that if re-elected they would put decades of debate behind them and commit to something called Capital Metro.

As a result of that election, Labor struck a deal with the sole Greens member Shane Rattenbury, cementing light rail's imminent, if not controversial arrival in the capital.

Since then lobby groups have sprung up, opinion polls been run and the posturing has become increasingly loud.

Aside from the cost, coming in at about $800,000 for stage one, lobby groups have raised concerns over construction and the loss of trees on Canberra's main transport corridor Northbourne Avenue.

They said any temporary construction pain was likely to pale in significance to the more permanent scarring of the National Capital's main entrance.

The Capital Metro plan involves removing Northbourne's trees to make way for the tram's overhead electrical wires.

Even with mature re-plantings, it could take years for the boulevard to regain its stately shade cover.

Others have raised concerns about the "pearls on a string" theory, where trams link as many high spots of activity as possible along the route.

Some have claimed that stage one of the tram line would not link many high-activity areas like hospitals, schools, shopping malls and office blocks and would not provide a steady flow of passengers in both directions throughout the day.

To remedy this, the ACT Government is considering extending stage one by three kilometres through the city and out to Russell.

By adding more "pearls" to the "string", such as the National Convention Centre, Canberra Institute of Technology and major defence and national security offices, the Government estimated it could increase the number of passengers by 30 per cent.

Buses versus trams

Buses and trams would create different futures for Canberra. ( ABC News: Greg Nelson )

A busway or rapid bus transit system has long been considered a great option for Canberra, especially between Gungahlin and the city.

Like light rail the buses have their own space, separate from the traffic.

The speed and service are on par with rail, but buses have the advantage of flexibility, able to peel off the busway and into suburbs - all for around half the cost of rail.

Sorry, this video has expired Benefit cost ratio of light rail in Canberra

But major public transport systems also change the way a city operates and light rail's inflexibility can also be an advantage.

Around the world the experience has been that property prices surrounding light rail stations rise, new businesses quickly move in, new apartment blocks tower up and tired and run down sections of a city can be revitalised.

Whether it makes logical sense or not, the same level of city shaping is generally not seen with buses.

So, the argument becomes one of not just about public transport, but also one of public values.

Decision makers weigh in

With the battle for and against light rail raging, ABC News Canberra talked to key decision makers about what this massive piece of infrastructure would mean for the ACT.

Matthew Burke

Griffith University's senior transport planner Matthew Burke. ( ABC News )

Griffith University senior transport planner Matthew Burke said his advice for Canberra would be to rapidly move ahead with stages two and three of light rail after completing stage one.

"You've got to build a network through the Parliamentary Triangle, connect to Woden, hopefully beyond and get a network that really works," he said.

"You're at risk if you only build stage one of having a piece of infrastructure that's delightful for people in that corridor, [it] may lead in the long term to some land uplift in that corridor but is pretty sub-optimal as an overall part of the public transport network."

But, Mr Burke said if Canberra continued to shape more of its development into apartment towers in the inner suburbs and at key nodes along the corridors, light rail would start to make more sense.

"Then there's the decision about when you bite the bullet to invest, that time could be now, it could be 10 years from now," he said.

"I'm not a Canberran. I'm very glad I don't have to make that call."

Geoffrey Clifton

University of Sydney transport economist Geoffrey Clifton. ( ABC News: Greg Nelson )

University of Sydney transport economist Geoffrey Clifton said whether light rail was the right choice was about city planning and the future look of Canberra.

"The question Canberrans need to be asking themselves is what city do they want Canberra to be looking like in 10, 15, 20 years and then ask the politicians how will your plan help to deliver the city that I want to live in," he said.

"[You can] continue as you are - a very highly car dependant city but one in which most people have access to a back garden, there's lots of trees, tree lined boulevards, the bush capital feel that we all know and love.

"Unfortunately continuing down that route means people will be travelling further to school, work, education, leisure. It also will have environmental impacts."

Corrine Mulley

University of Sydney senior transport economist Corinne Mulley. ( ABC News: Greg Nelson )

University of Sydney senior transport economist Corinne Mulley said the decision came down to more than whether buses or trams were more cost effective.

"I think if I was given the choice between a light rail system or a bus system I would always go for light rail," she said.

"But I don't think that's the right question. The right question is 'would you like to have two kilometres of light rail or a whole network of bus rapid transit?'

"I think politicians like to cut ribbons and I think politicians would do well to do what it is that the punters actually want in terms of their public transport.

"I think what they want is to be able to walk up to a stop and for something to come that's quick and frequent. They don't want to wait for it.

"I think most punters won't mind what shape the body of the vehicle is."

Leo Dobes

Australian National University economist Dr Leo Dobes. ( ABC News: Greg Nelson )

Australian National University economist Leo Dobes said the Canberra community owed it to themselves to examine all the options.

"The public could do no worse than asking the Government to produce a study which looks at the benefits and costs of a tram," he said.

"So that an informed debate can take place as to what we should best do with our money.

"If you're just looking at a tram or no tram then you're more or less specifying the answer upfront.

"You're saying the only choice is a tram and if we can bump up our benefits to look as if they're higher than the costs the answer is obvious it's going to be a tram.

"That's not really having a proper look at all the ways we could best spend our money."

Emma Thomas

Capital Metro Agency director general Emma Thomas. ( ABC News: Greg Nelson )

Capital Metro project director Emma Thomas said Canberrans should be brave and embrace new possibilities.

"I would just encourage people to have a really open mind about the possibilities that a better public transport system creates," she said.

"And what Canberra can be in the future because of this, rather than just shutting it out at this point in time and trying to do the same as what we've always done before."

Simon Corbell

Capital Metro Minister Simon Corbell. ( ABC News: Greg Nelson )

Capital Metro Minister Simon Corbell said Canberra was "ready for the change" to light rail.

"People who are used to Canberra being a smaller town, 200,000 people, easy to get around, lots of free car parking, that Canberra's gone," he said.

"Our city is growing up. It's bigger, it's more complex and it's facing the challenges that other cities face. It's a critical turning point.

"At one level, this is a leap of faith for our city but other cities that have made this leap have benefited and seen the dividend time and time again.

"Once this line is in place we will see great optimism I think, about public transport and what it means for this city."

Alistair Coe

ACT Opposition light rail spokesman Alistair Coe. ( ABC News: Greg Nelson )

Opposition spokesman Alistair Coe said if elected in 2016, the Canberra Liberals would cancel any light rail contracts and rip up the tracks themselves if they were already in the ground.

"Is light rail the number one priority for Canberrans? Or would Canberrans rather see that money invested in health services, or in education services or in community services and improvements to buses and many other priorities?" he said.

"I simply don't accept that building a line from Gungahlin to the city or Gungahlin to the city and Russell and even a broader network is going to be city-changing.

"The reality is the history of Canberra and the design of Canberra lends itself to travelling fairly large distances.

"I think it's fair to say that for the foreseeable future, the private motor car is going to be most Canberrans mode of choice for travelling around this city."

Shane Rattenbury

ACT Greens Minister Shane Rattenbury. ( ABC News: Greg Nelson )

ACT Greens MLA Shane Rattenbury said Canberra was not going to change overnight, but if the city did not want to be dominated by cars, changes had to be made now.

"Certainly people say 'we should emphasise other areas like health and education', well health and education between them already take more than half the ACT budget every year," he said.

"We do spend significantly in those areas and there's other areas we need to invest in.

"Because if we don't invest seriously in public transport we will see what an impact population growth and congestion will have on this city and we can't afford not to address that.

"This is about saying we're at a point in Canberra where we have to decide what our future's going to be. This is going to be the key discussion at the next ACT election.

"What is the vision for the future of this city? Is it more cars, more lanes of traffic, more car parks, using up the valuable land in our city? Or is it about building a modern city for the future?"