The light rail control system, which collects GPS location data from light rail vehicles, sends requests to the traffic light system to either hold the green light to allow the light rail vehicle to pass or switch to a green light out of phase.

After the light rail vehicle has passed, the traffic light system returns to normal operation.

Drivers' exasperation, though, comes as one of the country's top experts on traffic systems says crossing lights in the ACT are timed against pedestrians.

Professor of Transport at the University of Sydney David Levinson said people on foot and bike should get longer to cross, giving cars shorter times on a green light.

On a recent rush-hour morning, The Canberra Times got the views of motorists as they sat at red lights on Macarthur Avenue waiting to enter Northbourne Avenue.

"My view is that they should do something about the timing of the traffic lights," said one. "The trams are being accommodated. This junction is backed up. It's never been like this before.

"For people coming up Macarthur [Avenue], I've just counted it and there's 20 seconds of green light." He didn't think that was long enough.

Another driver said, "The traffic going across Northbourne Avenue is definitely worse."

Some drivers in the area say they have seen road rage where people mount kerbs to get past stationary cars.

Transport Canberra figures from October show that more than 400 vehicles an hour travel eastbound on Wakefield Avenue during the morning peak period while 840 vehicles an hour travel in the same direction in the afternoon peak.

More than 600 vehicles an hour travel westbound on Macarthur Avenue towards Belconnen at the morning peak while 430 vehicles make the same trip each hour in the afternoon.

But as car drivers complain about delay, the traffic expert said that motorists get it too easy.

"You don't have to surrender to the automobile. Walking conditions for pedestrians should be better, and in a city like Canberra where distances are so great the conditions for pedestrians will never be perfect but that doesn't mean you can't get more than you currently get," Professor Levinson said.

He believed Canberra could do more to make life easier for pedestrians. Some cities, for example, have crossings where all vehicles stop at the same time and people on foot can cross in all directions – they're sometimes called "scramble crossings".

Whatever the long-term solution, part of the current problem is construction – and construction means delay before any planned improvement, in this case when the tram system comes into operation.

There is the question of whether traffic jams may push people from cars to public transport.

A Transport Canberra and City Services spokesman did not rule out that the new system was designed to encourage people to leave their cars at home.

"We plan to encourage more people onto public transport with our new network of light rail and more buses more often, which will start in time for school term two," he said.

Canberra traffic lights are controlled by the Sydney Co-ordinated Adaptive Traffic System, known as SCATS, which was originally developed by NSW transport authorities and since adapted for use in cities around the world.

The system measures traffic flows from detectors in roads approaching intersections to allocate green light time through each phase of the traffic lights.

Light rail vehicles have been given priority since March 1 during the testing phase. The network starts operation on April 20, pending regulatory approvals.

The original traffic impact assessment for light rail found there would be slower travel times across Northbourne Avenue for motorists after light rail vehicle priority was introduced.

A report prepared by the Australian Automobile Association in 2018 found Canberra had the third fastest average speeds in peak travel times in Australia, behind Brisbane and Darwin.

Canberra's roads also performed better in the afternoon peak period than the morning peak.

Average speeds in peak times had increased until 2016 and then began to decline sharply in 2018, the report found.