Infrastructure Partnerships Australia chief executive Brendan Lyon said road funding was broken in Australia and the ACT was perfectly placed to trial new initiatives and ensure better value for money.

"At its most fundamental, transport is broken because we don't have the money needed for new and renewed infrastructure and we use the networks we have very poorly," he said.

With an election looming, the Liberal and Labor parties have pledged to upgrade arterial roads including the duplication of the Cotter Road at an estimated $25 million, despite opposition from the ACT Greens.

The Liberals have also pledged $146 million for the duplication of Gundaroo Drive and a new flyover on the Barton Highway near Gungahlin.

The government has already spent more than $3 million on upgrades to the city to Gungahlin corridor for the construction of the light rail line, which is outside the $783 million price tag for the tram line.

Mr Lyon called on Chief Minister and Treasurer Andrew Barr to implement charges based on distances travelled, traffic congestion and road access in place of stamp duty, registration and fuel excise fees.

"This problem can and will be fixed by pricing reforms that spread capital city peaks, better recover freight costs and make the system fairer and better for motorists," he said.

"The transport network is costing us time and money because we cannot afford the new road and rail infrastructure we need and we use what we already have badly."

Economic modelling conducted by the group, which represents major construction companies and consultancies, is based on a similar road pricing model operating in the US state of Oregon.

"Our modelling shows that a fairer and better pricing system would have a tiny, 37¢ per week impact on the average Canberran road user, but would give them better maintained, safer roads and faster journey times," said Mr Lyon.

The model could see Canberra motorists charged 3.77¢ per kilometre with a congestion charge of 7¢ during the morning peak and 6¢ during the afternoon peak. Motorists would also be charged a weekly road access fee of $1.10 a week.

A spokesman for the ACT government rejected the proposal on Friday and said the territory would not be a trial site.

"A larger city such as Sydney with an established network of priced roads and significant and broad periods of road congestion even outside the traditional morning and afternoon peaks would be more suitable," he said.

"We understand that Sydney has undertaken early tests of basic road pricing through its time of day tolling for the Sydney Harbour Tunnel and Bridge."

Mr Lyon said he understood many voters would be concerned about such reforms but insisted they would be subject to detailed planning and trials.

"While it's easy for people to get scared of a pricing system based on time, distance and location of travel, our modelling shows it would fix most of the problems and give motorists much better travel times, for much fairer costs," he said.

"The NRMA and other peak motoring groups support a process to fix road pricing, because it's the key to better roads and better transport."

Department of Infrastructure and Regional Development modelling released last year found the cost of congestion on Canberra roads is set to double to $400 million by 2030 unless major projects are completed. The report also found the total kilometres travelled on ACT roads could increase from 3.9 billion to 5.2 billion by 2030.

The cost of congestion in Canberra has increased from $54 million in 1990 to $200 million in 2015, largely due to an increasing population in Gungahlin and Belconnen.

Nationally, the total cost of congestion is tipped to reach $30 billion in 2030. The costs have increased from $12.8 billion in 2010 to $16.5 billion this year.