Giving motorists the option to switch to fast-flowing lanes built alongside existing key routes - with fluctuating prices depending on traffic volumes - would enable them to escape gridlock while taking pressure off the free network.

Transurban, which operates Brisbane’s network of toll tunnels, bridges and roads, says express lanes have proven a success on one of America’s busiest routes - the Capital Beltway circling Washington DC.

A similar approach could work for increasingly clogged arterials in and out of Brisbane such as the M1 Pacific Motorway, Bruce Highway, Ipswich Motorway and Centenary Highway.

“If you put two extra lanes on the Pacific Motorway but said this will be tolled, the Government keeps the funding because it’s self-funding and you still have what you had yesterday,” Transurban Queensland general manager Wes Ballantine said.

“If you don’t want to pay a toll, you never have to pay a toll. But for the first time, you have a choice. You can actually jump the queue.

“The other thing we’ve done in the US is that cars with three or more people travel free, so for the first time there is a price incentive to carpool which is good for the environment.’’

Buses also use the high-speed routes.

A sophisticated algorithm raises and lowers the toll price depending on traffic density to ensure the express lanes remain at freeway speeds. “That gives you trip time certainty,” Mr Ballantine said.

“On average, drivers use this system twice a week. It’s about knowing that if you have somewhere you absolutely have to be on time, whether it’s the airport or a meeting, that you will be.”

Future Brisbane: How express lanes work Future Brisbane: How express lanes work

Initial resistance was quickly overcome because unlike tunnels, express lanes allowed users to clearly see the benefits because other traffic was stuck crawling right next to them.

“There’s a “Lexus lane” component to it because people think the rich will get a better run, but all of our research is that it is a whole range and the most common car on the road is a Toyota Corolla.

“The greatest number of users are lower socio-economic level - because, we think, things like the kids are in after-school care and it closes at 6pm and if I’m late there’s a $25 late fee. So I’m willing to pay an $8 toll to make sure I get there on time. That’s the sort of feedback we’re getting.”

Mr Ballantine said demand would continue to soar on routes over the coming decades as hundreds of thousands of residents travelled to work in the central city from the outer suburban areas of Moreton Bay, Ipswich and Logan as well as the Gold and Sunshine Coasts, despite more outer employment hubs.

“We are looking at massive growth to the southwest, massive growth to the west and massive growth to the north. People are travelling big distances,’’ he said.

Traffic modelling conducted for Transurban indicates a 50 per cent increase in overall volume over the next 20 years and a 75 per cent jump in congestion, with average speeds over the day falling by a fifth.

The southern section of the Centenary Highway is expected to see traffic more than double in two decades, with a 40 per cent increase on the northern end.

The Bruce Highway is forecast to be 35 per cent busier, and the Pacific and Ipswich Motorways 30 per cent heavier.

Mr Ballantine said it was impossible to keep “building our way out of trouble” and options to reduce demand on the network, such as more flexible working hours, should be considered.

“It just doesn’t make sense having everyone on the roads at the same time just to start work at 9am when most people don’t have to.

“I think a 3 per cent reduction in peak period traffic times would effectively have us all flowing.

“People have it in mind that you have to halve traffic to make it work. You don’t. We build roads for the peak.

Bernard Salt outlines Future Brisbane Bernard Salt outlines Future Brisbane

“Technology could also play a role in managing traffic flows. What about an app that says ‘if you leave work right now it will take you 45 minutes to get home, but if you leave in 15 minutes, it will take you 25’.”

Meanwhile, future drivers may be charged according to how many kilometres they travel, as Australia searches for a new way of paying to build and maintain our network of roads.

Motoring group RACQ and Transurban agree that the current formula — using registration and excise tax on fuel to fund roads — is unfair and unsustainable.

“If you can only afford a 1996 Commodore you’re paying $800 rego and you’re a fuel guzzler on the road versus someone who can buy an (electric) i3 BMW who pays $800 rego and effectively no fuel. So the person in the Commodore is funding a lot more of the road network than the person in the i3,’’ Transurban Queensland general manager Wes Ballantine said.

media_camera Alwyn and Natasha Green in the Clem 7 tunnel.

With the growth of fuel-efficient vehicles, fuel excise is falling and the spread of electric cars means it will dry up altogether eventually.

Likewise vehicle ownership — and registration revenue — is expected to drop as car-sharing increases. But RACQ chief communications officer Paul Turner said the idea that there would be fewer cars on the road, and less need for transport infrastructure, was flawed.

“The difference is vehicles won’t sit idle all day. A driverless car could drop me at work, pick up my dry-cleaning, take the dog to the vet, pick up my shopping and get me at the end of the day.’’

Transurban conducted a trial of three different user-pays models among more than 1,600 motorists in Melbourne in 2016 and found at the end that 60 per cent of drivers preferred a usage-based system to the current funding model.

A per-kilometre fee was three times more popular than a charge per trip or flat rate with capped kilometres.

Other options such as time-of-day charges and a mobile phone-type subscription are being looked at in further research.

Mr Ballantine said the results of the first stage showed the public was open to the idea of reform. The findings are now being considered by the Federal Government.

Mr Turner said the technology to track and bill motorists according to use already existed and was being tested in other countries.

The RACQ was open to discussing user-pays models, including different prices for different locations or different times of day. “But it has to replace some of the existing costs such as stamp duty, fuel tax and rego. It can’t just be another slug to the pockets of motorists.’’

Chamber of Commerce and Industry Queensland general manager advocacy Kate Whittle said: “The only way we can have a sensible conversation about flexible working hours and working from home is to have critical digital infrastructure in place and we just don’t.

“The rollout of the NBN has been an enormous disppointment. If you look at comparable economies overseas, we are just so far behind.”