Most days Blackmans Bay resident Kali Bean runs the gauntlet of peak-hour traffic on the Southern Outlet to get herself to work and her two children to school in Hobart.

Key points: Hobart is grappling with a problem it's never had before: traffic

Hobart is grappling with a problem it's never had before: traffic Motorists are reporting their commutes are doubling

Motorists are reporting their commutes are doubling Experts say investing in wider roads would only provide a temporary fix, and that Hobartians need to shift to carpooling and public transport

A decade ago her morning trip took 20 minutes. Now the journey takes at least twice as long.

"We normally allow about 50 minutes when I'm doing a single-school drop off," Ms Bean says while stuck in traffic.

"If I'm doing a dual-school drop off it'll be over an hour."

Her biggest traffic bugbear? It's unpredictable.

"It's really hard to judge and really hard to guess what every day is going to be like," she said.

"If we're held up or it's a really bad day, we're often way past 9:00am getting the kids to school and myself getting to work.

"I'm forever apologising for being late."

It's not uncommon to be stuck in traffic on the outlet, but with one eye on the clock there's no time to enjoy the view of the sun rising over the Derwent.

The long peak-hour commute means Ms Bean no longer has the option of sending her children to schools close to home.

"A lot of schools don't let you drop off till 8.30am," she says.

"So for me to drop the kids off at 8:30am and then get up the outlet to town for work before 9:00am wouldn't happen."

Kali Bean says her morning commute has doubled. ( ABC News: Brian Tegg )

Eastern approach a slow slog

It's a similar story coming into the city over the Tasman Bridge from the eastern shore.

With more than 10,000 paid trips, Gerardo Erasmo is one of Hobart's most experienced Uber drivers.

He says traffic has become significantly worse in the last couple of years, often doubling the morning commute time.

Hobart Uber driver Gerardo Erasmo thinks a congestion tax might help cut traffic in Hobart's city centre. ( ABC News: Mitchell Woolnough )

"The worst traffic point is when you come from the bridge to get to the CBD, because the queue starts from Rosny Park [More than a kilometre away]," he said while driving along the Tasman Highway.

Crunch time: bigger roads or better public transport?

Hobart's traffic management has reached a crossroad and whichever way it veers — there's no turning back.

That's the assessment of internationally regarded traffic experts who say Hobart must now make a strategic decision to either expand its road network or invest in public transport.

Hobart's traffic is managed from one room in North Hobart. ( ABC News: Peter Curtis )

Graham Currie, professor of transport engineering at Melbourne's Monash University, says "Hobart has a choice to make".

"It can either continue building more roads, or it can try to look at more efficient ways of travelling around the city," he says.

"It's a choice about how you want Hobart to look in the future. Do you want it to be more European-like, or more like a Los Angeles and a car-based city?

"I would advise against a purely car-based strategy because you will get an outcome like a Los Angeles, which is not what you want to be in the future."

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Professor Currie believes the continued expansion of Hobart's road networks will begin to erode the charm and liveability of the city.

"Building billion-dollar roads to deal with the issue kind of sets you up for continuously growing road traffic and it means the inner-city areas will be dominated by parking," he says.

Dr Geoffrey Clifton, a senior lecturer in transport and logistics at Sydney University agrees.

"Every time you build new road infrastructure you're encouraging more people to drive," he says.

Dr Clifton says the Southern Outlet is a great case study, where plans to build a fifth lane could have fleeting benefits.

"There will be people [currently] avoiding driving through that area at the moment because the traffic's too bad," he said.

"As soon as you build new infrastructure it [traffic] gets slightly better … the people who get driven away come back … and then the traffic just builds up again very quickly."

A fifth lane on the Southern Outlet might improve travel times along the highway, but will probably exacerbate the morning bottle neck into Macquarie Street in the CBD.

"You can end up getting trapped in a cycle of engineering where you're constantly having to fix one choke point up after the other, without ever really improving things for ordinary motorists," Dr Clifton says.

A growing problem

While Hobartians are desperately seeking traffic relief, travel times are unlikely to reduce any time soon — if at all.

Traffic in Hobart is no joke, despite what motorists on the mainland might think. ( ABC News: Ros Lehman )

The population is expected to grow by another 30,000 people in the next decade.

Professor Currie believes Hobart should determine it's road strategy based on what kind of city people want it to become, rather than road strategy shaping the city.

"The quality of Hobart at the moment is its great historical legacy — its fantastic buildings and the walkable areas are very attractive to tourists," he said.

"I think you want to encourage that and road access and parking is not going to be very attractive if you increase that."

"Most people in Hobart currently drive because they have little choice.

"But I think as the city grows and if you can encourage development and activity in a central areas, the choices for more walk access and cycling and public transport will become clearer," said Professor Currie.

Hobart needs to drive cultural change

Eighty-three per cent of Hobartians drive to work — the highest percentage of any Australian capital city.

State Roads general manager Shane Gregory told the ABC's Curious Hobart team, if just 10 per cent of people car pooled, the roads would be like school holidays every day.

The Southern Outlet flow into Hobart in the morning can grind to halt with just one incident. ( ABC News )

But car-pooling is not on option for many people, including Ms Bean, who plans her commute around her children.

"Connor's only in [kindergarten] so Monday, Tuesday I'm dropping him at day care before I take Riley to school," she said.

"I'm here, there and everywhere with my car. I couldn't rely on somebody else."

Dr Clifton says getting people out of their cars is not easy.

"We're all used to using our cars by now and we get a lot of benefits from using our cars, so it's about slowly driving a change by improving the alternatives."

The main alternative is public transport, but Hobart has the lowest level of any Australian capital city.

"Globally, cities the same size Hobart have made good use of their bus network by creating corridors of high frequency services," Dr Clifton says.

"That means concentrating your bus services down the main roads rather than trying to spread it across the whole of the city.

"It might mean a few people have to walk a bit further, but more people live close to a frequent bus service and once you've got a frequent bus service near your door it allows you to leave your car behind."

Buses paving the way for light rail

Dr Clifton thinks encouraging Hobartians to use buses now is also important for building the case for light rail in the future.

More Hobartians should start using public transport now if the city wants to make a case for light rail, experts say. ( ABC News: Phoebe Hosier )

"I don't think light rail is a viable option in the short term for Hobart, but if we can improve the bus network in Hobart get more people using services along the corridors that we're interested in, get more apartments being developed around there ... to give people the option to live close to public transport; then eventually it starts to become viable to build light rail systems," he says.

"I think realistically a city like Hobart should be thinking about light rail over the next 15 to 20 years rather than the next five to 10 years.

"In the next five to 10 years it'll be about building better bus networks using the existing resources and starting to drive the behaviour change to get people used to using public transport, which will be necessary if you want to use light rail in the future."

Time for a congestion tax?

Mr Erasmo thinks Hobart needs some type of congestion tax to keep cars out of the city.

"Pay a little bit more if you are going to go into the heart of the CBD, then this discourages people to get into the CBD with a car," he says.

Dr Clifton says the concept of road-user pricing has been successfully adopted in London, Stockholm and Singapore.

"Road-user pricing charges people for how they use the roads," he says.

"So if you're travelling in peak hour you'd pay a bit more, if you're traveling off peak you'd pay a bit less.

"If you're driving through the Southern Outlet choke point in peak hour, driving a noisy polluting old car, then you're probably going to be paying a lot of money."

Traffic experts are encouraging more people in Hobart to use public transport. ( ABC News: Brian Tegg )

Dr Clifton wants road-user pricing introduced across Australia and he believes it could fund Hobart's road and public transport projects, while also reducing congestion.

"In the longer term road-user pricing is almost certainly inevitable with the growth of electric vehicles," he says.

"The tax take from fuel excise is going to decrease because electric vehicles don't use petrol."

Which begs the question: would Hobart traffic still be considered a major problem if the solution meant giving a big new tax the green light?