A new study has shown New Zealand's transport system could be contributing to increasing levels of psychological distress.
The report out of the University of Auckland is the first of its kind to look at the relationship between transport and mental health in Aotearoa.
It found the transport system was characterised by high usage of the mode which was most associated with poorer mental health outcomes: the car.
Roughly four out of every five commutes are done in a car, but research shows car trips of 15 minutes or longer can lead to poorer life satisfaction, poorer family life satisfaction, declining community participation and lower productivity at work.
And the trend is going the wrong way: in New Zealand, car ownership, car usage, and time spent in cars have all risen in the past two decades.
Meanwhile, active modes of transport which were typically associated with better mental health outcomes have actually declined since the 1970s.
"We tend to think that transport is a slightly annoying part of our day, but actually it can have quite a strongly negative impact on our mental health," said lead author of the report, Dr Kirsty Wild, from University of Auckland's School of Population Health.
"Conversely it can actually have some quite positive impacts depending on how we configure our transport system."
Transport is a mental health issue
The number of people reporting they are experiencing high levels of psychological distress has been increasing, according to the New Zealand Health Survey.
Prevalence amongst the population has risen from 4.5 percent in 2011/12, to 8.2 percent in 2018/19.
Levels of distress vary depending on community and age group, with young people, women, Māori and Pasifika all experiencing higher levels of mental health illnesses.
Meanwhile, the picture of transport in New Zealand is car-heavy.
Eighty-three percent of journeys to work were done in a car while the remaining modes - foot, bike, bus or train - account for 17 percent.
Car ownership has risen since 2000: there are now roughly eight cars to every ten people.
How journeys and mental health interact
Alicia Hall lives on Matiu/Somes Island with her husband - the island's DOC ranger - and their three kids.
When your house is on a 25-hectare island in the middle of the Wellington Harbour, there are only so many ways to move around.
"On the island it's walking, and then we take the ferry off, so we can either go to Days Bay or the city. So if we choose the city option, it means either public transport, walking, or taking bikes. And if we go to Days Bay it's taking the car."
As someone who uses pretty much every mode of transport available to a Wellingtonian, she's well placed to talk about how much transport can impact mental health.
And it does - take walking, for example.
"Because I'm just sort of walking around various places, I end up coming back on the ferry, and I feel good about my day. But if I'm in the city with my kids, that can be really stressful, because you [have] got to make sure they don't run out on the road, [and] there's a lot of competition for pedestrian areas, with e-scooters and sandwich boards."
But an average car ride for her isn't much better.
"So it'd be like getting groceries, dealing with car things, just sort of life stuff, taking kids to swimming or other classes that they do. And then trying to make sure we make the ferry, the last ferry home, it can be really stressful."
She has to deal with tight timeframes, trip chaining, and concerns over child safety.
These are things Dr Wild said many New Zealand women had to deal with.
"Because they have more care work, as well as paid work, they're really affected by commute stress, and longer commutes, because they have to get to more places.
"They're also responsible for kids' safety. People brought up in the lockdown survey that I did, just how nice it was to be able to go out with your kids on the street, and walk along, and there just be less traffic."
Consequences of New Zealand's transport system
Hall's experience with transport showed how it can impact wellbeing beyond just sitting in traffic.
Heavy car usage led to busier roads, which can cause anxiety for parents when walking children around busy areas. It also led to greater background noise and a hypervigilance over injury, which can contribute to anxiety.
Public transport was particularly worrying for low-income communities, who can experience transport poverty.
It can also isolate people and communities away from green or blue spaces, which in turn, were beneficial for mental wellbeing.
Then there is the concept of community severance, which is the idea that transport infrastructure is eroding neighbourhoods.
"People who live in really heavy traffic neighbourhoods: kids have less friends, and adults have less friends, than people who live in neighbourhoods with less traffic," Wild said.
"So our social connections kind of shrink."
Studies in New Zealand have also shown transport can lead to psychoterratic stress, which means "the separation from people and places of cultural and environmental significance to Māori".
Commuting: control, time and stimulation
The report suggested that commutes played an enormous part in life satisfaction and wellbeing.
"It's really a combination of how much control you have, how long it takes, and also how stimulating it is," Wild explained.
"For instance, people that drive and people that bike, they both have a lot of stimulation: you have to concentrate, you're looking around, there's lots to do. But people who bike have a lot of control, so they're most likely to find their commute exciting.
"People who drive a car - especially in congested conditions [with] longer trips - they have lots of stimulation, you have to concentrate, but lower levels of control. There's lots of stop-starting [and] it's much more frustrating."
She said people that drive were the most likely to find their commute stressful.
After about 15 minutes in a car, there is a drop in trip satisfaction, and after 40 minutes, there is a drop in life satisfaction.
"We're definitely getting up there in our trip commute length," Wild said.
"It's about 23 minutes average in Auckland, although for a lot of people it's a lot longer than that, so we're definitely getting into that zone."
Those who took public transport were most likely to find their commute boring - with low levels of stimulation and control - while walkers were most likely to find it relaxing.
Studies showed active transport - such as cycling - was better for the mind.
"It's a slowness than sitting in traffic and having that added stress of sitting in all of this traffic," said Miramar resident Christina Bellis, who cycles into Wellington's CBD every day.
"It's really good for your body to be moving, it moves your blood around and that moves the blood through your brain, and I think that all of that added together, as well as the fresh air, is really really incredible for calming ourselves or taking a moment or breathing a bit."