Fast, reliable buses and safe lanes for e-bikes could be better than switching one type of car for another, researchers say. Photo: Supplied/ Auckland Transport
A mass switch from petrol-powered to electric vehicles will result in more road injuries, a study out of Otago University has found.
That's because the fuel savings provided by EVs will prompt people to drive more.
Transport and climate researchers say rolling out other measures - like fast, reliable buses and safe lanes for e-bikes - would be a better way to get both health and climate benefits than switching driving one type of car for another.
Otago University's Dr Caroline Shaw led the study calculating the health impacts of switching from fossil fuel to electric vehicles, if nothing was done to help people access better alternatives to driving.
Otago University Associate Professor Caroline Shaw. Photo: SUPPLIED
She found a gradual shift to around three quarters of vehicles being EVs by 2050 would lower carbon emissions, but could also cost the country millions more in health costs.
While previous studies focussed on tailpipe emissions, this one also looked at driver behaviour.
"When the price decreases of petrol and diesel people drive a bit more, so we basically said ok we know electric vehicles are quite a lot cheaper to drive so let's make the assumption it's a similar kind of change, and what happens is when the price decreases and people drive more, the risk of injury increases," she said.
More driving also increased air pollution from vehicles' tyres, she said. EVs lowered health impacts and deaths from tailpipe air pollution, but that was balanced by increased motor vehicle injuries and deaths from more driving.
Dr Shaw said there were other ways to get quick wins for living costs, health and the climate, namely by making it easier to e-bike and catch faster, more convenient buses. Rail was also very helpful, but harder to roll out quickly at scale, she said.
"Buses are great because we can put buses in and we can do it quite quickly they don't need a whole heap of hard infrastructure like trains or light rail, not that I'm against either of those," she said.
University of Auckland senior planning lecturer Dr Tim Welch agreed.
He said just switching out one type of car for another without changing anything else only worsened congestion, meaning fossil fuel cars, EVs and buses sat in traffic longer.
He said the transport system needed re-balancing to give people real alternatives to driving.
"It makes sense that things like electric buses, operated by the government, and owned by the government, are a much more efficient way to reduce emissions than asking people to open their wallets and buy a new car, and buy the charging infrastructure, because otherwise they should feel guilty or whatever."
Both researchers said the key to getting people to want to ride buses was providing fast, dedicated bus lanes - which cities such as Auckland already did on some routes, with plans for more.
On Auckland's North Shore, the Northern Express bus to the CBD, which has its own dedicated busway, clocked 7 million passenger trips over the year to June.
Figures from Auckland Transport or AT show total monthly bus patronage on routes between west Auckland and the CBD grew rapidly after the western express or WX1 and two other new bus routes, replaced previous, less convenient routes in late 2023.
The popular double decker WX1 bus clocked almost one million passenger trips over the year to June, while all western express routes combined reached 1.8m.
The researchers said even diesel buses were more efficient and climate-friendly than driving because each buses carried so many more people and reduced congestion for cars on the roads.
Auckland Transport has 224 zero-emission buses, and plans to have 450 by August next year, about one-third of the total fleet.
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