Electric lines companies claim 24 charging stations would be needed on State Highway 1 from Kaitaia to Invercargill if the use of electric cars is to take hold here.
Uptake of electric cars is languishing in this country, but pressure to use them is expected to grow as a way of reducing greenhouse gas emissions.
The Electricity Networks Association said multiple charging stations would be needed.
Chief executive Graeme Peters said fast charging would take about 20 minutes and slow charging three to four hours, so charging stations would be best placed alongside cafes or picnic spots.
Mr Peters said electric-vehicle-only lanes on motorways would be an incentive to switch to electric cars.
He said there were several ways to encourage electric vehicles, or EVs.
"Some of the things would be, 'let's get some cars into the government fleet," Mr Peters said.
"Another thing that they could look at would be incentives to use congestion-free lanes. Now this is something that's happened overseas, people have bought EVs on the back of the fact that they can actually drive down a lane that no one else is using."