Given most vehicles sit idle for the majority of the day, why not share a car among those who need it at different times?
Transport experts estimate cars are parked for over 90 per cent of the time. And in a world where urban space is increasingly at a premium, the cost of parking a car overnight or while working during the day is difficult to justify.
Founded a decade ago by former Auckland councillor Victoria Carter, alongside JUCY Rentals, Cityhop now has more than 60 cars placed in Cityhop-owned parks around Auckland and Wellington.
Their 2000 members subscribe to vehicle "plans" using a model similar to that of mobile phone network plans.
Carter says the move from councillor to entrepreneur was driven by a desire to "start a business that fitted with my social and environmental goals.
"Cityhop is disrupting the private vehicle ownership market and is offering consumers and firms a flexible, affordable and sustainable alternative."
Arguably a fork has been reached in the shareable transport road. The question is: do we replace our cars with on-demand taxis like Uber or Zoomy, or borrow the cars from companies like Cityhop and drive ourselves?
Uber is certainly the more well-known name, owing to its rapid global rise and displacement of traditional taxi services.
But Cityhop predates the multinational taxi app and has local origins. Carter says it is a false dichotomy, "Our competition is people who own a car and don't want to consider the cost of car ownership."
Convincing those people of the benefits of car-sharing, she says, is the key to CityHop's success.
The company is currently registering more than 60 new drivers each month. As membership grows, the fleet can expand, offering more flexibility and availability to its members - a virtuous, self-reinforcing cycle.
The company offers three different plans. They include a subscription fee (from $29 per year to $10 per month), an hourly rate (from $9.50/hour to $13/hour), a distance fee (40 cents per kilometre across all plans), or a flat maximum daily rate for those who rack up more significant distances (between $65/day and $75/day).
Once signed up, members book a car for their preferred number of hours online. Cars are unlocked by holding a membership card on the windscreen, and users can then drive the car as much as they please during their booked period, before returning to one of the company's designated parking spots across the city.
Though the fees are nothing to be sniffed at, car-sharing proponents point to the costs of individual ownership as being far higher. "When most people look at what their car actually costs them, they are a bit surprised," says Carter.
And the spillover benefits for cities such as Auckland are arguably even greater.
"Every car-share car takes 13-15 privately owned cars off the road," explains Carter. "If we lined up all the cars removed based on our current fleet, there would be empty car parks from the Ferry Building to K Rd! So we are a significant congestion buster."
There are also environmental benefits, with claims that each Cityhop vehicle contributes to 37.83 tonnes of CO2 not being released into the air per year.
A quarter of the company's cars are hybrids, and a joint venture with Mercury Energy this year saw the first electric vehicles join the fleet.
From an urban planning perspective, Carter claims Cityhop's existing network releases an estimated 2.5km of road space and kerb space.
The key to further proliferation of car-sharing seems to be securing more car-share car parks, expanding the fleet, and thereby attracting more members.
The concept is taking off. Apartment buildings such as The Daisy in Mt Eden have adopted CityHop cars, and businesses are also placing them outside their offices to provide a transport option for employees. Those complement a variety of street parks around the CBD and city fringe.
At this stage, Cityhop is a "stepping stone" for many of its customers - not yet getting rid of cars altogether, but decreasing the number they might have previously shared as a couple or a family.
"A lot of these people are downsizing from homes where they might have had three or four car parks, and now they've gone down to one or two," says Carter. "And most people's second or third car is not well-used."
"Our focus is helping people get out of car ownership and reducing the number of cars they own," she says. The achievement of this vision, and delivering the associated urban development benefits will surely benefit from ongoing support from local government.
"It feels like it has taken a really long time to get Auckland Transport on board," admits Carter.
"They're now on board and they really get it; they really can see the difference that we're making."
Sydney is already showing the way when it comes to local government championing of shareable transport.
Clover Moore, the Lord Mayor of the City of Sydney, is a self-professed advocate of car-sharing and has encouraged a burgeoning of the industry in the city.
The City of Sydney reports some 31,000 business and resident car sharing members as of May 2016.
The City of Sydney has the lowest rate of household car ownership in metropolitan Sydney - about 35 per cent of city households do not own a car, compared to approximately 12 per cent of households across greater Sydney.
A study commissioned by the International Car Sharing Association estimated the total net benefit of the car-sharing network to the city as $48 million per annum in 2016, with a return of $6.16 for every $1 invested by local government. Other estimates suggest the community benefits outweigh the costs by a factor of 19.
Carter says both businesses and council can take the lead by encouraging employees to utilise car-sharing services. Statutory requirements for new buildings to include car-sharing spaces within car parks might also be encouraged.
It might be thought that if councils discovered a "magic potion that catalysed mode shift, reduced pollution, reduced the cost of housing and made congestion (both traffic and parking) disappear, they would be united in their determination to sprinkle as much of this magic potion as possible across their municipalities", the Sydney report concluded.
Auckland urbanites may well notice more of that magic potion scattered about the city over the coming year and beyond if recent trends continue.
