that it's got some urban dwellers wondering...

Why bother owning a car when you can easily get where you want at the press of a button?

It's an idea known as “mobility as a service”,

where travelers say goodbye to their own cars

and sign up instead for transportation-on-demand booked through their smartphones.

Imagine, for instance, a commuting plan that charges by the mile or through a monthly fee, like Netflix.

The demise of car ownership, at least in the world's growing urban centers,

is a prospect that the world's automakers are getting ready for.

But it's not going to happen right away.

A major switch to subscription transportation requires two things to fall into place.

The first is already well under way:

the explosion of ride-hailing apps like Lyft, Grab and Careem.

The second part isn't quite there yet.

That's driverless cars.

Removing the human from behind the wheel slashes the cost of a taxi ride.

That will make mobility as a service so cheap in many places,

it won't make financial sense to own a car anymore.

A typical ride today costs $2 to $3 a mile,

but a robo-taxi is projected to cost as little as 70 cents per mile.

Tesla chief executive, Elon Musk reckons

he can lower that to 18 cents a mile.

That will turbo-charge demand for mobility as a service,

which is destined to become a $10 trillion business, according to Ford Motor Company.

That's why tech giants like Google and Apple are developing their own self-driving systems

to take on the world's leading automakers, including Volkswagen, General Motors, Ford and Toyota.

Eventually, a single smartphone app could connect us to a web of options:

robo-taxis, self-driving shuttles, subways, e-bikes and electric scooters --

that will whisk us through congested megacities,

where two-thirds of the global population is projected to live by mid-century.

Someday, urban dwellers may have to spend a day in the country

to catch a glimpse of that 20th Century show pony known as a private car.