For the first time in many decades, urban transportation is in the midst of rapid change. For many, change can’t come fast enough.

Today’s transportation system, both in the U.S. and increasingly around the world, places personal car ownership at its core. That comes at a high cost. Cities spend billions of dollars on parking spaces, using valuable resources and real estate that could be transformed into housing or office space. In the U.S., we waste seven billion hours a year sitting in traffic. Not only does traffic affect productivity, but also emissions from idling cars make up more than 20% of our total carbon footprint.

This is the transportation landscape in which ride-sharing services like Uber were created, and in just a few years, we’ve begun to witness the transformative impact that ride-sharing can have. By turning personal cars into shared vehicles, services like ours have been able to bring on-demand transportation and an alternative to car ownership to new neighborhoods and populations in large cities, and, increasingly, to smaller towns and even rural areas.

And we’re just getting started. Today, ride-sharing accounts for less than 1% of miles driven globally. By 2030, Morgan Stanley estimates, that number could rise to more than 25%.

Even while these changes take place, others are coming. It’s no secret that self-driving cars will become a reality sooner than anyone may have expected. It’s still very early days, so we expect that the transition will require a hybrid approach for some time. Since self-driving cars will initially be unable to travel along certain tricky routes, handle difficult weather conditions or meet periods of peak demand, we expect that we’ll see a mix of human-driven vehicles alongside self-driving ones for years to come.


But we also know that research has shown that self-driving technology could drastically improve the way we get around, while improving road safety. However, for their benefits to be widely distributed, we strongly believe that self-driving cars must be shared, rather than individually owned and operated. A system of individually owned, self-driving vehicles could replicate—and possibly even exacerbate—our existing transportation challenges.

Ultimately, we understand the goal of reducing private car ownership is one we share with cities across the globe. That’s one reason we work with partners in government around the world. Whether it’s connecting our service with vital mass-transit systems, partnering on deploying electric charging infrastructure or providing data on Uber trips to transportation planners, we’re excited by the steps we’ve already taken in this direction.

We know we can do more, and we will. Technology on its own is not a solution for urban problems—but done right, and in partnership with others, we believe shared mobility has the potential to contribute to a better world for all.

Mr. Khosrowshahi is chief executive officer of Uber Technologies Inc.