Investing in transportation infrastructure, which Gov. Dannel P. Malloy says Connecticut must make a priority, cannot alone address the problem of drivers spending hours sitting in traffic on their way to and from work every weekday. Congestion is not only a fact of life in major cities all around the world, it also increases pollution. Today 22 percent of all CO2 emissions globally come from transportation.

Fixing these problems is now a priority for most city governments.

The problem is not so much cars themselves — it’s how we use them: individually. Next time you stop at a red light, look to your right or left. Chances are those cars will have just one person in them: the driver.

For many individuals car ownership is a necessity, not a luxury. It’s a form of “mobility insurance” — people own cars to ensure that they can reliably get where they need to go, whether that’s work, school or to visit family. This is especially true in communities like southeastern Connecticut that are not well-served by mass transit.

The good news is that technology — on-demand ridesharing apps like Uber — can help solve these problems. The ability to push a button and get a ride is becoming a reliable, convenient and affordable alternative to individual car ownership. Uber has proven that ridesharing can serve every corner of a city — including the parts that other means of transportation cannot reach. In Connecticut, you can push a button in the Uber app and the average ride is less than 5 minutes away.

On-demand, ridesharing apps complement existing public transportation systems, at no extra cost to the taxpayer. If your subway or bus doesn’t get you all the way home, Uber will take you that last few miles. In London, for example, the Underground launched an all-night service to help people get home in the early hours. Almost immediately, Uber saw a decline in pickups in the city center but an increase at train stations in the suburbs. In other words, Londoners are taking the train to get out of the city center — and taking Uber to get the last few miles home.

Affordability is crucial as well. On-demand ridesharing apps like Uber will only replace individual car ownership if they can serve people at every income level. The obvious solution is sharing. By getting multiple people into one car, they can split the cost. Of course, policymakers have been talking about carpooling for years but the idea never really took off, mostly because it was just too hard — until now.

A few years ago we had a breakthrough when our engineers noticed that Uber had a lot of duplicate rides, people going to the same place at the same time. They asked the question: could we use technology to match these people up in real time, making it one ride instead of two, or even three? The real question was, “would people choose to carpool with strangers for a discount?”

The answer was a resounding yes. Because sharing isn’t the issue: it’s price and convenience that matter most to people. In cities where POOL is available, it accounts for 20 percent of Uber trips.

While the progress we’ve made in the last five years is exciting, self-driving cars will enable us to fast forward to this future. A recent Organization for Economic Co-operation and Development study found that a shared, self-driving service could reduce the number of cars on the road by 90 percent or more. For our cities, the change would be dramatic, with so much of the stress and cost gone from city life.

A few weeks ago, I discussed these same ideas as part of a keynote address at the Northeast Autonomous Vehicle Summit in Mystic. Hosted by the University of Connecticut’s School of Engineering and Connecticut Transportation Institute, this event brought together the Federal Highway Administration and the Connecticut Department of Transportation to discuss the vast, positive changes that self-driving cars can bring to our communities.

Places that embrace ridesharing now will have a natural advantage when it comes to self-driving. We need to get people used to leaving their cars at home sooner rather than later; or better still, not buy one at all. Given that self-driving cars will initially be expensive, sharing them across multiple passengers will help reduce the cost of rides, ensuring the technology is adopted more quickly.

This is our hope for the future: that we can turn every journey into a shared journey using a combination of ridesharing and public transportation. And that people will use these services not through coercion but choice, because sharing will be a cheaper and more convenient alternative to individual car ownership.

Jason Post is Uber’s Director of Policy & Communications for the Northeastern United States.