The Surprising Impacts Of Ridesharing: Environment, Congestion, And Beyond

In 2015, then-CEO of Uber Travis Kalanick gave a special address commemorating five years since the company’s inception. In that address, he delivered the following optimistic ideas:

“A city that welcomes Uber onto its roads will be a city where people spend less time stuck in traffic or looking for a parking space; a city where people will spend less of their income on cars or commutes. … It will be a cleaner city, where fewer cars on the road will mean less carbon pollution – especially since more and more Uber vehicles are low-emission hybrid vehicles.”

Transportation network companies (TNCs), commonly called ridesharing companies, were often touted as a step toward a greener future. At face value, it makes sense. Fewer people will need to drive or even own cars, so that should decrease overall time on the road and emissions, right? Unfortunately, the data doesn’t quite support that vision.

What The Data Says About Ridesharing’s Impact On Pollution

The Union of Concerned Scientists (UCS) out of Cambridge, Mass. published research on ridesharing’s effects on pollution and congestion in a 2020 study called Ride Hailing’s Climate Risks. According to the study, ridesharing trips with gas vehicles produce an average of 69 percent more pollution than the trips they displace.

This is due to two main reasons. First, ridesharing creates deadhead miles, or miles where drivers aren’t transporting passengers but are waiting around for trips or traveling to a passenger. The UCS estimates that deadhead miles can account for about a third to half of ridesharing mileage – or more. Second, ridesharing displaces some greener transportation alternatives. Without Uber or Lyft as an option, some riders would bike, walk, take a scooter, or get on mass transit instead of driving a personal vehicle.

The UCS found that single-customer rideshare trips with gas vehicles produce 47 percent more emissions than private car trips. But when combined with the greener transportation options they displace, rideshare trips produce about 69 percent more pollution.

Our team spoke with Don Anair, research director for the UCS Clean Transportation Program and an author of the study cited above. Anair summed up the study in this way:

“Ridesharing is so convenient that most of us don’t think about what happens behind the scenes. People might assume one rideshare trip displaces just one vehicle trip, but it often displaces other greener modes of transportation as well. Rideshare drivers also spend a lot of time on the road without carrying any passengers. The biggest takeaway of this study is that rideshare trips cause 69 percent more emissions than the trips they displace.”

What About Electric Rideshare Vehicles?

There is a silver lining to the UCS study. According to Anair, “If all rideshare trips were to take place in EVs, we’d cut emissions in half.” The researchers found that single-customer rideshare trips in electric vehicles reduced emissions by 53 percent compared to private gas vehicles. And when two customers pooled their ridesharing trip, it reduced emissions by 68 percent.

Another selling point of ridesharing is that it could require fewer people to drive themselves. It could even lead to less people owning vehicles, which should lead to decreased congestion. So have these promises panned out?

Researchers at Tongji University, MIT, and the Future Urban Mobility Interdisciplinary Research Group at Singapore-MIT Alliance for Research and Technology dove into the issues headfirst and published their findings in 2021. The researchers looked at monthly federal traffic data for 44 metropolitan areas and compared congestion statistics before and after TNCs entered the market. According to Impacts of Transportation Network Companies on Urban Mobility, transportation network companies increased congestion duration by 4.5 percent and intensity by about 1 percent. 

Some cities have changed or introduced policies to account for increased congestion. For example, Chicago modified its ground transportation tax in 2020 to encourage other forms of transportation during peak hours. There is now a downtown zone surcharge on trips that start or end downtown during weekday peak hours. The surcharge is higher for single-occupant rides.

The city of Chicago doesn’t say exactly how much TNCs have influenced congestion, but it does say that single riders account for 77 percent of rides during peak times.

Did Chicago’s Downtown Rideshare Tax Work?

The good news is that Chicago’s tax seems to have reduced single-rider trips and opened up a little more space on the roads downtown. Researchers at MIT and Xiamen University (including two for the paper referenced above) took a look at Chicago’s congestion data in 2023 to analyze the effects of the tax.

They found the policy decreased downtown rideshare trips by 7.1 percent overall. Single-occupant trips decreased by 11 percent while shared trips increased by 16.4 percent. That was exactly what the city set out to do.

The Union of Concerned Scientists cited Chicago’s downtown rideshare tax as an example to follow in its 2020 study. Speaking about the updated data in 2023, Anair said, “Chicago’s example shows that public policy can have a positive impact on ridesharing. This example can encourage other cities to steer ridesharing from being business-centered to being centered on the community as a whole.”

Pooled Services Still Aren’t The First Choice

If everyone would use pooled ridesharing services, there would be fewer cars on the road and congestion would decrease. Yet while many people may be comfortable getting into an Uber with others they know and carpooling to a single place, how do riders feel about pooled rides with strangers?

UberX Share is the resurrection of Uber Pool, which died out during COVID-19. UberX Share and Lyft Shared both match you with riders going in the same general direction. You get a break on the price but it adds time to the overall trip. Uber and Lyft do what they can to promote pooled rides, but the programs are only available in certain cities. 

If a rider is right on time to catch an Uber to work, will they want to take a gamble on saving a few bucks with UberX Share to pick up a random person while increasing transit time? Probably not. 

The California Air Resource Board (CARB) studied pooled vs. non-pooled rides through rideshare driver diagnostic vehicle data. The data included 31 drivers who completed 2,754 trips in the survey timeframe. CARB found 336 of these trips were pooled, while 2,418 were not. In other words, pooled trips accounted for about 12 percent of overall trips in the survey.

It may take more drastic changes, like Chicago’s downtown rideshare tax, to encourage more people to take a car with a stranger. But do companies have enough incentive to make changes for the better? “Companies are motivated to give rides to as many customers as possible and to keep growing, so public policy is important to steer the industry and get the best outcome for everyone,” said UCS’s Anair. “Municipalities need to prioritize people, not the number of trips.”

If you’ve never driven for Uber or Lyft, you might be surprised to find out that regular car insurance doesn’t cover 100 percent of the time a rideshare driver is on the road. If you drive for one of these companies, you should definitely take a look at your current coverage to see if you’re protected.

Rideshare companies provide insurance while a driver is transporting a person. Standard car insurance plans provide coverage when a driver is off the clock. But there’s a gap in coverage when a driver is signed into an app and waiting to pick up a passenger.

Uber and Lyft offer basic liability insurance when drivers are waiting for a job. However, this only covers low levels of bodily injury and property damage. It doesn’t cover damage to your vehicle or medical coverage for yourself. To get full coverage during this time, you’ll have to add a rideshare endorsement from your car insurance company. Most drivers can get this for under $30 per month.

The researchers at MIT and Tongji University also considered how rideshare companies impact public transit usage in their 2020 paper. They found that public transit ridership decreased by an average of 8.9 percent in 174 metro areas that had regular ridership records.

Uber and Lyft can do things public transit can’t, like pick you up at your door or get you home after hours. With ridesharing, you only have to interact with one stranger, not wait in line and deal with a crowd of them. It makes sense that, given the opportunity, a good portion of the population would defect from public transit options in favor of hailing a car with a simple app.

Are Fewer People Owning Cars Because Of Uber?

In the same paper, the researchers compared car ownership before and after the introduction of TNC companies in the 174 metropolitan areas, and found that it didn’t change much overall. However, they took a closer look at the 10 metro areas with the best transit systems and found that vehicle ownership decreased by 1 percent in these locations.

That means some people may choose to ditch their cars altogether in areas that already have strong transit networks. But in areas with average or below-average transit networks, vehicle ownership didn’t really change.

It’s been eight years since Kalanik’s remarks on the future of Uber in cities. To Uber’s credit, it has been working on that vision. The company teamed up with BP Pulse in 2023 with the goal of becoming a zero-tailpipe emissions company in the U.S., Canada, and Europe by 2030 – and the rest of the world by 2040. By 2040, Uber’s goal is to have all rides on the platform completed with electric vehicles, public transit, or micro-mobility options like scooters and bikes.

Uber is providing incentives for drivers to go electric. For example, the Zero Emissions incentive gives fully-electric car drivers an extra $1 per eligible trip through the end of 2023. Uber drivers can also get charging station discounts and deals on electric vehicle (EV) rentals and purchases.

Uber is also working on the public transit issue with Uber Transit. The option, which is available in select cities right now, lets users plan trips and pay for tickets in the app. Uber also works with paratransit agencies to help people call rides and pay for fares. Paratransit services are community transport lines that go beyond fixed routes, like the Dallas Area Rapid Transit (DART) service.

Considering recent developments like these, Don Anair said, “Corporate values and commitments are good, but companies need to make it happen. Uber and Lyft encouraging more electric cars is great, but the companies should also be prepared to support public policies that regulate their operations.”

Supporting transit agencies and encouraging electric vehicles are steps in the right direction. Perhaps gas-vehicle ridesharing was a necessary evil to get to a greener future of convenient transportation. But it doesn’t seem like ridesharing will deliver on its promise of less congestion. Despite the name, ridesharing is a convenience many of us will continue to enjoy alone – and drivers will log double the miles to shuttle us around town.