woman on street flagging down Uber

Ride-hailing from services like Uber and Lyft may be convenient for people looking to get from Point A to Point B — but they are not the ideal transportation solution. Turns out that these services are worse, in terms of carbon emissions and urban traffic congestion, than taxis or personally-owned vehicles, according to a report from the Union of Concerned Scientists (UCS), a nonprofit advocacy group.

The UCS examined the impact on seven U.S. cities — Boston, Chicago, Los Angeles, New York, San Francisco, Seattle, and Washington, D.C. — using a mix of public data plus other research findings.

Here are some highlights from their report, including what local travelers, ride-hail drivers, transit providers, and governments can do to minimize per-trip carbon-emissions impact.

Ride-Hailing: Small But Growing, and Already Eco-Impacting

Ride-hailing companies, according to the UCS report, “today result in an estimated 69 percent more climate pollution on average than the trips they displace.”

There are two main reasons for this:

  • Ride-hailing vehicles have a higher emissions-per-mile impact than other public and private local transportation options like ride-sharing, buses, trolleys, subways and light-rail, bicycling, and, of course, walking.
  • Ride-hailing vehicles have a greater tendency than personal vehicles or traditional taxis to be on the road without passengers, such as in between drop-offs and pickups — up to 40 percent of their miles. They are also more likely sit idling when waiting for riders.

The Per-Mile Carbon Footprint of Travel Choices

“Transportation is the largest source of emissions in the United States, and the largest part of that comes from people driving,” says Jeremy I. Martin, director of Fuels Policy and senior scientist in the Union of Concerned Scientists’ Clean Transportation Program.

According to Martin, “The average person’s daily driving — 27 miles — is responsible for about 12 kilograms of carbon emissions. If you replace a 10-mile single passenger ride-hailing trip with a pooled ride, you can cut emissions by more than 2 kilograms. If you take a pooled ride to transit, you can cut emissions by almost 5 kilograms. And since transportation is the largest source of U.S. carbon emissions, these savings can add up.”

How much of that daily driving is from ride-hailing?

According to MAPC’s 2018 report, Share of Choices, in 2017, ride-hailing accounted for about 1.3 percent of all trips in the MAPC region. In 2018, MAPC estimated that grew to 1.7 percent.

“If growth in ride-hailing emissions continues unchecked, it will make it very difficult for the state to meet its emissions reduction targets,” cautions MAPC in their July 2019 report on ride-hailing in Massachusetts.

What We Can Do

The “what can be done” options are in a range from readily doable by individual and group riders, to will-need-time-and-effort changes by drivers, providers, cities, and governments. Here’s a quick overview of UCS’s advice:

  • People: Try to walk, bicycle, or use public transit where possible; try to use vehicle rides, single or shared, to “bridge” to and from public transit. Use electric vehicles rather than gas-burners when possible. Similarly, ride-share rather than go it alone, when possible, and request electric hailed vehicles. Also, suggests the USC, write to Lyft and Uber urging them to promote pooled, electric hailed-vehicles.
  • Ride-hailing providers: Shift your vehicles (your drivers’ vehicles) to electric, which reduces emissions by about 50 percent, according to UCS. Promote (and facilitate) ride-sharing. The combination — “electric pooling” — can reduce emissions impact by nearly 70 percent.
  • Employers and governments: Create and promote pollution-reducing transit policies and programs, such as monetary incentives to move to electric vehicles and to improve public transit. And, of course, publicize the carbon-footprint differences and what each ride-choice can do.

And it wouldn’t hurt to subsidize public transit — reduce or even eliminate fares — to encourage ridership.

To be fair, when done carbon-efficiently, UCS’ report acknowledges, ride-hailing can make eco-sense. And there will be occasions where ride-hailing — even if the ride is unshared and non-electric — is your best choice.

While UCS’s report focused on ride-hailing, the report notes, “many of its findings and recommendations apply to taxis as well.”

By Daniel Dern

Daniel P. Dern is a freelance technology and business writer, primarily about computer/Internet technology, including related environmental aspects of heat/cooling/power, manufacturing, and "end-of-life" recycling. His articles have appeared in the Boston Globe, Byte, ComputerWorld, IEEE Spectrum, and TechTarget. He also writes science fiction and kids stories (some are both), doing his best not to recycle plotlines.