Study: E-Scooters Slash Emissions and Reduce Congestion

Love'em or hate'em, e-scooters are good for the environment.

E-scooters for rent
E-scooters for rent.

Garrett Aitken/ Getty Images

Shared e-scooters are controversial, as they are reviled by many who complain they are littering sidewalks or mowing down pedestrians. Plus, some studies claim they replace walking trips, not driving trips. But two new studies indicate e-scooters actually reduce car travel trips and emissions.

This is a bit of rare good news in the e-scooter world where many companies are losing money. Bird recently announced it had not been accurate in its bookkeeping. According to a statement: "If the company is unable to raise additional capital or generate cash flows necessary to expand its operations and invest in continued innovation, it may not be able to compete successfully and may need to scale back or discontinue certain or all of its operations in order to reduce costs or seek bankruptcy protection."

Lime is doing better. Its chief policy offer told Bloomberg, “We are definitely at a crossroads and the industry is going to look quite different in the next six months. Scale is important in this industry. Smaller companies will struggle.”

This is a shame because the scooters are better than they used to be: they are geofenced, have speed restrictions, and cannot be carelessly parked without it costing the rider a lot of money. The real problem is a lack of safe infrastructure; people ride them on sidewalks when they are afraid to ride them on roads. And when you look at the numbers, dockless cars are a bigger problem on sidewalks than dockless scooters. Yet people keep trying to ban the e-scooters as being the real danger here.

Atlanta scooter sticker
Seen while e-scootering in Atlanta.

Lloyd Alter

One of the two studies of e-scooters came about because of a ban in Atlanta, which shut down all e-scooters between 9 pm and 4 am after e-scooter riders were killed by drivers of cars. According to the Georgia Tech statement, asking "Do electric scooters reduce car use?," the answer is definitive. The study’s principal investigator, Omar Asensio of Georgia Tech's data science and policy lab explained:

“I thought, okay, that's interesting because now we have near-perfect behavioral compliance in response to a policy intervention, which turns out to be extremely rare. All of a sudden, if you're without the use of the scooter, what do you do? This created a great natural experiment, to be able to precisely measure the traffic times before and after this policy intervention and in doing so, test behavioral theories of mode substitution.”

The experiment showed that the average commute times increased by about 10%. They also estimated e-scooters, e-bikes, and other micromobility options can save an average of 17.4% in travel time for drivers nationally.

They conclude in the study, as we do on Treehugger, that we have to make our cities safer for scooters and the people around them.

"To accelerate the adoption of micromobility and achieve its associated sustainability benefits, we argue that cities will need to make additional investments in both physical and digital infrastructure. For physical infrastructure, land use and space allocation will require longer-term planning such as converting lanes usually reserved for cars into bike lanes that can be used for micromobility."

Transportation writer Aaron Gordon is not impressed with the study. "Personally, I think it’s silly to ban e-scooters because drivers keep hitting the people on them," he wrote for VICE. "This is a problem with cars and road design, not the scooters." But he also noted that the one or two-minute delays suffered by drivers are not big enough to make a difference.

Yet in the city of Toronto where I live, bike lanes were torn up because they might make someone five minutes later for dinner, and a billion dollars are being spent on rebuilding an elevated expressway that saves three minutes of driving time. When it comes to drivers, two minutes are sacred.

Grams of CO2 per km traveled
Grams of CO2 emitted per km traveled from LCA.

Konstantin Krauss et al, Fraunhofer Institute

The other study, prepared by analysts at Germany's Fraunhofer Institute for Systems and Innovation Research, is questioned by Kea Wilson of Streetsblog because it was commissioned by Lime. But the study is still very interesting, as it did full lifecycle analyses of different modes of transport. It found that the new generation 4 scooters, which have a long lifecycle, have lower emissions per kilometer traveled than anything but a private bike or e-bike.

"The largest shift effects are from walking, public transit, ride-hailing, and private vehicles to shared micromobility. In all six cities studied, shared micromobility shows emission reduction compared to the modes replaced. This effect is more positive for shared e-scooters than shared e-bikes, due to differences in their relative embedded carbon and life spans ... Our results also point to the importance of cities implementing solutions like protected bike lanes or travel cost and time increases for individual motorized transport."

So there appears to be a consensus among those who don't have visceral hate of e-scooters: They can take cars off the road, which may reduce travel time for those who are driving, and they reduce congestion and emissions.

But everyone, from the studies to the critics, agrees they need infrastructure like protected mobility lanes. As for Bird, I hope they can clean up their books and survive—they were my favorite ride.

View Article Sources
  1. Weschke, Jan, et al. “Mode Shift, Motivational Reasons, and Impact on Emissions of Shared e-Scooter Usage.” Transportation Research Part D: Transport and Environment, vol. 112, 2022, p. 103468., doi:10.1016/j.trd.2022.103468

  2. Asensio, Omar Isaac, et al. “Impacts of Micromobility on Car Displacement with Evidence from a Natural Experiment and Geofencing Policy.” Nature Energy, vol. 7, no. 11, 2022, pp. 1100–1108., doi:10.1038/s41560-022-01135-1