The two top ridesharing companies in the world, Uber and Lyft, have pledged to transition to fully electric vehicles in the US, Canada and Europe by 2030. The move is hailed for its impact on reducing greenhouse gas emissions, but a new study shows that it could bring some downsides.
Researchers at Carnegie Mellon University and the University of Michigan have found that all-electric ride-hailing fleets cut greenhouse gas emissions, but increase air pollution and traffic problems. Overall, making all rideshare vehicles electric would bring a societal benefit of only 3 percent per trip on average, according to the study published in the journal Environmental Science & Technology.
The past few years have seen a steep rise the rideshare sector, as millennials move away from owning cars and there is more demand for on-call transportation services. Ride-hailing companies, led by Uber and Lyft, have at the same time been increasing their hybrid and electric vehicle offerings for customers.
EVs make sense for rideshares since these fleets operate in urban areas and vehicles don’t have to travel long distances at a time. They are also cheaper to run and maintain than gasoline vehicles, and offer a smoother, quieter ride experience.
But what real-world societal and environmental benefits would electric fleets promise? The CMU and Michigan researchers conducted life-cycle comparisons based on real-world rideshare data to find out.
They used data collected in the Chicago area from 2019 to 2022. Chicago is one of the largest ridesharing markets in the country, with an average of about 300,000 daily trips prior to the COVID-19 pandemic. They used a model that combined data from over a million Uber and Lyft trips taken on weekdays, weekends, and during different seasons with detailed geospatial vehicle routing data to analyze the costs of ridesharing services in terms of greenhouse gas emissions, traffic costs, and air pollution. They compared these results for a gasoline fleet and a battery-electric fleet.
Rideshare vehicles drive more miles every year than personal vehicles, the researchers write, “which means that electrifying these vehicles could have greater societal benefits.”
Indeed, their analysis showed that electrified fleets had 40–45 percent lower greenhouse gas costs per trip compared to the gasoline-powered vehicles. But the EVs also created slightly higher air pollution—sulfur dioxide, nitrogen oxides, and particulate matter—because recharging them relied on power from local power plants and also created more fine ground-level particles from tire and brake dust.
The simulations showed that EVs had to drive farther and more frequently without passengers since they have to travel to recharge more often than gasoline vehicles have to refuel, and there are fewer charging stations than gas stations. The longer traveling distance meant they were involved in more traffic problems, including crashes, congestion and noise.
The study showed that higher air pollution would increase health impacts by an estimated 6–11 percent per trip on average. And the extra driving to and from charging stations would increase traffic-related harms by 2–3 percent per trip.
Full electrification of ridesharing fleets would reduce overall harms to society by about 3 percent per trip, the team found, which translates to about $1.5 million per year in savings for the city of Chicago. By contrast, tide-hailing generates an estimated $4–5 million in revenues per day in the city.
“Electrification is a small win for society,” said Parth Vaishnav, a professor in the school of environment and sustainability at Michigan, in a press release. “A bigger win would be to dramatically reduce our dependence on cars. Policies that decrease vehicle distance traveled through investments in public transit and infrastructure for biking and walking, or that reduce crash risk by improved vehicle safety, are critical.”
Source: Aniruddh Mohan et al. Life Cycle Air Pollution, Greenhouse Gas, and Traffic Externality Benefits and Costs of Electrifying Uber and Lyft. Environ. Sci. Technol. 2023.
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