Can automated, shared, electric vehicles cut energy use, greenhouse gas emissions and costs?

October 23, 2015

By Mark Golden

SACRAMENTO, CA−In the opening of the 1960s cartoon “The Jetsons,” George does not do much driving as the family flies around in their car. They also seem to live really far from their schools, shopping and work.

That illustrates one problem with the view of a transportation future in which consumers generally do not own cars and instead rely on driverless, electric cars operated by Uber-like companies. Such a future and even pieces of it not far off are frequently described as part of the solution to climate change and other problems. But several panels at the annual Behavior, Energy & Climate Change conference called that vision into question.

800px-Jurvetson_Google_driverless_car_trimmed“There is the utopian vision where automation saves the world, but there is also a dystopian view. The disagreement is not about technology, but about people,” said Austin Brown, senior policy analyst for energy research and development in the U.S. President’s Office of Science & Technology Policy.

Will super-convenient commutes lead to greater urban sprawl for the economically well off? Mobility services could make transportation affordable to the millions of American poor now underserved by public transit. That would be a good outcome in many ways, but would it, too, increase energy use and greenhouse gas emissions? If people are saving money compared with car ownership, will they order a car just big enough for the trip or a big mobile lounge? Will they have the car operate efficiently or go for speed?

“There is such big variation in the potential outcomes. In total, automation could reduce energy use by 90 percent or increase it by 200 percent,” Brown said at BECC. “The defining factor that will determine the size of the effect in most cases is human behavior.”

In a separate panel at BECC, Reuben Sarkar, deputy assistant secretary for transportation at the U.S. Department of Energy provided a case study on this effect in his own behavior. Sarkar moved to Washington, DC a year and a half ago and decided recently to go carless—a big decision for the former car designer at GM—because he was almost never using his car. Ironically, the extra money he has from returning his car is resulting in more time spent in cars, like Ubers, and less time on public transit.”

“I’m guessing about 20 percent more car riding now than when I owned a car,” he told BECC’s closing session. “Given myriad options, the DOE has to get better understanding of decision making. I make the decision of how to get to work when I walk out the door. I’m checking surge pricing, the weather, my schedule, etc.. How can we motivate low-carbon multimodal transportation systems to achieve climate and energy targets?”

Automated vehicles could also safely drive much closer together on highways than human-driven cars. This “platooning,” which is the subject of much research and development already, could improve mileage and reduce emissions, congestion and cost.

“But it’s not a good deal for the lead vehicle, which may hold platooning back,” said Bill Van Amburg, senior vice president of CalStart, an organization that supports a high-tech, clean transportation industry.

A tax on carbon dioxide emissions should help rein in the worst potential effects of automation, which is likely to arrive before electricity is predominantly made from renewable sources, said Van Amburg. Culturally, the key will be to make some things “cool” that currently are not to most Americans, like fuel-efficient cars, living near work and buying local products.

Rideshare services

So far, the ability of rideshare companies like Uber and Lyft to lower energy use and emissions has been limited. Both companies say their long-term goal is to reach a critical mass of drivers and riders in a city, so that they mostly pair up strangers with nearly identical commutes. That would be a clear environmental boost, but representatives of Uber and Lyft speaking on another BECC panel could not say what percentage of their rides today fit that model of drivers on their way to a job or home. In aggressive marketing, meanwhile, Lyft promises drivers at least $1,000 weekly income, which would require driving as a full-time job.

Unless and until the critical mass forms, the services–just like taxies–can cut only the energy and emissions used in making automobiles, not operating them. Reducing embedded emissions is a modest environmental prospect to begin with and further depends on how much rideshare services convince customers to not own cars.

However, the environmental benefits appear to be improving in the Lyft and Uber’s biggest markets with their increasingly popular pooling services. This spring Lyft announced that pooling accounts for 50 percent of its rides in San Francisco and 30 percent in New York City. That clearly is taking cars off the road.

On the same panel, executives with Google and startup Bridj made strong environmental cases for their buses and vans. Some 30 percent of Google’s employees on the San Francisco peninsula take Google buses to work, which helps the company meet its carbon commitments, boost employee productivity and cut parking costs.

Bridj is looking to get public transit systems to use Bridj’s vans and software to supply transportationin low-density populations that is more convenient for customers and less costly than operating buses on the outskirts of the system.

“We will almost never pick you up or drop you off exactly where you want, but instead within a five- to seven-minute walk,” said Matt George, the company’s founder and chief executive. As a result, most of the seats in most of Bridj’s vansin Washington, DC and Boston are filled most of the time, which reduces costs and environmental impact compared with nearly empty buses or cars.

Bridj also addresses issues that Uber and Lyft cannot, George said. “98 percent of people in big cities are not affected by Uber and Lyft. We ask the hard questions about social equity, true access and safety,” said George. “Any option that gets more than three people in a safe vehicle that’s driven by a professional driver is a good thing.”

How to promote biking

Maybe the best solution is to avoid cars and buses altogether. As noted in another discussion at BECC, people who use public transportation generally hate their commute, as do people who drive. The only people who like their commute are people who bike or walk to work.

University of Toronto School of the Environment researcher Beth Savan has studied the characteristics that make certain neighborhoods good targets for the promotion of biking to work.

“Just putting in bike lanes doesn’t do it. You need a relatively flat environment, commutes of five kilometers (3.1 miles) or less, a lot of and cycling is possible on trails, separate lanes or streets with slow traffic,” Savan said. “About two-thirds of cyclists are male. Most are 25 to 55 years old, so don’t target too old or too young.”

Converting drivers into bikers, like changing social norms generally, must be nudged along slowly until a critical mass forms, but then things can change quickly. Programs in neighborhoods that meet Savan’s criteria as good targets still need visible bikers in the area and the involvement of community groups to succeed.

Similarly, research by Matt Biggar, a doctoral candidate at Stanford’s School of Education, found that university employees who chose an alternative to driving alone–biking, walking, public transit or carpooling–had many friends and close coworkers choosing alternate transportation, too. Employees who drove solo reported that everyone in their department drives, and they almost always had a negative past experience with alternative transportation.

“Across all cases, the attitudes of close social ties and past experiences together explained mode choice,” Biggar said of his small study. “In the Bay Area, we have the built environment for alternative transportation, but we require much more work on social and subjective factors.”

Behavior, Energy & Climate Change is an international conference focused on understanding the behavior and decision-making of individuals and organizations, and using that knowledge to help accelerate the transition to an energy-efficient and low-carbon future. Stanford University’s Precourt Energy Efficiency Center, the Berkeley Energy & Climate Institute, and the American Council for an Energy-Efficient Economy organize BECC.

(Mark Golden works in communications at the Precourt Energy Efficiency Center at Stanford University.)


Media Contact: Mark Golden, (650) 724-1629,