Self-Driving Sustainability

By: James Raia

Heavy and erratic braking and aggressive acceleration are human driving traits. Robots brake more smoothly and are expected not to emphasize performance-oriented achievements, like testing the zero-to 60 miles per hour standard. 

A more even-keeled and even-heeled approach to driving, a robot's prerogative, reduces CO2 emissions. Businesses that supply their automotive fleets with autonomous vehicles rather than traditionally powered cars are at the forefront of sustainable practices.

It's a win-win scenario. The public will help save the environment as well as save money on fuel, electricity and other business and personal travel expenses. 

There's no denying, of course, reducing traffic congestion and correspondingly increasing the average safe driving speed would greatly reduce greenhouse gases.

A study at the University of California Transportation Center in Berkeley, Calif., revealed CO2 emissions could be reduced by more than 20 metric tons if collective traffic speed improved to 53 from 34 miles per hour. The chances of maintaining a consistently higher average rate of speeds are more conducive to robots' driving habits. 

A University of Michigan study examined the sustainable issue from another perspective. It stated the lifetime use of driving efficiencies from self-driving vehicles produced up to nine percent less greenhouse gas emissions compared to the traditionally driven vehicles. 

Gregory Keoleian, the study's co-author and director of the Center for Sustainable Systems at U-M's School for Environment and Sustainability, explained. 

"This study explored the tradeoffs between the increased environmental impacts from adding autonomous vehicle equipment with the expected gains in driving efficiency," he said. 

"Our findings highlight the need to focus on energy efficiency when designing autonomous vehicles so that the full environmental benefits of this emerging, transformative technology can be realized. We hope this work contributes to a more sustainable mobility ecosystem."

The study is a detailed assessment of the lifetime contributions of the sensing and computing subsystems in autonomous vehicles to energy use and associated greenhouse gas emissions. These vehicles, formally known as connected and automated vehicles or CAVs, often include multiple cameras, sonar, radar, LiDAR, a GPS navigation system, a computer and support structures.

The researchers examined two types of CAVs: Vehicles powered by internal combustion engines and battery-powered electric vehicles. Both types of vehicles were equipped with sensing and computer subsystems of three sizes (small, medium and large) to create six scenarios.

Life-cycle assessment methodology was then used to estimate lifetime energy use and greenhouse gas emissions for each scenario.

According to a recently published reported on a joint study by Natural Resources Defense Council and the BlueGreen Alliance, a consortium of labor unions and environmental advocates, stress the importance of self-driving vehicle sustainability. Economically, it's a must.

"Building clean vehicle technology directly supports 288,000 manufacturing and engineering jobs in the United States," the study's authors reported. "The jobs are at more than 1,200 factories and engineering facilities in 48 states.

The authors conducted the research to illustrate the industry's pursuit of greener parts and vehicles economically prudent, not just an environmental priority.

While arguably still ominous, sustainability in the autonomous vehicle industry will also be assisted by the interaction of vehicles on the road. How exactly self-driving cars will react with each other as traffic signs and lights, median and in other situations remains to be seen.  

The industry calls the interaction a "synchronous dance," according to the website The result: improved traffic flow and a dramatic reduction in accidents. 

Its greenhouse efficiency was studied by researchers from the Washington Auto Show. The group reported that if five percent of vehicles on the road were driverless, braking could be reduced by 99 parent and full consumption could be lower by as much as 40 percent.

Another collegiate study at MIT detailed aerodynamic efficiency of self-driving vehicles. The result contradicted the conventional wisdom of maintaining proper distances between vehicles on road. 

While a longer distance between vehicles would seemingly seem safer to avoid collisions, the concept of "synchronous-moving" or "highway platooning" could reduce fool cost by as much as 20 percent. It seems in the self-driving truck industry, more vehicles with shorter distances between them is better. The MIT report determined the more trucks in the platoon, the less drag is involved and therefore less drag translates improved fuel efficiency. 

Arguably the most convincing data stressing the importance of sustainability in the autonomous car industry research was released by the U.S. Department of Energy. It reports self-driving vehicles could reduce fuel savings of almost 90 percent if reliable policies are in place.

Conversely, if consistency in the self-driving industry isn't practiced, fuel consumption in the United States could increase by 200 percent.

Do you know a company that embraces social impact? Autonomous Vehicles Silicon Valley is currently accepting nominations for companies that are using MaaS to contribute to the fabric of their local community. If so, nominate them with the Social Impact Awards form and return to