Study Suggests That Self-Driving Cars May Consume More Energy Than Cars With Drivers

Will driverless cars consume more energy than cars with drivers? According to a study by researchers at the University of Michigan in Ann Arbor, autonomous vehicles could reverse the trend of declining fuel consumption.

Self-driving vehicles are being developed by many car and technology companies, from General Motors to Google, and they may be showing up on the market soon. Recently, Baidu Inc., the Beijing-based search engine company, stated its plans to have a model on the road this year.

But why would driverless vehicles consume more energy than conventional cars?

The basic answer is that they may make more trips. According to the U.S. National Household Travel Survey, in most households, each adult commutes, runs errands and drives the children around separately. University of Michigan researchers are suggesting a self-driving car would make more trips to finish the same tasks. For example, the autonomous vehicle might drop one parent off at work, then return home to pick up the other parent, then take the kids to school, then return home, and continue this cycle throughout the day.

However, what isn’t known yet is how many people who don’t currently drive, such as children and those who use public transportation, will start sharing a self-driving car. If usage by this segment becomes commonplace, this could result in more total driving time, thereby increasing fuel consumption.

According to calculations by Brandon Schoettle and Michael Sivak of the University of Michigan Transportation Research Institute, increased sharing could mean that Americans would own 43 percent fewer cars (from 2.1 to 1.2 vehicles per household) but would use them 75 percent more (from 11,661 to 20,406 annual miles per vehicle).

“It could be that sharing the vehicle ends up increasing the mileage because of all these connecting trips,” said Schoettle. “The net effect is probably going to be an increase in mileage, and in general the more miles you drive the more fuel you burn.”

However, there’s another important factor to consider when comparing the fuel usage of self-driving and conventional cars. Schoettle explained autonomous cars are able to conserve fuel in other ways. These cars won’t waste energy by flooring the accelerator and slamming on the brakes in the way that many drivers do. Additionally, these cars will be better at avoiding traffic jams and red lights, and will find parking spots without driving around the block over and over. The increased efficiency of the driving abilities of autonomous cars could prove to save significant fuel.

Some other interesting information comes from a 2014 study by researchers at the University of Texas. In the study, it was found that “shared autonomous vehicles” could use 12 percent less fuel and release 5.6 percent less climate-warming gas than average cars. Ride-hailing services such as Uber and Lyft could help to facilitate the increased sharing of self-driving cars over time.

Baidu’s announcement of its plans to have a self-driving car available this year has certainly ramped up the timeline. However, many other companies are either developing or testing the technology, including Mercedes-Benz, Volkswagen, Toyota, Honda, General Motors, Google and Tesla. Some rumors suggest that Apple is also working on a self-driving car.

With so many companies working on autonomous cars, one thing that seems almost certain is that they’re going to be on our roads at some point, and it’s quite possible that it could be soon.

Which company do you think will be the first to offer an autonomous vehicle on the market, and when will it occur?