Robo-taxis, what are they good for? Er, the environment and traffic

Taxi firms that move from human drivers of gas-powered cabs to automated electric taxis could cut vehicle emissions by over 90 per cent, according to a study by the Lawrence Berkeley National Laboratory.

Most of these emission cuts come from shifting from oil power to electric, but the study found that autonomous taxi services have a couple of advantages that make them more efficient than private electric vehicles. The study, which looks at predictions for car use in 2030, sees two key areas of savings.

Firstly, the style of car dispatched can be fitted to the ride, with smaller vehicles delivering the majority of taxi rides, which consist of one or two people without luggage. More capacious vehicles can be reserved for larger groups with lots of baggage.

Secondly, given the short range of most taxi rides, electric cars are more cost efficient than petrol cars. That is even more important when you add in the effects of having autonomous vehicles, Dr Jeff Greenblatt, coauthor of the paper published in Nature Climate Change, told The Register.

"Taxis are used much more than private cars, so the number of electric miles traveled really changes the economic equation," he explained.

"We found that, based on simple economic model, an electric taxi would be more cost effective today, but for current driven vehicles the range is short for electric. When you take them offline for charging it's inconvenient for the driver, but a robot doesn't care so much about that and would be part of a fleet."

Thus, shifting to electric, autonomous taxis in 2030 would cut vehicle emissions by 90 per cent compared to a gas-powered car on the road today. If 5 per cent of the cars sold in 2030 were electric, that would equate to saving 7 million barrels of oil per year and would reduce annual greenhouse gas emissions by between 2.1 and 2.4 million metric tons of CO2 per year.

There are other factors to consider with automated vehicles, both good and bad, Greenblatt explained. On the plus side, autonomous vehicles can drive closer together on the road to reduce congestion and increase efficiency, by allowing cars to slipstream each other.

The downside of all this technology, however, is that the estimated quarter of a million people who earn their living as licensed taxi drivers, and those who freelance on services like Lyft and Uber, would be out of a job.

"I don’t think there's an easy answer to that – it's another example of technology having a big change on workers," Greenblatt said.

"It's something that we don’t plan for well as a society and it really should be considered. We don't know where the new jobs will open up, we'll just have to let the market work and be compassionate." ®