Autonomous electric taxis could become major contributors to the reduction of pollution in urban areas by 2030, a study has concluded.
According to the study carried out by researchers from the Lawrence Berkeley National Laboratory in California, USA, fleets of driverless electric taxis could produce 90 per cent fewer emissions per mile than privately operated petrol-powered cars. The robocabs could even outperform current hybrid vehicles, which typically generate 82 per cent fewer greenhouse gases.
"When we first started looking at autonomous vehicles, we found that, of all the variables we could consider, the use of autonomous vehicles as part of a shared transit system seemed to be the biggest lever that pointed to lower energy use per mile," said lead researcher Jeff Greenblatt.
Almost half the savings were attributable to what the researchers call the ‘right sizing’ - tailoring the size of a taxi to its occupancy needs, so that a single passenger travels in a smaller vehicle than a party of four.
The researchers also looked into economic factors, considering 2030 as a feasible date for the deployment of the robocabs.
At 12,000 miles per year, electric vehicles were still expected to be more expensive than owning and operating petrol-driven cars. However, at 40,000 to 70,000 miles a year, power delivered by a hydrogen fuel cell or electric battery was the most cost-effective option. Such distances are not uncommon for a taxi to travel in one year.
The assessment, published in the latest issue of the journal Nature Climate Change concluded that although installing autonomous technology in a car would cost an additional $150,000 (£96,200) on top of the cost of a vehicle, removing the human operator would further improve energy efficiency.
The reason for this is that self-driving cars can drive closely behind each other, providing wind resistance. They also follow the most efficient routes and accelerate and brake more smoothly.
"These are all incremental, but they do add up," Greenblatt added. "However, we didn't even include these effects in our baseline results and we still get huge savings without them."
The authors of the paper believe that by 2030 autonomous taxis could be far cheaper to operate than their human-operated counterparts.