The Environmental Benefits Of Autonomous Taxis

As autonomous vehicles edge closer to reality, there is increasing attention given to their potential impact upon society.  Nowhere is focus greater than on the potential environmental impact.  I wrote earlier this year about a study conducted by the University of Michigan into the matter, which suggested that autonomous vehicles could generate energy savings of around 9% over traditional vehicles.

The study has been followed by a second, this time by researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley, who have explored the environmental implications of a fleet of self-driving electric vehicles in Manhattan.

Green cabs

The researchers built models based upon over 10 million taxi journeys undertaken in New York City to predict what impact so called shared automated electric vehicles (SAEVs) might have on greenhouse gas emissions and energy consumption.

“The EV industry is focusing on the personal car market, trying to make the range as large as possible,” the authors say. “The standard now is 200 miles. We suspected you wouldn’t need as much for taxis. We found plenty of times during the day when a portion of taxis could slip off to recharge, even if just for a few minutes. This greatly reduces the need to have a big battery and therefore drives down cost. It is dependent on having a fairly dense charging network.”

The team created an agent-based model that allowed them to simulate the movement of some 7,000 taxis around New York during a day.  On top of this, they developed models to gauge the cost of service and the best place for vehicle charging points.  This modelling discovered that the lowest costs were incurred with a battery range of between 50 and 90 miles, with 44 fast level 2 chargers per square mile, which is roughly three times the current supply in the area.

The study also analyzed the impact on greenhouse gas emissions, and estimated that it could reduce grid requirements in New York City by 73%, or 58% for gas-powered autonomous vehicles.

Electric for the win

The authors believe that electric vehicles are ideal for urban environments where short trips are the norm.  What’s more, they believe that a shared fleet would be perfect and overcome the various barriers to adoption, such as the high cost and limited range of the technology.  If this approach is taken, they believe that it could prove to be the nest big thing in transportation.

“For a long time, personal transportation seemed like the hardest problem to solve,” they explain. “Now suddenly it seems like there’s an obvious path to achieving it, which is the electrification of vehicles coupled with changing the way we get around from private vehicle ownership to shared approaches. Shared approaches are starting to work in urban areas.”

They’re confident that once the technology proves itself, then people will rapidly switch across.  Having previously studied the lighting industry, they were taken by the speed of adoption of LED bulbs after they had proved their value over traditional incandescent bulbs.

“It was a better product and it was cheaper overall,” they say. “When you have those together, people adopt it really fast. I suspect there will be a similar transformation that will occur in the transportation sector in the next decade – it will occur faster than people think.”

Time will tell whether a similarly swift adoption occurs with autonomous electric vehicles.