Shared autonomous electric vehicles (SAEVs) could reduce emissions, energy use and overall costs, according to researchers who used a mathematical model to predict the results of the use of automated electric taxi fleets in Manhattan.

The team published its findings in the paper ‘Cost, energy and environmental impact of automated electric taxi fleets in Manhattan’ in the journal Environmental Science & Technology. It details the use of an agent-based model to predict the battery lifespan and charging station requirements of a fleet of SAEVs on Manhattan Island.

“We also developed a model to estimate the cost and environmental impact of providing service and performed extensive sensitivity analysis to test the robustness of our predictions,” said the researchers in the report.

Gordon Bauer, Jeffery Greenblatt and Brian Greke varied the types of vehicles and charging infrastructure to determine which combination would be the most cost-effective. They concluded that around 6,500 vehicles with a battery range of 70 miles could be sustained on 1,500 medium-power electric vehicle chargers.

A fleet of SAEVs this size would produce 33,000 tons of carbon dioxide per year, a 73% reduction over the emissions produced by a petrol-powered fleet of a similar size, and a 57% reduction over a hybrid fleet. Energy consumption would also be reduced by up to 55% compared with a fleet of gas or hybrid vehicles.

The team predicted that the cost of service provided by an SAEV fleet would be $0.29-$0.61 per revenue mile, a figure $0.05-$0.08 per mile lower than that of an automated fleet composed of any currently-available hybrid or gasoline-powered vehicle. They concluded that total operating costs would be reduced by 18%.

“Shared automated electric vehicles (SAEVs) hold great promise for improving transportation access in urban centres while drastically reducing transportation-related energy consumption and air pollution,” they said.