Insights into Adaptive Cruise Control and Energy Efficiency in Electric Vehicles

This observational study explores the effect of adaptive cruise control (ACC) on energy consumption in electric vehicles (EVs) and contrasts the findings with prior research on internal combustion engine (ICE) vehicles. Using a large real-world driving dataset collected in 2024, we employ statistical methods and show that ACC engagement results in a penalty of +6.81 watt-hours per kilometer (Wh/km) in energy consumption, a 2.5\% increase over the fleet-level average of 275 Wh/km. This penalty is smaller in absolute terms than the +24.20 Wh/km penalty observed in ICE vehicles, primarily due to the superior efficiency of EV powertrains and the mitigating role of regenerative braking. However, in percentage terms, the penalty for EVs is larger than for ICE vehicles (+2.0\%) compared to their fleet baselines, which suggests that ACC systems are less optimized for EVs and disrupt their efficiency more than they do for ICE vehicles. We also show that regenerative braking efficiency varies significantly between ACC ON and OFF modes, with human drivers (ACC OFF) achieving higher efficiency in scenarios with low starting speeds and large decelerations. However, when braking conditions match, ACC marginally outperforms human drivers across most regions of the speed-deceleration map. This research provides critical insights into the interplay between energy-efficient technologies and driver-assistance systems, and highlights the need to optimize automation algorithms to leverage the unique characteristics of EV powertrains, maximize energy recovery, and support next-generation energy management solutions in transportation.