Speeding behavior while using adaptive cruise control and lane centering in free flow traffic.

Area of Science:

• Automotive Engineering
• Human Factors in Transportation
• Road Safety Research

Background:

• Adaptive Cruise Control (ACC) and lane centering are advanced driver-assistance systems (ADAS) often perceived as convenience features.
• While ADAS offer potential safety benefits, their impact on driver behavior, particularly speeding, requires thorough investigation.
• Speeding is a significant factor contributing to increased crash risk and severity.

Purpose of the Study:

• To characterize speeding behaviors of drivers utilizing ACC.
• To compare speeding patterns between ACC, ACC with lane centering, and manual driving conditions.
• To identify factors influencing speeding when using ADAS.

Main Methods:

• Recruited 40 licensed adult drivers from the Boston metropolitan area.
• Provided participants with either a 2017 Volvo S90 or a 2016 Range Rover Evoque for approximately four weeks of use.
• Monitored driving behavior and speed relative to posted limits during system engagement and manual control.

Main Results:

• A high percentage of drivers (95% for ACC, 96% for ACC with lane centering) exceeded speed limits compared to manual control (77%).
• Drivers using ADAS also tended to exceed speed limits by a greater margin than when driving manually.
• Speeding differences were most significant on limited-access roads with 55 mph speed limits.

Conclusions:

• Frequent and elevated speeding while using ACC and lane centering may impede the full realization of their safety potential.
• The net safety effect of these ADAS must consider the behavioral tendency of drivers to speed.
• Future safety assessments of ADAS should incorporate the impact of driver speeding behavior.