Measuring adult drivers' use of Level 1 and 2 driving automation by roadway functional class

November 2019

Little is known about the use of driving automation in production vehicles. This study measured mileage driven on different roadway classes when Level 1 and 2 automation was engaged. Volunteer drivers drove for 4 weeks in a Range Rover Evoque with adaptive cruise control (ACC) or a Volvo S90 with ACC and Pilot Assist (PA) with one of two versions of PA software. The highest percentage of mileage driven when the automation was on/active (39.5%) was on interstates, other freeways, and expressways. The Evoque's ACC was engaged for a higher percentage of miles than the S90's ACC or PA. The S90's software change was associated with a doubling of mileage driven on interstates, other freeways, and expressways when PA was on/active. The study identified potential misuse with some drivers engaging automation for relatively high percentages of mileage on road classes where owner manuals indicate use may be inappropriate.