Analysis of Disengagements in Autonomous Vehicle Technology

The paper presents an analysis of the data currently available on disengagements of autonomous vehicles. The data was reported by manufacturers that are currently testing on California public roads to the Department of Motor Vehicles. The results focus on examining reported contributory factors and probable causes of the disengagements and on drawing preliminary estimations of disengagement frequencies and average mileage driven before disengagement. Disengagements do not necessarily lead to an accident (with on average 1 accident occurrence every 178 disengagements actually resulting in a collision or other injury to people/property). We highlight the importance of examining disengagements as precursors of transportation accidents, thus providing an added layer of “defense” for safety practitioners and researchers to study contributory factors and prevent future accidents.