The analysis updates and expands previous research in which rollover critical events were classified based on a detailed review of approximately 500 police-reported single-vehicle rollover crashes of ESC-equipped vehicles. In order to compare the rollover performance of vehicles with and without ESC for the present study, an additional sample of more than 300 police reports on non-ESC single-vehicle rollovers was obtained, and detailed coding of rollover scenarios was performed. The coding effort was undertaken by an engineering team and focused on critical events leading to rollovers (departure from road, loss of directional control, impact with an object, and departure from road with possible driver’s input);​ driver factors (impairment, speeding, inattention, distraction, fatigue, and overcorrection);​ and environmental factors. A comparison of vehicles with and without ESC was performed to characterize differences in types of critical events leading to rollovers.