Naturalistic Driving Behavior Analysis under Typical Normal Cut-in Scenarios 2019-01-0124
Cut-in scenarios are common and of potential risk in China. Brake is considered as an express of risk. In order to improve the acceptance of ADAS, brake tendency in normal driving needs more investigation. Under critical Cut-in scenarios, driver tends to brake to eliminate collision risk when cutting in vehicle right crossing lane. Cutting in vehicle is called target vehicle, TV for short. However, under less critical Cut-in scenarios, driver brakes in some cases and takes no brake maneuver in others. The time when driver initiated to brake was defined as key time. If driver had no brake maneuver, the time when TV right crossed lane was defined as key time. Environment factors (for example, traffic condition and road type), TV type and motion factors greatly influence driver’s reaction to TV at key time. To comprehensively take those factors into account, cluster analysis was adopted to extract typical Cut-in scenarios from naturalistic driving database. Seven typical scenarios as well as driver’s behavior data were obtained. It was found that under the scenarios featured by smooth traffic and open road, THW (Time headway) at key time is larger and has a wider range; and when driving environment is smooth traffic and enclosed road, means of relative velocity at key time is largest and distribution range is wider than others. There exist certain linear relationships between THW and relative velocity. The linear correlation is stronger when driver brakes and also influenced by driving environment. In each typical Cut-in scenario, driver's brake behavior was demonstrated by scatter plot on THW-relative velocity plane. This plane was divided into several zones where driver tends to brake or not to brake. A special situation is that TV surpasses subject vehicle and merges in a brutal way and under such situation driver more likely brakes.