Biofidelic human body models (HBMs) with active muscles are valuable tools for assessing the safety potential of systems that are active immediately before and during a crash. For validation, experimental data including muscle activity are required. This paper provides a data set for front seat passengers in autonomous braking events comprising 20 volunteers (11 male and 9 female) in a passenger car. Volunteers were subjected to two different autonomous braking test cases of 1.1 g, wearing a standard belt and a reversible pre‐tensioned belt activated 200 ms before deceleration onset. The following data were collected:​ muscle activity with electromyography, kinematics with video tracking, footwell force, belt force and belt payout. Head and T1 displacements were shorter with a pre‐tensioned belt while head rotation was similar for both test cases. Kinematics did not display any significant gender differences. Average muscle activity with a pretensioned belt increased rapidly before onset of deceleration for females, but not for males. Muscle activity, predominantly in the cervical and lumbar extensors, increased soon after vehicle deceleration onset for all volunteers wearing the standard belt. All muscles were significantly more active during braking than normal driving. Data are presented in corridors for use when validating active HBMs.