A large projection screen was used in conjunction with a stationary vehicle to investigate the most appropriate way of presenting headway information to drivers. Videos of moving approaches to a parked vehicle were shown on the screen, and overlaid by various auditory and visual displays to simulate head-up presentation of headway information. Subjects seated in the stationary vehicle were required to operate the brake pedal to indicate the last moment at which braking must commence in order to avoid collision with the vehicle shown on video. Objective measures of subjects' braking responses were captured via activation of the brake pedal, and subjective preferences concerning the various interface options were recorded by questionnaire. Analysis of the objective data showed a significant difference between ‘abstract' and ‘pictorial’ display conditions, with the ‘abstract’ condition producing earlier braking. 'Ihe subjective data revealed that subjects preferred the ‘abstract' visual display and a non-speech auditory display. The findings are discussed with respect to the design of collision avoidance headway displays. The work reported here was conducted under the BRIMMI project:​ part of the EUREKA PROMETHEUS Programme.