Brake responses of unsuspecting drivers to signals by a conventional brake-lamp system with and without supplemental high-mounted brake lamp(s) were compared. The experiment was conducted under normal daytime traffic conditions at speeds of 48-72 kph. The signals given by the systems with one or two supplemental high-mounted brake lamps were found to be more likely to produce a brake response by a following driver. On the other hand, the reaction times of the brake responses did not vary between the systems. The implications of the findings as well as comparisons with other relevant studies are discussed. The study of Malone et al. (1978) is cited, in which a reduction was found in rear-end collisions of taxicabs equipped with a single supplemental high-mounted brake lamp. Aspects for future evaluation are suggested: other reactions (e.g. taking foot off accelerator but not braking, changing lanes); the novelty effect; and the absence of deceleration during signal presentation. For the covering abstract of the conference see IRRD 268805.
Abstract