A display technology that superimposes images onto the inside of the windshield to enable drivers to view the information while keeping their eyes on the road. Heads-up displays (HUDs) are also used in goggles and helmets (see head mounted display).

Initially used in military aircraft to display avionics and instrument readings as well as gunsights in front of the pilot, heads-up displays migrated to commercial aircraft and later to automobiles. Passenger car systems display vehicle speed and objects detected in a collision avoidance system, such as a deer crossing the road up ahead. See automotive systems.