Those warning triangles that cars are equipped with seem pretty ineffective to me.
Today’s invention provides a way for motorists in distress to communicate more effectively. When the “! Hazard !” button is pressed on the dashboard, a small projector would display a bright, single-word message on any suitable surface (eg the rear bumper of the vehicle). This would need to be large enough to be seen in time for automotive samaritans to react safely. No need for a super-clever computer-driven laser micro-projector -Something simple like a bright torch, a colour filter (to contrast the message with the car body colour) and a ‘carousel’ of word templates would suffice here.
The word could be chosen from a restricted list, including: ” Help!, Breakdown, Diall999, Doctor?, Toilet, Fuel? ” and could flash on and off, so that the movement would make the message more noticeable.