An analysis of accidents in great britain has shown that it is important that direction signals on motor vehicles should be readily seen from the front and side as well as from the rear, particularly by cyclists and motorcyclists. In light of this information, the relative merits of present-day examples of semaphore-arm and flashing turn signals for use on cars have been compared. It is concluded, over the wide variety of conditions tested, that a side- mounted amber flashing indicator (the 'amber ear') is the most effective indicator. A rear indicator was found to become less effective the nearer it was to the stop light. There seem to be advantages in mounting signals at drivers' eye-level, and amber colored signals appear better than red or white ones. The side-mounted indicator is likely to be of help to cyclists and motorcyclists, who are the chief victims of serious and fatal turning-car accidents at road intersections in great britain. The importance of standardization in the choice of direction signals is stressed and recommendations are made regarding the choice. /author/
Abstract