En förberedande intervjuundersökning röorande gult blinkande sken i trafiken. (A pilot interview study concerning yellow flashing lights in road traffic.)

As a pilot a study to an investigation of yellow flashing lights in road traffic 150 interviews were made in connection with existing flasher installations. The results indicate that knowledge about the general meaning "caution" is fairly good, but that knowledge about, and interpretation of, more specific flashing signal situations is considerably worse.