Designing a warning device that provides a clear, unambiguous message to the motorist can be a difficult task. The difficulty is due in part to the concern of the engineer to act in a “reasonable and prudent” manner. Increasing motorist safety and minimizing liability require that the device provide a readily understood and unambiguous message.
In the design of warning signs, it is important to remember that signs are designed to draw attention to themselves through contrast, color, shape, composition, reflector — ization, and illumination, with a simple message providing a clear and understandable instruction to the motorist. Sign size, symbol size, lettering size, and placement should be such to allow adequate time for proper response. Uniform and reasonable instructions to the motorist will instill respect and develop willing compliance with the sign message. For these reasons, the majority of general warning signs should be designed as diamond shapes with black letters on a yellow background. Standard sign letters are prescribed in FHWA Standard Highway Signs, which should be used to develop lettering size and style [9]. Sections 2C.01, 2C.02, 2C.03, and 2C.04 of MUTCD contain information that must be followed in the design of warning signs. In addition, Sec. 1A.11 of MUTCD lists additional publications and documents that provide requisite information for the proper design of warning signs.
