The principal purpose of
guide signs is to direct travelers to their destinations by the best
route. However, it is not feasible to install signs listing all of the
possible destinations that may be reached from the highway.
Drivers must be expected to make reasonable preparation for locating
their destination and to have information that is readily available on
Determining Guide Sign Messages
Simplicity and clarity are necessary because drivers of moving vehicles
are unable to read lengthy or complicated messages on signs. For this
reason, the number of lines on a sign is kept to a minimum, and should
not exceed 3. On freeways, high traffic speeds demand that the number of
signs be limited to absolutely essential for the guidance of the
motorist. Freeway exits are identified by exit number, the route number
or by the name of the intersecting road. Certain additional messages may
be provided where justified.
In rural areas signs may be installed to direct travelers to services such as roadside rests, gas, food, and lodging.