Entrance signs warn traffic of driveways that have poor sight distance*. Common uses for entrance signs include TRUCK, PARK, SCHOOL, CHURCH, PLANT, and HOSPITAL. If the driveway traffic is seasonal, the sign must be removed or covered during the off-season.
While these signs may help increase awareness of entering traffic, they do not relieve drivers of their responsibility to enter the roadway safely. Also, as the number of entrance signs increases, their effectiveness decreases. Therefore, these signs should be used sparingly and only when absolutely necessary.
* For this situation, sight distance refers to how far oncoming traffic can be seen by the driver attempting to enter or cross the roadway. When sight distance is poor, the visual obstruction should be removed, if possible. This can often be accomplished by trimming back trees, bushes, etc. Increasing the sight distance will always have a greater positive impact on safety than installing a sign.