Stop Sign Guidelines
Because the stop sign causes a substantial inconvenience to motorists, it should be used only where warranted. A stop sign may be warranted at an intersection where 1 or more of the following conditions exist:
Intersection of a less important road with a main road where application of the normal right-of-way rule is unduly hazardous
Street entering a through highway or street
Unsignalized intersection in a signalized area
Other intersections where a combination of high speed, restricted view and serious accidents indicate a need for control by the stop sign
When to use and not use stop signs:
Stop signs should never be used on the through roadways of expressways.
Stop signs shall not be erected at intersections where traffic control signals are operating.
Where 2 main highways intersect, the stop sign of signs should normally be posted on the minor street to stop the lesser flow of traffic.
Stop signs may be used at selected railroad-highway grade crossings only after their need has been determined by a detailed traffic engineering study.
Portable or part-time stop signs shall not be used except for emergency purposes.
Stop signs should not be used for speed control.
Traffic Signal Guidelines
Traffic control signals should not be installed unless 1 or more of the signal warrants in the U.S. DOT Manual on Uniform Traffic Control Devices (MUTCD) are met. The satisfaction of a warrant or warrants is not in itself justification for a signal.