Understand the Meaning of the Two Different Speed Signs
For your driver’s license or permit exam, you must know the difference between these two speed signs. One is a regulatory speed limit sign. The other is an advisory (recommended) speed sign.
Remember the Basic Colors
Black and white are used for regulation, yellow is used for warnings.
Regulatory speed limit signs are rectangular and have black letters and numerals on a white background. Speed limit signs tell you the legal allowable limits. You may drive at this speed when conditions allow, but basically you must not exceed the limit under any circumstances. (In Montana, you may exceed the speed limit with 10 mph when passing another vehicle on a two-way road.)
Advisory speed signs have black letters on a yellow background. Advisory speed signs are often seen under a warning sign and typically placed at sharp curves, exits, or exit ramps.
The Advisory Speed Sign
Advisory speed signs tell you that conditions ahead may make it unsafe to drive at a faster speed. You should slow down to the recommended speed. In bad weather or heavy traffic, you should reduce speed even more.
An advisory speed sign is not enforced in the same way as a regulatory speed limit sign.
You should, however, be aware that if you exceed the recommended speed and have an accident, it may be argued that you violated the basic speed law or general speed restriction and were driving too fast for conditions.
In such a situation, you could still be subject to arrest and a later conviction.