Speed limits help law enforcement to curb unreasonable driver behavior by identifying excessive speeds. They also help drivers to know the expectations they must live up to even when driving in an area that is unfamiliar to them.
According to the Minnesota Department of Transportation, there are several different types of speed limits throughout the state. These are consistent to encourage voluntary compliance from drivers.
1. Advisory speed limits
Certain driving situations require drivers to decrease speed for safety. Hazards such as winding roads or curves have advisory speed limits posted to encourage drivers to slow down when navigating them. These are recognizable by black and yellow speed limit notices paired with warning signs.
2. Regulatory speed limits
A regulatory speed limit is the fastest that motorists can safely travel along a given stretch of road when conditions are ideal. The Commissioner of Transportation can authorize a regulatory speed limit based on a traffic study that takes factors such as speed samples, crash history and road condition into consideration. Rectangular signs with black writing on a white background identify regulatory speed limits.
3. Statutory speed limits
The legislative body of each state sets generic speed limits for different types of roadways that apply unless there is another limit posted. In Minnesota, speed limits under Statute 169.14 range between 70 miles per hour on rural interstate highways and 10 miles per hour in alleys. Regulatory speed limits are sometimes equal to statutory limits. However, if there is no speed limit posted, statutory limits apply.
If there is a speed limit posted, it takes precedence over statutory limits. Regulatory speed limits may be either statutory or based on traffic studies.