Combined Maximum and Minimum Speed Limits sign

What to do

Keep your speed between the two numbers when conditions allow. The Minimum Speed Limit plaque (R2-4P) carries the same rule under a regular Speed Limit sign.

Keep your speed between the two posted numbers when conditions are good, and if you cannot safely reach the minimum, leave the road or use a different route.

Where it's used

Section 2B.24 allows a minimum speed limit where engineering judgment finds that slow vehicles might impede the normal, reasonable movement of traffic. The minimum can be shown on a Minimum Speed Limit (R2-4P) plaque mounted below a Speed Limit sign, or the single combined R2-4a sign can be used instead. It is a vertical black-on-white rectangle showing SPEED LIMIT with the maximum above MINIMUM and the lower number.

Don't confuse it with

• Speed Limit: The standard Speed Limit sign gives only the maximum; this sign also sets a legal minimum speed.
• Slower Traffic Keep Right: SLOWER TRAFFIC KEEP RIGHT tells slow drivers which lane to use, while this sign sets a speed below which you may not legally drive in good conditions.