Minimum Speed 40 Sign
You may not drive slower than the posted minimum speed
What to do
Maintain at least the posted minimum speed when conditions allow.
Tips
Driving too slowly can be as dangerous as speeding.
Test yourself
You see this sign while driving. What do you have to do?
Show the answer
Maintain at least the posted minimum speed when conditions allow.
Common mistake
Driving below the minimum and impeding traffic
About regulatory signs
Regulatory signs are usually white rectangles with black or red markings, and they carry the force of law — speed limits, turn restrictions, right-of-way. Ignoring one is a traffic violation. The written test regularly checks whether you know exactly what a regulatory sign requires you to do.
Practice the rule this sign carries
A construction zone speed limit sign showing '45' means:
- A. The maximum legal speed through the zone is 45 mph
- B. You should try to drive 45 mph
- C. You may drive faster if conditions allow
- D. The minimum speed is 45 mph
Show answer
A. The maximum legal speed through the zone is 45 mph — Posted speed limits in construction zones are the maximum legal speed for that zone. Driving faster than the posted limit, even if conditions seem to allow it, is illegal and dangerous.
Source: California Driver's Handbook — General Driving · verified 2026-05-17
What is the maximum speed limit on most freeways unless a higher limit is posted?
- A. 70 mph
- B. 65 mph
- C. 55 mph
- D. 60 mph
Show answer
B. 65 mph — The maximum speed limit on most California freeways and divided highways is 65 mph unless a higher limit of 70 mph is posted. On two-lane undivided highways, the limit is 55 mph unless posted otherwise.
Source: California Driver's Handbook — General Driving · verified 2026-05-17
Frequently asked questions
What does the Minimum Speed 40 Sign mean?
You may not drive slower than the posted minimum speed
What should you do at a Minimum Speed 40 Sign?
Maintain at least the posted minimum speed when conditions allow.
Reference standard: Federal Highway Administration Manual on Uniform Traffic Control Devices ↗. State and local agencies may add rules or operating times, so follow the complete posted sign where you drive. How DMV Prep sources content.
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