Minimum speed signs are designed to:
- Keep traffic flowing smoothly ✓
- Show current local road conditions
- Test future traffic signal needs
- Assure pedestrian safety
Answer: A. Keep traffic flowing smoothly
Minimum speed signs are there to keep traffic flowing smoothly, so vehicles do not hold up the road behind them.
Why this is the answer
The manual explains that some highways post minimum speed limits to keep a smooth traffic flow. It also warns that a driver going below the minimum can halt the flow of traffic and create a dangerous condition. That is the purpose the signs serve: setting a floor so the whole stream keeps moving together. Nothing in the handbook ties these signs to reporting road conditions, planning signals, or pedestrian protection.
Why the other answers are wrong
- B. Show current local road conditions — Minimum speed signs set a required floor for traffic flow; the manual treats current conditions as something that can make a lower speed unsafe, not as information the sign displays.
- C. Test future traffic signal needs — The passages describe minimum speeds in connection with traffic flow and dangerous slow driving, not with studying whether future signals are needed.
- D. Assure pedestrian safety — Pedestrians are mentioned in the roundabout section about yielding, not in connection with minimum speed signs, so pedestrian safety is not the purpose given.
Remember it
Think of a minimum speed sign as a floor, not a ceiling: it exists so nobody becomes the slow-moving plug in the pipe.
Official handbook: New York State Driver's Manual (MV-21), Chapter 8: Defensive Driving – Speed