When driving at speeds under 30 mph, keep a minimum following distance of:
- One second.
- Two seconds. ✓
- Three seconds.
- Four seconds.
Answer: B. Two seconds.
At speeds under 30 mph, keep a minimum following distance of two seconds behind the vehicle ahead.
Why this is the answer
The handbook gives a two-second minimum following interval when you are traveling 30 mph or less in good road conditions. It explains the counting method: pick a fixed object near the road, start counting when the car ahead passes it, and see how long it takes you to reach the same spot. The handbook also notes that a four-second interval is the better target for a new or less experienced driver, and that poor road conditions call for more time.
Why the other answers are wrong
- A. One second. — One second is shorter than the minimum the handbook sets for speeds of 30 mph or less, so it leaves too little room behind the car ahead.
- C. Three seconds. — Three seconds is not the figure the handbook attaches to speeds under 30 mph; it uses two seconds there and four seconds for speeds above 30 mph.
- D. Four seconds. — Four seconds is the interval the handbook gives for speeds above 30 mph, not for speeds under 30 mph.
Remember it
Think of it as a split at 30: below 30 mph count to two, above 30 mph count to four.
Official handbook: Texas Driver Handbook (DL-7), Chapter 14: Additional Safety Tips , p. 72