When is it illegal to drive below the speed limit?
- When driving slowly disrupts the normal flow of traffic ✓
- When in heavy traffic in a construction zone
- Only when driving in rural areas.
- When driving under adverse weather conditions
Answer: A. When driving slowly disrupts the normal flow of traffic
Driving below the speed limit is illegal when your slow speed disrupts the normal flow of traffic.
Why this is the answer
The handbook says speed limits exist so traffic can move in an orderly way, and drivers must obey posted minimum limits as well as maximum ones. A vehicle creeping along under the limit when traffic is otherwise moving normally works against that orderly flow, which is the situation the rule targets. The handbook also ties lane choice to speed, telling slower drivers to keep right so faster traffic can get past. It does not say slow driving is wrong in bad weather or heavy traffic; there you are told to adjust your speed.
Why the other answers are wrong
- B. When in heavy traffic in a construction zone — Heavy traffic in a construction zone is a condition where the handbook tells you to adjust your speed, not a situation that makes slower driving illegal.
- C. Only when driving in rural areas. — Nothing in the handbook limits this rule to rural roads; the orderly-flow requirement applies to traffic generally.
- D. When driving under adverse weather conditions — In adverse weather the handbook requires you to slow down and increase following distance, so driving below the limit there is what you are supposed to do.
Remember it
Speed limits are about keeping traffic moving as a group, so if your slow pace is holding up everyone behind you, that is the problem.