Which statement about Illinois' speed limits is true?

• A. You must never exceed posted speed limit
• B. You should never drive so slow as to impede the flow of traffic
• C. You are only permitted to drive at the posted speed limit under safe conditions
• D. All of the above

Answer: (D)

Speed limits are the maximum speeds you may legally drive, not a target you must always hit. You must not exceed the posted limit. You also should not drive so slowly that you impede the flow of traffic, since slow driving can create hazards and may be unlawful. You are allowed to drive at speeds below the posted limit when conditions require it—rain, fog, construction, or heavy traffic often make slower speeds safer. When conditions are safe, you may travel at the posted limit, but you must always adjust to keep traffic moving safely. So in Illinois, these statements line up: speed limits are maximums, you should adjust your speed for safety, and you should avoid impeding traffic; together, they describe the correct approach to speed.