A 2-minute lesson from the Iowa course. Read the rules and examples, follow the handbook page references, and check your understanding before you move on.
Vehicles moving faster or slower than traffic cause more lane changes, passing, and following too closely—and more collisions. The safest roads are where everyone travels the same speed without exceeding the limit.
Know the rule
Always be ready to change your speed to match the speed of traffic.
Many collisions are caused by following too closely. You must be able to stop before hitting anything ahead, and higher speeds need greater stopping distances—use the three-four second rule.
A pickup rides your bumper on a two-lane road. Ease slightly right, signal your upcoming turn early, and slow a bit to encourage it to pass. If it won't, pull off when safe and let it go.
Check your understanding
Read the question, decide on an answer, then open it to check the explanation. These are Roadwise study questions based on the source handbook.
What happens when vehicles travel much faster or slower than the flow of traffic?
Following distances naturally increase
Lane changes, passing, and tailgating increase
Traffic spreads out more evenly
Fewer vehicles need to change lanes
Answer: Lane changes, passing, and tailgating increase
Vehicles moving faster or slower than traffic flow increase lane changes, passing, and tailgating risk.