Following distance, lane changes and headlights

Key points

1. At 55 mph it takes about 300 feet, one city block, to stop on dry pavement.

   Source: Handbook p. 21

   “At 55 miles per hour, it takes approximately 300 feet or one city block on dry pavement to stop.”
   North Dakota Noncommercial Driver License Manual, Handbook p. 21

2. Use the three second rule: if you reach the mark before counting one thousand and three, you are too close.

   Source: Handbook p. 22

   “If you reach the spot before you count “onethousand-and-three,” you are following too closely.”
   North Dakota Noncommercial Driver License Manual, Handbook p. 22

3. Sometimes you need four or more seconds of following distance.

   Source: Handbook p. 22

   “Sometimes you need even more following distance, as much as four or more seconds.”
   North Dakota Noncommercial Driver License Manual, Handbook p. 22

4. Change only one lane at a time, and cancel your signal afterward.

   Source: Handbook p. 21

   “Change only one lane at a time and be sure to cancel your signal when you complete the lane change.”
   North Dakota Noncommercial Driver License Manual, Handbook p. 21

5. The driver changing lanes is responsible for doing it safely.

   Source: Handbook p. 21

   “The driver of the vehicle making the lane change is responsible for safely changing lanes.”
   North Dakota Noncommercial Driver License Manual, Handbook p. 21

6. For a right turn, stay as far right as possible and turn close to the right curb.

   Source: Handbook p. 22

   “When approaching an intersection to make a right turn, stay as far to the right as possible. Make the turn close to the right curb.”
   North Dakota Noncommercial Driver License Manual, Handbook p. 22

7. Use headlights when rain, snow, smoke or fog cuts visibility below 1,000 feet.

   Source: Handbook p. 24

   “Use your headlights during inclement weather when visibility is less than 1,000 feet due to rain, snow, sleet, hail, smoke, or fog.”
   North Dakota Noncommercial Driver License Manual, Handbook p. 24

8. Dim your headlights at least 500 feet before meeting traffic and within 300 feet when following.

   Source: Handbook p. 25

   “Dim your headlights at least 500 feet before meeting traffic and within 300 feet when following another vehicle.”
   North Dakota Noncommercial Driver License Manual, Handbook p. 25

9. Never back up on the interstate; if you miss your interchange, go on to the next one.

   Source: Handbook p. 24

   “Never back up on the Interstate. If you miss your interchange, go on to the next one.”
   North Dakota Noncommercial Driver License Manual, Handbook p. 24

Numbers to know

3 questions from the North Dakota practice test

1. 1. How can the three second rule help you measure following distance?

   1. Use a fixed car-length gap at every speed
   2. Reach the same mark after about two seconds on a dry road
   3. Reach a roadside mark at least three seconds after the vehicle ahead passes it
   4. Count seconds from the moment you begin following
   Show answer

   Reach a roadside mark at least three seconds after the vehicle ahead passes it. The three second rule uses a fixed roadside object as a time check. Begin counting when the rear bumper of the vehicle ahead passes the mark, and make sure your vehicle does not reach that spot before one thousand and three. Arriving sooner means the cushion is too small. One second, a fixed number of car lengths, or a traffic signal timer cannot account for changing speeds and road conditions. Use a shadow, mark, or other object, then increase the interval when conditions call for more room.

2. 2. For how long before a turn must a driver continuously signal?

   1. Only while the steering wheel is being turned
   2. The last 25 feet before the turn
   3. The last 100 feet before the turn
   4. At least 500 feet on every roadway
   Show answer

   The last 100 feet before the turn. The manual requires a continuous turn signal during the last 100 feet before a turn. Starting the signal only as the wheel moves gives other road users too little notice, while 25 feet understates the required distance. The 500 foot choice overstates the rule and would not be the stated general requirement. Signal before the final approach, keep it on through the last 100 feet, check pedestrians and traffic, then make the turn when clear.

3. 3. When changing lanes, which sequence is required by the manual?

   1. Make sure the lane is clear, signal, and change only one lane at a time
   2. Signal after crossing the line, then move across two lanes together
   3. Change lanes in an intersection whenever traffic is light
   4. Rely on mirrors alone because shoulder checks are unnecessary
   Show answer

   Make sure the lane is clear, signal, and change only one lane at a time. A safe lane change begins with confirming that the destination lane is clear and signaling the movement. The manual adds that drivers should check mirrors and look over a shoulder for blind spots, avoid changing within an intersection when possible, and move only one lane at a time. Signaling late, crossing two lanes in one sweep, or trusting mirrors alone removes important checks. After the move, cancel the signal and confirm the vehicle is centered.

Source: the North Dakota Noncommercial Driver License Manual, Rules of the Road. This lesson is a plain English summary, not the law itself; where it differs, the manual and the statute govern. Last checked 2026-09-27.