Seat belts, child seats and safe following distance

Key points

1. Every person in a passenger vehicle must wear a safety belt.

   Source: Handbook p. 35

   “Massachusetts law requires every person in a passenger motor vehicle (including vans and small trucks under 18,000 lbs.) to wear a safety belt”
   Massachusetts Driver's Manual, Handbook p. 35

2. A driver can be fined $25 for each unbelted passenger aged 12 to 15.

   Source: Handbook p. 35

   “A driver can also be fined $25 for each passenger age 12, 13, 14, or 15 who is not wearing a safety belt.”
   Massachusetts Driver's Manual, Handbook p. 35

3. You can only be fined under the seat belt law when stopped for another traffic violation.

   Source: Handbook p. 35

   “You can only get a fine for the safety belt law when you are stopped for a traffic violation.”
   Massachusetts Driver's Manual, Handbook p. 35

4. Children must ride in an approved child restraint until they are at least 8 years old or 57 inches tall.

   Source: Handbook p. 36

   “Infants and small children must sit in federally approved child passenger restraints until they... 1. Are at least eight years old or 2. At least fifty-seven inches tall”
   Massachusetts Driver's Manual, Handbook p. 36

5. Never put a rear facing child seat in front of a passenger air bag.

   Source: Handbook p. 36

   “Never put a back-facing child safety seat in the front passenger seat if your vehicle has an air bag for that seat.”
   Massachusetts Driver's Manual, Handbook p. 36

6. Most crashes happen within 25 miles of home, and 8 of 10 at 40 mph or less.

   Source: Handbook p. 38

   “Most motor vehicle crashes happen less than 25 miles from home. Eight out of ten crashes happen at speeds of 40 mph or less.”
   Massachusetts Driver's Manual, Handbook p. 38

7. Use the three second rule; it is the minimum for good conditions and moderate traffic.

   Source: Handbook p. 43

   “The three-second rule is a minimum safe distance for good road conditions and moderate traffic.”
   Massachusetts Driver's Manual, Handbook p. 43

8. Keep at least 4 seconds behind a motorcycle and at least 10 seconds behind heavy equipment.

   Source: Handbook p. 43

   “Keep more space (at least four seconds) behind a motorcycle than you would for another vehicle. • Keep more space (at least ten seconds) between your vehicle and heavy equipment”
   Massachusetts Driver's Manual, Handbook p. 43

9. Tailgating is illegal and the main cause of rear end crashes; the fine can be as high as $100.

   Source: Handbook p. 43

   “Tailgating is illegal and the main cause of rear-end crashes. The fine for tailgating can be as high as $100.”
   Massachusetts Driver's Manual, Handbook p. 43

10. If someone tailgates you, move to another lane or pull over to let them pass.

    Source: Handbook p. 43

    “If a tailgater is behind you, move to another lane or pull to the side of the road to let the tailgater pass.”
    Massachusetts Driver's Manual, Handbook p. 43

Numbers to know

3 questions from the Massachusetts practice test

1. 1. Under Massachusetts law, how much can a driver who is not wearing a safety belt be fined, and when can that fine be issued?

   1. $100, at any time
   2. $500, and only after a crash
   3. There is no fine for adults
   4. $25, and only when the vehicle is stopped for a traffic violation
   Show answer

   $25, and only when the vehicle is stopped for a traffic violation. Massachusetts enforces the safety belt law as a secondary offense: the $25 fine is issued only when the vehicle has been stopped for some other traffic violation. The fine is not $100 or $500 and it does not depend on a crash. The manual's larger point is that belts cut the chance of death or serious injury in a crash by about half, so the fine is the least of the reasons to buckle up. The driver can also be fined for each unbelted passenger age 12 to 15.

2. 2. What rule does the Massachusetts manual give for keeping a safe distance behind the vehicle in front of you?

   1. The one-second rule
   2. The one car length per 10 mph rule
   3. The three-second rule
   4. The fifty foot rule
   Show answer

   The three-second rule. Massachusetts measures following distance in time. Pick a fixed object, wait for the vehicle ahead to pass it, and count; if you reach it in less than three seconds you are too close. The manual calls three seconds a minimum for good conditions and moderate traffic, and asks for at least four seconds behind a motorcycle and more in rain or at night. Car lengths and fixed footages are older rules that fail to scale with speed, and one second leaves no reaction time at all.

3. 3. What following distance does the Massachusetts manual call a minimum for good road conditions and moderate traffic?

   1. One second
   2. Ten seconds
   3. One car length
   4. Three seconds
   Show answer

   Three seconds. The three second rule is the floor, not the ideal. In good weather and moderate traffic, three seconds behind the vehicle ahead gives you time to notice a problem and stop. One second is not enough for reaction time alone, ten seconds is more than traffic allows, and car lengths do not scale with speed. Add time at night, in rain, behind motorcycles and large trucks, and whenever the road ahead is hidden.

Source: the Massachusetts Driver's Manual, Chapter 2: Safety First. 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.