Is stopping distance dependent upon the number and size of the passengers in a given vehicle?

Question

Is stopping distance dependent upon the number and size of the passengers in a given vehicle?

Answer 1

A heavier vehicle will take longer to stop than a lighter vehicle.  The weight of a vehicle includes the passengers.  Remember, a body in motion tends to stay in motion unless acted on by an outside force.  When you add weight to a vehicle, the size of the brakes and tires do not change.  The more weight in the car, the longer it will take to come to a complete stop.  Look at the warnings regarding the pulling of a trailer.  All manufacturers will warn of increase stopping distances when pulling a trailer.  Why?  Extra weight. Example, into your van you load up 7 large football players each weighing 250 pounds.  This adds a total weight of 1,750 pounds of weight the tires and brakes have to handle during an emergency stop.  

If you think that the extra weight adds extra friction to the tires, then a semi truck with 18 tires on the road weighing 80,000 pounds would stop on a dime and give you change.  Alas, not true.  

Just be aware when you make changes to your vehicle and drive according.

Good Luck

PS wish to add Sheila B's answer is dead wrong.  I have answered your question correctly.  Regarding following distance, the rule of thumb has been either the two second rule or the one car length for each 10 mph.  Both are a little too close for the best safety.  I would offer using a 5 second rule for gaging your following distance.  That will offer your best distance away from the car in front to give you the most time to analyze a situation as it develops and react accordingly.

Answer 2

Stopping distance depends on total vehicle weight, road

conditions, weather conditions, visibility (you won't stop until

you see a reason to), reaction time, speed, condition of

brakes and tires.

Answer 3

No.  It should be measured by car lengths.  You should remain at least three car lengths behind when traveling on any road.