In a traffic jam, why does traffic completely stop?

Question

I can understand it slowing waaay down, but why should anyone come to a full stop?

Answer 1

It's like flushing too much toilet paper down the toilet. If too many cars on the road, it starts to slow or even stop traffic.

Answer 2

cuz it's jammed!

Answer 3

It's usually blocked lane(s) up ahead and the resulting back-up brings traffic flow to a halt.

Another thing to consider is the ripple effect.  Even though the original cause/problem may have been cleared, the resulting braking action of the cars sends a ripple wave back and can bring traffic to a slowdown or even a standstill long after the fact during heavy traffic times.

Answer 4

Chances are in a jam, there's an accident or a broken down car. It crushes the area of mobility, and some people have to wait for the other cars to pass.

Answer 5

too many cars in one place, not enough road.