Traffic flow vs. traffic backup

Question

I am frequently puzzled by how one measures/talks about traffic flow. For example, the other day I was driving on a four-lane street (two in each direction) and I came up to a lane restriction near a traffic light. There were about 30 cars in the backup. I thought, it’ll only take two minutes to get through it. But it took ten. When I was halfway through the backup, I thought, that this backup would get much longer, stretching for miles behind me. But it didn’t. I looked behind me and there were about fifteen cars.

I am thinking there are different units needed to describe something moving (flowing traffic) and something stopped (30 cars in one place). So what are they?

In: 3

Answer 1

How many cars are switching lanes and how much slower are people accelerating vs slowing down. You slam on the brakes when entering traffic, and you accelerate away like gas is 100 dollars a gallon, you are the traffic