|
The road in front of my house is instructive when it rains. Then, the spray pattern caused by vehicles is easily apparent, due to contrast with the dark farmland in the background.
The visible wake behind vehicles is 4-5 times vehicle height, as the vehicle pulls (drags) the air with it, so any following vehicle encounters airflow already moving in the direction of travel. The closer to the rear of the leading vehicle, the more the dragged air matches the leading vehicle's speed. So, at 50 mph and following several car lengths behind another car, the following car may experience turbulent air with an effective airspeed of, say, 25 mph.
|