Very local thick fog there, the police car go from clearly visible to gone in seconds, and the camera truck just carry on like nothing happened.
That being said leaving my friends house last night for the first few miles i bitched about drivers with their fog lights on as it was only very little lowered visibility there, but a bit further down the road i ran into pea soup,,,, and truth be told i drove too fast too.
but it was a gradual change here went from 1 KM visibility to <100 M 10 Km from there.
Still those drivers i bitched about they should turn off their fog lights after they got out of the soup, they are only for use in case of severe loss of visibility ( you can barely see tail lights of car in front of you ) and 1 KM LOS and a light rain are not fog-light weather.