Sorry if this sounds weird but I keep watching these cop chases on YouTube and keep watching the America chases. One thing I don't understand is why there is the suspect and then a 10 car long line slowly trailing after them. (im from the UK so things might be different here) but I don;'t understand why there is a need for such a long queue of cars driving behind the 1 car who you are chasing. I just don't understand.

EDIT: is it becasue some chases could take a while and some cars could run out of fuel, or you just generally need that amount of backup becasue in America guns are legal

Thanks if you could explin why you do this thanks