Awful drivers may stop here (3,4)
I believe the answer is:
the pits
This clue is a double definition.
'awful' is the first definition.
(informal phrase meaning something very bad)
'drivers may stop here' is the second definition.
(Other definitions for the pits that I've seen before include "place in motor-racing?" , "Those places offering a quick tyre change" , "Absolutely worst person possible" , "place to service a car?" , "hell!" .)