radar trap
From Longman Dictionary of Contemporary EnglishRelated topics: Motor vehicles, Policeradar trapˈradar trap noun [countable] TTCSCPa place on a road where police wait with radar equipment in order to catch drivers who are going too fast SYN speed trapExamples from the Corpusradar trap• I was pinched for dangerous driving last month, in a radar trap.• And the beam can't be spotted by drivers who use radar trap detectors.