speed limit noun definition in Controlling traffic topic from the Oxford Advanced Learner's Dictionary

speed limit

 noun: Controlling traffic topic
the highest speed at which you can legally drive on a particular road You should always keep to the speed limit. to break/exceed the speed limit The road has a 30 mph speed limit. He was driving over the 60 mph speed limit. You have to come down that hill in a low gear to keep within the speed limit.