A speed controller for motor vehicles having an input device for the input of a desired speed V.sub.set by the driver, and having a plurality of operating modes which are able to be activated in different speed ranges and differ in their functional scope. A change in the operating mode, which results in the loss of a safety-relevant function, is provided or enabled by a command of the driver, characterized by a decision unit, which, in the light of predefined criteria, determines whether a change in the desired speed V.sub.set, which is input by the driver, is to be interpreted as a command for changing the operating mode.