System for evaluating the driving environment of a motor vehicle and for influencing the speed of the motor vehicle in its own lane, with an electronic control unit, which is connected to a signal generator generating a signal which is characteristic of the desired speed of the motor vehicle, a signal generator generating a signal which is characteristic of the yaw rate of the motor vehicle about its vertical axis, a signal generator which generates, for objects located in the space lying in front of the motor vehicle in its direction of travel, a signal which is characteristic of the distance and orientation of the objects with respect to the motor vehicle and which reproduces the speed relative to the speed of the driver's motor vehicle, and/or the distance relative to the driver's motor vehicle, and/or the angular offset or the lateral deviation relative to the vehicle longitudinal axis of the driver's motor vehicle, and a signal generator generating a signal which is characteristic of the speed at least of one wheel of the motor vehicle, and which unit is connected to at least one control device influencing the road behavior of the motor vehicle in order to supply this with output signals which are derived from the road behavior of the motor vehicle located in front of the driver's motor vehicle, with characteristic values having fluid boundaries being established in the electronic control unit for at least two different road environments (town traffic, country road, motorway) in order to distinguish the type of road on which the driver's motor vehicle is traveling, wherein a quantity influencing the respective characteristic value is the "environmental speed" established from the speeds of the objects detected in the space in front of the driver's motor vehicle and preferably determined by averaging.