Mercedes-Benz’s appropriately named Active Distance Assist DISTRONIC’ accurately portrays system functionality. The promotional material and the handbook correctly indicate the limitations of the system capabilities. System status information is clearly displayed in the driver’s direct line, in the instrument cluster and via by a head-up display. The C-Class checks that the driver’s hands are kept on the steering wheel, and acts appropriately if they are not, but a direct driver monitoring system is not used. The system balances driver steering input with lane guidance, promoting co-operative driving.

The C-Class combines map-based speed limit information with real time camera inputs to manage fixed, variable and temporary speed limit signs. The system adapts speed for upcoming road features such as curves and junctions. The C-Class responds to avoid a collision in almost all of the ACC test scenarios. The driver is supported through the S-Bend, staying within the lane at all test speeds. The vehicle has an Active Blindspot system designed to prevent lane changing into adjacent vehicles. A lane-change assist function is provided. In case of an unresponsive driver, the C-Class automatically moves to the slowest lane and performs a controlled stop. If the radar or camera is blocked the car provides a timely warning and prevents system activation.

The C-Class from Mercedes-Benz provides very good Vehicle Assistance with a similar level of Driver Engagement. Combined with excellent safety back-up, the system, overall, offers Very Good highway assistance.