主题：说说踩错这件事情，以及根本避免之法 -- 哈酷

好多车现在都有。举个例子。BMW：

外链出处

Driving on busy highways and freeways is more relaxing with Active Cruise Control. It maintains the desired speed when possible, while also keeping a pre-defined distance to any vehicles in the lane ahead.

Radar sensors at the front of the vehicle permanently scan the road ahead. As your BMW approaches a slower vehicle, Active Cruise Control automatically reduces power output from the engine and gently applies the brakes, holding your BMW at a pre-defined distance to the vehicle ahead.

This distance is set as a number of seconds, not of metres, so that a safe reaction time is always available, relative to the current speed. When the lane ahead becomes clear, Active Cruise Control automatically increases your vehicle's speed to your preferred cruising speed. Up to four different cruising speeds can be pre-programmed. A touch on the accelerator or brake pedal deactivates the system.

On curves, Active Cruise Control uses data from the DSC and navigation systems to calculate whether the cruise speed needs to be adjusted, and to determine whether vehicles in the radar's field are in the same or a neighbouring lane.

The high-performance radar sensor is heated in cold weather, ensuring year-round operation. Active Cruise Control is functional at speeds above 30 km/h and below 180 km/h. The system is not intended to serve as an autopilot: outside these speeds, and if sudden deceleration is required, the driver is alerted by a warning sound and visual message.