The system acquires targets (vehicles) in front of your vehicle and shows the range to it and if you are closing on it. If you are going fast and getting close it will change color and beep to alert you in time to a dangerous closure rate so you can stop or swerve to avoid the tart vehicle.
I used on a 5 hour trip from New Jersey to Virginia and it worked great!
I purchased a 2nd 2015 Mercedes GLK to use at my Florida home without realizing it was not equipped with the lane change and collision avoidance systems installed in my original vehicle. After investigating the situation I found the "Safe Drive" system which is very similar to the original factory installed.
The Safe Drive system does not apply the brakes or vibrate the steering wheel if the directional signal is not used as does the factory installed system, but rather provides an audible warning. I had the Safe Drive system installed and am very pleased with the performance. I would not hesitate to have Safe Drive installed in another vehicle should the need arise.