In tested the Volvo XC-60 Adaptive Cruise Control:

I was in our Volvo XC60 a couple days ago for an early morning drive and found it to be an effective highway cruiser. The cabin is pretty quiet at speed, the driver seat is comfortable (though not as those in other Volvos) and the turbocharged inline-6 provides plenty of grunt for passes or when going up steep grades.

I also took the opportunity to fiddle around with the adaptive cruise control. Adaptive cruise control works by monitoring the distance of vehicles ahead of you. You just set your speed and the minimum distance gap. When the XC60′s radar sensor detects a slower vehicle within that preset range, the XC60 automatically applies its brakes to adapt to that vehicle’s speed.

Our Volvo is the only long-term car in recent memory to have this feature; it’s part of the $1,700 Technology Package. Overall, the XC60′s adaptive cruise control worked well for the two hours of driving on straight highway that I used it on. It’s not a must-have feature by any means, but it is nice in that it eliminates the traditional need to cancel and reset your cruise speed every time a slower vehicle gets in your way.

The only thing I noticed was that the XC60′s cruise-speed adjustment buttons seem to bump you up or down in 5-mph increments, which is excessive. Presumably, there’s a way to switch this back to the more normal 1-mph increment, but I didn’t have the opportunity to RTFM.