Cruise Control and drive by wire.

[medicineman]

My associate asked me a interesting question regarding where and when it was appropriate to use CC. I passed the question onto my IAM branch to be told that using CC to control speed in an urban area was not favoured by the IAM in case it went wrong. I decided to reflect on this and came to the conclusion that we rely on other electronic in a car eg speedo. On top of this many modern cars have a drive by wire throttle and some Mercs have wired brakes. What do you people think of this? Is it ok to use CC as a speed limited or should we be aware enough of our speed not to need CC?