The Oxfordshire police force here in the UK have introduced speed cameras. The way they work is to use radar to check oncoming cars speeds, and if its over the limit the camera takes a picture of the cars number plate. I guess a human back at police HQ has to do the bit about reading the plate, and then a fixed fine is sent through the post. They admit that there's a lot of dummy speed camera warning signs, as they only have 3 to cover the whole of the county. What they do is move the cameras around every now and then. Most regular motorists know where they are, as they're easy to see - big grey boxes in the middle of the road. Apparently ( I have no figures ) they've been a great success and police are amazed at how much speeding goes on ( I'm not ). Jon.