Yes, you do get an audible warning but you can't customise how far in advance. The cameras are shown on the map but as a small green 'light' which isn't easy to see as you're driving along. I haven't used the option for some time so can't recall how far in advance it warns you but it's almost certainly sufficient time to slow down if you've 'inadvertently' drifted over the speed limit but it probably wouldn't be much good for hard core speeding!