They say the best way to get away with anything is to be open and act like you know what you're doing. There was an occassion where a pair of POWs excaped from a NAZI POW Camp by having one of them with a tape measuring doors, gates, lamp posts, whatever, while the other jotted down the leasurments in a notebook. They walked out the front gate and across germany into the Alps doing that without being stopped. Another case was the theft of a USAF firetruck from a base in the Philippines. They just turned on the lights and siren and the gate guards stopped traffic for them.
Best urban camouflage known to mankind is a Hi Viz workmans site vest and a hardhat.