mmmm you know that really really busy road that leads out of Edinburgh to the Forth Road Bridge? I think we ought to do some environmental monitoring there.

OK, shall we set it up so that we can access it from a lorry parked on the fairly quiet slip road off?

No, tee hee, let's set it up so we have to block off one of the lanes on the really really busy main road every time we need to do some maintenance.