It depends on if it was a system that just put radar guns out and issued a ticket to any car that was speeding through its beam (I've never heard of this type)

It depends on if it was a system that just put radar guns out and issued a ticket to any car that was speeding through its beam (I've never heard of this type) or a system that tracked your average speed between two points (I have heard of these). And automated systems do have discretion... it would depend on what +/- tolerance said system was given. I've heard anecdotal claims that a cop won't give you a speeding ticket unless you are exceeding the limit by some X amount.