If you have no "worries" around..I would go out and ask first of all if I could help since he is in my driveway..or if there is a problem..and then depending up on the reason for LEO in your driveway..if he is just sitting ..might be doing paperwork after a local call..any # of reasons..ask them if they drink coffee and would like a cup..I have before. Before I remarried I was very paranoid being alone and actually enjoyed seeing them around...We have a gate now so I don't see anyone in our driveway except us anymore...or expected visitors. I am not sure about legal..pull up your local ordinances?