PB, Since you live in Northern VA, as do I, you may notice the same problems I had with my wireless. The local traffic signals use an inductance loop to sense the presence of a vehicle. I found that, as I sat waiting for a light to change, the wireless computer went crazy on me. It would read 67mph, and give me a really treat average speed . This was probably caused by the traffic sensor in the road at the light. It can be so strong a signal that it drowns out AM radio stations!

I gave up on wireless in this area, and I use the old fashioned hard wired versions now.

RB