I'm in SF Bay area and have noticed a strange issue with navtraffic. I commute everyday across San Mateo bridge and in the middile of the bridge flow info disappears from the navi and reappears 5 to 10 minutes later. I don't see how it can be a reception problem as the bridge is out in the middle of the bay without any buildings or other obstructions blocking satellite view. Plus, XM reception is constant and in other places where XM reception is blocked temporarilly, traffic flow remains on screen. There are large power lines paralleling the Bridge, but as I said, XM reception is not affected.
Can anyone explain this behavior?

 

I am not sure; however, there was mention of the navtraffic issues being location specific. See this thread for more information: https://acurazine.com/forums/showthread.php?t=1192

 

If it is location specific, then it must be a computational issue within the Nav unit because XM reception is not the problem.