the weather channel, sorry I like a bad pun...
Hi Robert, I am still new at this myself but as I understand it while there is nothing official the folks using them for offroad situations typically use 16 (4X4 equals...) and for the road (travel) people use 19, though there are those that use 20 and you can find out all about the debate by just serching "travel channel" here. I personally just let the radio scan on one level while monitoring the local repeater channel on another.