I like the Beeline Highway, because there are lot of good traditional caches just off this highway and on our highway cleanup days, we can all contribute items to make a new traditional cache and hide it somewhere just off the Beeline Highway.
 
There is also nothing wrong with having multiple Adopt-a-Highway locations.  We could adopt a highway in southern Arizona for Tucson-area geocachers, and a section in northern Arizona a high elevation which would be a great get-away on those >100° F days of summer in the desert.

Ken Akerman (a.k.a. Highpointer)