Self-Driving Trucks and Beacon Navigation

If self-driving trucks are indeed going to be a mainstay of our shipping in the future, as is widely predicted, there have to be some rough edges in replacing human drivers.  A human driver can do things like take shortcuts, memorize a route taken many times before, and ask for directions if lost (human pride nonwithstanding.)

So how would a self-driving vehicle have the same adaptability?  It can 'see' where the road is and use built-in, offline navigation to navigate alternate routes, and if it has connectivity, phone home and ask for help or directions.  

But what if it doesn't have connection, is taking a road it doesn't really know or is on any map, and gets lost?  There are certainly many places like this even in the US, and certainly in other localities less documented.

What if, in these cases, major routes used for shipping that are outside of a good connection had small bluetooth beacons next to the road that communicated basic location/map information?  The vehicle could use it to find its way to the next beacon, kind of like crumbs through a forest.  These beacons could be powered by small solar panels, which would be more than enough for the small amount of juice needed to keep them running.

It could be a relatively expensive solution in the short term, as each beacon can run $10-20 per, and the range is maybe 10-20 meters at best.  But if they become significantly cheaper or have much wider range, you could run them along major delivery routes not really on any map (and be used by navigational devices).

To illustrate how this could work, I give you... a double rainbow: