I'm taking an after-Christmas road trip from Charlotte to Chicago, and driving on a variety of roads in several different states, where the car switches from FSD Beta (10.8) to NoA, and back, has convinced me that there is no easily-discernable rhyme or reason to it.
- On true interstates (I-nn designations), and limited access highways that for all intents and purposes interstates just without the "I", it always uses NoA
- On "downtown" style city streets, it uses FSD Beta
- On some roads in southeastern and northwestern Ohio, that I though would not count as highways for various reasons--designation, 45 and 55 mph speed limits, even cross roads (!)--it also used NoA.
- In northern Indiana, they have this strange type of road that is 70mph, but has stop lights and other cross roads that have stop signs, and it used FSB Beta on almost all of them.
On the bright side, it switched back and forth between the two very smoothly every time, and I became so comfortable with FSD Beta driving on "highways" that the only time I too over was because of poor behavior of other drivers, or inside cities (like the double-roundabout just west of the supercharger in Dublin, OH.)