I found fatigue mostly depends on the other traffic. In my 2003 Volvo S60 I can do 800km [500mi] of Autobahn with virtually zero fatigue (basic cruise control

I found fatigue mostly depends on the other traffic. In my 2003 Volvo S60 I can do 800km [500mi] of Autobahn with virtually zero fatigue (basic cruise control and better seats than in my living room) -- with little traffic and mostly cruising at 110km/h [70mph] (or faster if traffic demands it). Though there is not much difference to 140km/h [87mph] besides 20% better fuel economy. Now, same car, same weather, but 50km (read: fifty) of heavy stop&go on a three lane Autobahn -> Kill me, please. I'm looking forward to my next car with adaptive CC, that should eat a lot of the stop&go stress (also on my daily commute). But - to get to the point - I don't think that Autopilot will make things much better than that, since I still need to be aware of traffic and anticipate potential stupidities committed by other drivers -- and that's what's causing most of the fatigue for me.