Uh, Mike??? No one said anything about riding a full day in school zones.
I don't know where YOU ride, but even riding here in town in Clovis, NM our speed limits are as high as 45 and 55 mph - in town.
Here in the southwest and western states - we don't ride 35 mph anywhere outside of city limits. I ride a lot in the mountains in NM, AZ, CO and WY - and I can assure you your "good estimate" is flat ridiculous.
O.K. you show me how you average more than 35mph on non-Interstate roads over an 8 hour riding day. That will have to include breaks an gas stops. I was in New Mexico on vacation with a bike in 2001 and 2003. Travelled from Albuquerque to Santa Fe, Albuquerque to Roswell to Ruidoso to Las Cruzes, Ruidoso to Fort Sumner and back. All what I consider non-Interstate. No way I averaged more than 350 miles on any day with 10 hours riding.
78 BMW R100S, 90 BMW K1; 99 BMW R1100RT, 12 K1600GT