Most of the roads are comletely straight (blame the Romans?) so riding on them isn’t too bad, I did a 100 mile loop the other week entirely on the A171, A170, A169, A174 and felt safer than on a lot of the narower roads! Added bonus it’s almost impossible to get lost.
Start in Saltburn -> Skelton -> Lingdale -> A171 to Scarbrough -> A170 to Pickering -> A169 to Whitby -> A174 to Saltburn.
2000m of climbing, 100 miles, and the climbs tend to be a slog to the top folowed by a steep drop, then repeat, so there’s no rest, then on the way back from Whitby the climbs all seem to be 1in4/1in5 just as your legs are dying!