Mr Pumpy comes slogging along a Thai 'B' road around mid-afternoon. Note the entrance to the Thai wat on the right of the picture (the big orange thing) and the adjacent bus stop shelter (the small orange thing). An imposing entrance like this denotes a very 'well off' wat.
The good news is that the 'B' roads all the way to ChiangMai are mostly wide, sealed, flat and carry little traffic. The bad news is that some stretches are touching on the 'boring'. Throw in a really hot day and you've got a bit of a slog along a never ending flat road leading nowhere.
However, dotted along the whole stretch at regular intervals are small Thai food and drink shops, so you'll be able to pace yourself with some Coke and company when your brain starts to act funny. Mr Pumpy's brain sometimes acts a little funny.