On a recent three month stay in Thailand, myself and two friends drove up to Chiang Mai from Pattaya. It was an impromptu trip so we thought we'd just play it by ear as far as accomodation went. We thought we'd split the journey to Chiang Mai by stopping somewhere after about 5 hours drive but could not find any hotels in the towns along the way. We ended up driving to Tak and finding quite a large international hotel there, which is surprising, because from what I saw, Tak doesn't have a lot going for it other than being on the river.
Coming back we had the same problem. We drove back a different route via Uttaradit and could not find hotels anywhere along the way, so ended up doing the whole trip non-stop to Pattaya, a gruelling 14 hours.
Now there well may be hotels in some of these small towns and certainly a Lonely Planet guide might have helped, but they certainly don't hang neon signs outside. I might add that we were only looking for small, cheap local hotels, not Hyatts or Hiltons. Anyone else had a problem finding overnight accomodation in Thailand?