The reason to put up with the paperwork, the deposits and the traffic is here. Thailand rewards a driver more than almost anywhere in the region: the roads are good, fuel is cheap, and within an hour of any city the traffic thins out into something genuinely pleasurable.
The famous one is the Mae Hong Son loop — six hundred kilometres of mountain road out of Chiang Mai, and worth every one of its bends. If you have less time, the Samoeng loop gives you a morning of the same country, and the road to Pai packs the whole experience into a single afternoon. Further out there is Isaan, still the least-driven part of the country by visitors, and the Andaman coast.
Cities are the other half of this section, because most trips start in one. Driving in Bangkok is not the ordeal its reputation suggests, provided you understand when not to attempt it and how the expressway network lifts you over the worst of it.
Then the logistics: tolls, taking a vehicle to the islands, and the land borders — where the short answer for anyone in a hire car is usually no, for reasons worth knowing before you drive to the frontier.
