While in Thailand, the dangers of bicycling should not be understated. The main issue is the unwritten rule that smaller vehicles (motorcycles, bicycles, pedestrians) are to give way to larger vehicles (cars and trucks). There is no right of way for bicycles, or pedestrians for that matter. The second main issue is dogs. That said, the lovely climate (specifically at dawn and before dusk), and excellent condition of many roads as well as the elevation in the hills and mountains make bicycling a treat.