Rte 1095 which connects Pai with Mae Hong Son (50 km as the crow flies, but approximately 110 km by road) and Chiang Mai (135 km) is a very scenic route through the mountains which takes several hours (but is worth it). It's a steep and winding drive, with 762 curves between Chiang Mai and Pai, so take a plastic bag and some motion-sickness pills if you need them.