There are two main routes to reach Uthai Thani. One is via Ayutthaya, entering the province from the East, which is the shortest distance to Amphur Muang Uthai Thani. The other route goes via Suphan Buri, entering Uthai Thani province from the South, close to Ban Rai:
Route 1: From Bangkok (starting at Rangsit), take Road No. 1 & No. 32, passing Ayutthaya, Ang Thong, Sing Buri and Chai Nat. Then turn left to Uthai Thani at Km. 206 onto Road No. 333, cross the bridge spanning the Chao Phraya River and continue for 16 km until reaching Amphur Muang Uthai Thani. The total distance is only around 222 km. From here, you can continue on Road No. 333 to Ban Rai (around 65 km).
Route 2: From Bangkok (starting at Bang Bua Thong), take Road No. 340 towards Suphan Buri, then turn left onto Road No. 357 and later turn left onto Road No. 322. At Don Chedi, briefly (ca. 250 m.) follow Road No. 3038 to the left, then turn left onto Road. No. 3264. At Ban Sa Krachom, turn right onto Road No. 333. Keep following the road, passing Dan Chang, until entering Uthai Thani Province. Then, at the end of the road, one can turn left to Ban Rai (total distance around 220 km) or right to continue on Road No. 333 to Amphur Muang Uthai Thani (total distance around 285 km).
For GPS navigation:
Uthai Thani city is located at: N 15 22.867 & E 100 01.378
Ban Rai town is located at: N 15 05.171 & E 99 31.386
Have a pleasant trip!
Photo taken close to the border between Suphan Buri and Uthai Thani.