If you fancy a quick blast in  the early morning, can I suggest this run? Starting at the junction of Lat Plakhao/Kaset Navamin Road facing east, head to Navamin Road (also called Sukhapiban1) - about 7kms. Left into Navamin Road and travel about 3.5 kms to Ram Intra and turn left under the flyover. Cycle about 6 kms to the flyover and turn left into Lat Plakhao Road, continue on Lat Plakhao for about 3.5 kms and you will get back to the start.
I've just got a helmet camera and have been playing about with it; I know it's tilted over but the following video will give you a taste of it.

http://www.youtube.com/watch?v=sT8KhOSJXXI