I discovered this road soon after I got my bike back in 2007 and have returned numerous times. It was a revelation having exhausted the limited joy that Khao Yai national park offers the Bangkok based biker. It is a little further to go than Khao Yai but there is so much more to discover and enjoy. You can base yourself around Erawan national park and have a good three or four days exploring around without getting bored. This section of highway 3199 is easily missed as most traffic trudges onto the ferry (which cost 10 baht to ride one-way) and cuts off this 25+KM of road. You rarely pass a car but do have to look out for local workers tending their cattle. They (the cattle not the workers) also leave at times some slippery poo that needs to be avoided if you are pushing it.
Overall it is a great road to blow the cobwebs out of you hair/helmet and you can spend several hours going around taking ferry trips to have a rest.
There are lots more interesting places and roads to discover all around Sinakharin reservoir that I will post information on in the future.
Map of the highway 3199 section in video:
Ride carefully and always within your ability. The video shows speed (it is not completely accurate and has some inconsistencies), elevation graph, longitude and latitude, time and date, distance along the route and a squiggly line representing the road with a dot showing the current location. This video was shot in January 2016 and roads in Thailand do change over the years, a once pristine section of tarmac can degrade and likewise a bad section can be resurfaced and become as smooth as silk!
Leave a comment if you have an up to date report.
You can find excellent bike reports and information of northland Thailand over at Golden Triangle Riders