This is also what I was told this week, by the customs house in chiang kong.
Motorbikes can be taken over the bridge in a pickup, 1000bt each way.
Here is a thread that started quite hostile and negative, in the end I believe buyer and seller feel happy and confident that value for money has beenbrake034 6th March 2014, 10:51 PM
Sailing past the controversial 1,285 megawatt Xayaburi Dam on the Mekong River-
The scale of this dam is huge!