The GT Rider map label this trail as something like "Impassable in Rainy Season - Bikes only" but we could complete the journey in about 5 hours (in July 2013). There is a challenging river crossing thought. For 50,000 Kips / bike, the boat guy will help you to cross this river. Not really reassuring as the boat wasn't perfectly stable. A great shortcut to avoid a lengthy section of the Phongsavanh - Sam Neua road.