There remain 4 mini ferry crossings for the small rivers which cross the road, but there is a new toll bridge (opened April 2002) at Koh Kong. The ferries negotiated their services in Thai Baht, and accepted this currency and, like elsewhere in Cambodia, US$. Doubtless, Cambodian Riel would also be accepted.
As the road is unsealed, it will suffer during the annual rain-season. This was witnessed in a minor way during a torrential thunder storm while I was travelling it. It was heavily ponded in sections during the storm, and washed-out in others afterwards.
It is also annoyingly corrugated in parts.