heart-stopping moments

I am not in a position to speak authoritatively on the subject, but for what it's worth, Lonely Planet consider Cambodia to have the worst road system in Asia and one of the worst in the world.  I have never seen driving like this - in Siem Reap I have seen only 1 intersection with any signalling.  Generally there are no signs and traffic proceeds in all 4 directions all the time.  The general rule is that everyone drives slowly or at mid-speed and maintains their line and they all just sort of avoid eachother.  The overriding rule, however, is that the biggest vehicle on the road outranks all comers.  Pedestrians, bicycles, motorbikes and tuk-tuks all scatter for a car - which will proceed happily down the centre of the road without deviating no matter what else is on the road.
Another point of interest is that although traffic (officially at least) proceeds on the right hand side of the road, most cars (75%+ by my reckoning) are right hand drive.....