Driving on the islands

I have been here for a week now and the first thing that I am moved to write about is driving.  So far I have been from the northern end of North Uist down to the southern end of South Uist, a distance of some 76Km.  My work vehicle is a Peugeot van, that has surprising off road capability. (I regularly drive over the machair sand country to yards to see cattle).

The roads here have no roadside markers and most are made of tarseal that has been laid on the ground with very little cutting or filling.  The result is a very undulating road which you frequently loose into hollows and over low rises.  On top of this is the fact that most are also single lane with passing bays randomly on one side of the road or the other.

Driving is a social event on the islands, everybody waves to each other, but it is not a relaxing occupation.   As most of the roads are single lane, tarseal with passing bays as I have already said, this results in a constant long distance game of chicken. 
As you drive you scan the road as far ahead as you can; several meters up to a kilometer.  On seeing a car you carry out a rapid mental calculation.  (a), where are the passing bays between me and him, (b), at our combined approach speed which passing bay will we be closest to at point of "impact", (c), do I need to slow or speed up to meet him at the selected passing bay.  Given that you are both travelling at 80 to 100 km/hr, do not know each other and have different levels of aggression and local knowledge several outcomes are possible.

The ideal outcome is that you both meet simultaneously at a passing bay and flash past each other at a combined speed of 120Km/hr on a length of two lane road 2 to 3 car lengths long.  Less ideal outcomes involve one, or both parties stopping or even one having to backup.  Emergency stops when meeting oncoming traffic on blind corners are not uncommon, however actual crashes seem to be rare.
Doing this in the dark (after 6 pm) adds a whole additional level of complication.
The other local behaviour is to pull over into a passing bay to let a faster car behind them pass.  This works well, but apparently the tourists that come in Summer have a lot of problems with this idea.