“Of course, you folks drive on the wrong side of the road!” This comment from a mature member of the group of Americans I was taking on a tour of Tuscany came to mind when reading of the tragic death of a teenager hit by a car with an American woman at the wheel, driving in England on the wrong side of the road. So easy to do, as I know only too well when driving in Italy. In a climate of sane international relations, she should take responsibility for her actions and face court proceedings where the tragic event took place. But that is too simple, it seems.

For some time now I have been carrying on an informal personal enquiry into historical precedents, starting from the indisputable fact that most humans are right-handed. It is why, surely, we start writing on the left side of the page? In most of the prints and photos from before, say, 1900, when motorcars started to appear on the roads. I noted that people on horseback, carriages and coaches tended to pass on the left side so that the right hand was free to wave, press the palm, brandish a sword or point a pistol. This thought reappeared when I was sitting on a balcony that overlooked a busy square in Cambodia, intrigued by the variety of vehicles from bicycles pushing, pulling or carrying loads in varyingly sized containers to mopeds, Vespas and so on doing roughly the same thing at a faster pace and so on up the scale of power and size. The criss-crossings and near confrontations were nearly always avoided, but often at the last moment by a lunge to the left leaving the right hand free to gesticulate with whatever intention in mind.

Spiral staircases are intriguing. Most have the wide tread by the outside wall assuming, I imagine, that the armed defenders would be on the upper storey to see and maybe control what is happening below on the ground. Descending, they would use the wider treads by the outer wall of the tower staircase to leave their right hand free and, once on the ground, would be wary to pass anyone unknown on the left, be it on the ground, on horseback or in a carriage.

I may be wrong, but I think that on islands that control their own coastal frontiers, the rule is usually to drive on the left. I have visited Japan where this is the case, and in Australia too, I am told.

Inevitably, in such a complex world as ours, conventions vary. Does it matter? In questions of safety perhaps it does. Returning to England from Italy I repeat silentlykeep to the left’ for the first few days, and it soon becomes automatic. It helps to find the driving wheel on the outside of the traffic lane.

Why are most languages written from right to left? It may be easier for the majority of right-handed humans to start on the left-hand side of the page, though I do not think the Etruscans were mainly left-handed – so why did they write from right to left?