WHICH SIDE OF THE ROAD DO THEY DRIVE
ON?
Why do some countries drive on the right and others on the
left?
Riding a horse: keep left. A right-handed person finds it easier to mount a horse from
the left side of the horse, and it would be difficult to do otherwise if wearing
a sword (on the left). Since it is
safer to mount and dismount towards the side of the road, rather than in the
middle of traffic, the horse is ridden on the left side of the road.
Also, horsemen armed with swords prefer to keep left of each other in
order that their sword arm is nearer their opponent during unfriendly encounters
and it is easier when riding on the left to offer one's right hand for a
friendly encounter.
Jousting: keep right.
Jousting knights normally held their lances in their right hands.
It is sometimes incorrectly assumed (a common error in movies) that they
approached and passed one another on the left.
In fact, jousting knights keep to the right.
The knight holds the lance in the right hand at an angle across the
horse's neck.
Leading a horse, or a horse and cart, on foot: keep right.
It appears to be a universal practice that people lead horses with the
right hand while walking on the left side of the horse.
To best control the horse and to avoid collisions between wide carts, it
is best for the person leading the horse or cart to walk between the vehicle and
oncoming traffic, thus keeping the cart or horse to the right.
This also facilitates conversations between people meeting, and it is
more comfortable for the person walking to be in the relatively firm and
unobstructed center of the road than the edge.
Vehicles pulled by more than one horse, driven from the
vehicle: keep left. In some
places, teams of horses pulling a wagon were driven by a person sitting on the
vehicle. A right-handed driver
controls the team with a whip held in the right hand, and so must sit on the far
right-hand side of the vehicle, otherwise the whip will hit the vehicle and
anyone else seated in it. From the
right-hand side of the vehicle the driver finds it easiest to maintain
separation with oncoming traffic by keeping to the left.
It is also easier to quickly turn the team to the left than to the right
if the whip is in the right hand, so it is better to keep left so that a quick
left turn can be made off or to the side of the road in case of a potential
collision.
In summary: The choice of sides seems to have
been governed by the time of introduction of these different modes of
transportation and their relative numbers.
Most often, left-side riding was the initial standard.
In areas where hand-led carts became dominant (including, presumably,
France), right-side driving was adopted. In
areas where vehicles driven from the vehicle became dominant, left-side driving
remained the norm.
The Roman Empire standard. The standard was almost certainly keep left.
There is no written record of the Roman standard, but in late 1998 the
remains of a Roman quarry were discovered at Blunsdon Ridge, near Swindon.
Ruts in the left side of the road are much deeper than the right,
indicating that fully laden carts leaving the quarry were being driven on the
left. Also, a denarius coin from
between 50 BC and 50 AD shows two horsemen riding past each other keeping to the
left side of the road.
The Napolean factor.
It is unknown when France adopted right-side driving, but it is
documented that Napoleon required the countries he conquered to conform to
French practice.
The USA. In the
early years of English colonization of North America, English driving customs
were followed and the colonies drove on the left. The colonies gradually changed to right-hand driving after
independence from England, although the northern colonies drove on the left well
into the 20th century.
Canada. Excluding French-influenced Ontario and Quebec, Canada drove on the left until the early 1920s.
Only one third of the world now drives on the left
(based on population, rather than vehicles).
The major left-side driving countries are:
