On the world of Ruquelis, I'm contemplating having cars (currently at circa 1920s levels of development and styling) having a central driving position, not because of some recent design decision, but because that is the way it has always been on that world. Most cars would be single-seaters, two seaters (driver with passenger behind), three seaters (driver between passengers) or six seaters (2 rows of 3), though other variations would exist.
Ruquelis is inhabited by humans, but there are three sexes, men, women and lilim, born in equal proportions. Men are what they sound like, as are women, while lilim are female, have batlike wings in addition to arms, taloned feet and can fly. However, the population is comprised of roughly equal numbers of men and lilim, while women comprise about an eighth to a fifth of the population, depending upon the nation, since women very rarely live beyond 30 years (most die between 9 and 30, with a mean of 21) while the other sexes have normal human lifespans.
All females are born flightless (about 2/3 of all births), while lilim differentiate from women between 6 and 9 years of age, beginning to grow wings and talons at that time, the change taking 3-4 years to complete before they can fly.
Thus, men are the usual drivers, with some women driving occasionally, while lilim seldom drive thanks to their ability to fly (and due to their different feet), and if they do get into a car, it is often as a passenger in a vehicle with a driver and at least one other flightless passenger, since most lilim are capable of flying easily with a single adult passenger or two or three child passengers, and can fly faster than it is safe for a car to be driven.
I'm currently debating the pros and cons of a central driving position with myself, and I'm not quite sure whether the pros or cons would win.
On the pro side, these cars would be fully usable in any nation, whether they favoured driving on the left (LHT) or right (RHT) side of the road. Visibility would be the same to both left and right. Tooling for car manufacturers selling to both LHT and RHT nations would be cheaper. Changing cars from centre-drive to left or right hand drive would result in existing drivers being uncomfortable with them at first, and a potential increase in accidents.
On the con side, with cars that would be mainly front-engine, rear-wheel-drive, the steering mechanism could be more complicated. Getting in and out would require that the driver cross over the passenger seat on either side. Visibility of the centre of the road would be poorer (though I seem to recall that IRL there have been nations in which the driver is on the same side as the side of the road on which they drive).
Additionally, Ruquelis is a world particularly steeped in tradition, since many people have reincarnated memories and skills, sometimes going back several lives.
Are there any particularly compelling non-subjective arguments for a 1920's tech world (as far as cars go) why a car should not be centre-drive that might outweigh the factors favouring centre-drive cars?
I'm looking for either a "No particularly compelling reason" answer or a "it would be changed because of this compelling (financial/ engineering/ safety/ other non-subjective) reason answer. It would need to be particularly compelling due to Tradition! Just 'sort of inconvenient' wouldn't really cut it.