Interesting article!
Here in sweden we drive on the right side since 3 september 1967.
Before that they drove on the left side. But... the cars had the steering wheel on the left side too... Buses often had it on the right side, but some of them had them in the middle and some at the left side. One bad thing with the switch-over was that the tram service was cancelled and almost every tram track were 'dismantled'. But only in Stockholm. Malmö had their trams until 1973-ish and Göteborg and Norrköping still have their trams.
By the way, on the horse time I would have had some problems. I'm not right-handed. Neither am I left-handed. I'm ambidextrous
