Hacker News Reader

Comment by hn_throwaway_99 | Hacker News Reader

I found this really intriguing, and unfortunately can't understand the linked video in Swedish, but I'm really confused about how they did this with the huge amount of physical infrastructure that would have needed to change. After all, there are a lot of road features (e.g. many styles of ramps and turn lanes) that aren't symmetrical, so switching sides would have required a ton of construction. How did they accomplish this so quickly?

View on HN

You have received replies already, but there are at least some pieces of non symmetrical infrastructure from that era that remain.

I live in Gothenburg, where trams are still one of the major forms of public transportation. There's at least one (presumably more) stop where the trams turn around that's quite inconvenient because it's built for left side driving:

https://www.google.com/maps/@57.6780363,12.0042818,149m/data...

If you want to board a tram that's turned there and will go back north, you can't do so at the platform where passengers usually wait. You have to cross the street, since the tracks actually don't connect to the main route until after the regular passenger platform.

All in all, things like that are quite rare. I guess a lot of our infrastructure - particularly highways, was built after the switch.

It took three years of planning to accomplish. Plus it was in the 1960s when there were fewer and slower cars, fewer motorways and generally fewer explicit markings.

They were remarkably clever to realize that they needed to switch before building motorways for several decades. The costs weren’t astronomical but today they would have been.

Buses, trams etc. would also have the doors on the wrong side, so cannot just switch side one day without any planning.

And indeed, the article tells that they had to replace their trams by buses with the right doors (pun intended) in some major cities, presumably until they could fix the trams.

What actually happened in most cities was that the trams were shut down, which was really unfortunate with hindsight.

Reply on news.ycombinator.com