Cities Skylines has… weird limitations when it comes to roundabout implementations. There isn’t a specific “roundabout” road element that you can plop down, so people have to make do with faking them using various combinations of ramps and standard road segments. Without mods, those combinations have a tendency to seriously degrade intersection throughput because of the fact that traffic inside the roundabout just thinks it’s on a very tightly-curved, circular street with four T-intersections (because it technically is). The most popular way to get around that problem is by making the roundabout out of interstate lanes, weirdly enough.
Intersection design in Cities Skylines is sort of an olympic sport for some people. Interstate interchanges in particular can feature some of the most bonkers feats of ludicrous engineering I’ve ever seen.
This isn’t even terribly high on the crazy list, it’s just on the first few pages of results when searching the Steam workshop for “intersection”.
When you only look at cars, Roundabouts look good. When you factor in pedestrians and cyclists, they look awful. In particular, on a multi lane roundabout, any cyclist who wants to go more than one exit around needs to be prepared to take a very real risk of dying.
The problem I would have with most of these intersections is needing advance knowledge to navigate through it. Turning right twice to get to my LEFT turn. Turning in what seems the wrong direction to get to my exit. (I actually live near one such interchange, where you rise high in the air, curving North, but both North and Southbound lanes split up there out of sight, with the Southbound lane sharply curving back to the direction you wanted). Missing my exit, and “just going around again”, but losing track of direction and heading out the wrong way. These systems may be more efficient for a self-driving car which knows where it’s going, but they’re not intuitive to a driver encountering the intersection for the first time.
Yup. AFAIK, in all of Europe, once you are in the roundabout, you have right of way over anyone wanting to enter the roundabout.
Usually there are signs accordingly.
If cars inside the roundabout have to yield, throughput goes to hell.
Regular intersections and polite drivers create their own set of problems:
Off-topic: if you watch a film (unless it’s a really big production like a James Bond or something in that league) and you see a couple of cars getting into a situation where they might crash… if they are around 10 years old or older at the time the film was shot, but not classic vintage cars, they will crash.
