Why Roundabouts Are a Software Engineer's Dream
The Beauty of Roundabouts
A software engineer confesses a soft spot for roundabouts, arguing they solve intersection problems with radical simplicity. Unlike traffic lights, which need sensors that miss motorcycles and bicycles and encourage yellow-light racing, roundabouts use no electricity or active control. They also turn leftover land into art, fountains, or welcome signs. The post includes hand-picked examples from a roundabout database.
It's solving all of these problems while being radically simpler. It has no active control mechanism and consumes no electricity. It's just a static structure, sitting there doing nothing.
- propter_hoc
My best friend is a highly experienced civil engineer, specialized in designing intersections. His take on roundabouts:
- They are adored by urban planners because they look nice and you can put a statue or fountain in the middle
- They reduce T-bone collisions
However:
- Small fender benders and sideswipes are much more frequent
- They use way more area
- They work where each direction has an approximately equal amount of traffic. However, usually, one direction (north/south, say) has a larger share of the traffic. In those cases, the bulk of traffic all needs to slow down, downshift, turn a bit in one direction and then turn a bit in the other direction for the minority of traffic that's bleeding on or off the main artery. In those cases, a traffic light is better because the timing can be adjusted to the proportion of traffic from each direction (and more flexible since it can be adjusted over time).
- Finally, they're also (mostly) worse for cyclists and pedestrians.
Essentially, they have use cases, especially in small towns, and they're pretty, but they're usually not the right engineering solution.
- rusty_rick
This led me down somewhat of a rabbit hole looking at roundabouts, then to the official roundabout page from the Department of Transportation, where I couldn't believe my eyes to see that National Roundabout Week is next week: https://highways.dot.gov/safety/intersection-safety/nrw
- Bimos
I think here in China we are not super fan of roundabouts. But we got a 4-lane roundabout with traffic lights [1] and a roundabout on elevated roads with traffic lights. [2]
- teddyh
> Roundabouts come with this otherwise unused patch of land in the middle. Apparently, it has become common practice around the world to put some random art there, or a little green space, or a fountain, or a "welcome to this town" sign.
Or a dog: <https://en.wikipedia.org/w/index.php?title=Roundabout_dog&ol...>
- YuechenLi
The key disadvantage of a roundabout is that it takes up more space and is harder to setup than plopping down a couple of stop signs.
They are awesome otherwise, I do like them better for low traffic intersections though because I don't have to stop and think about if the next car is going to yield or not.