I used to live off of a busy roundabout in a place that makes heavy heavy use of roundabouts (almost no four-way stops). It felt dangerous as fuck honestly. The crosswalks are a little "downstream" of the true circle, where cars have already begun to exit. Frequently (saw this a few times myself) a car would stop for a pedestrian and then get rear-ended by another car focused on exiting the roundabout.
This was not the US so unfamiliarity with roundabouts can't be blamed. They were the norm there.
Just as with yield signs you should be able to stop in time when needed.
I mean, yes, they are driving too fast. Given that drivers do drive too fast, it's a bad place for a crosswalk.
Alternating two way stops (n/s at intersection one, e/w at intersection two) seems like maybe an ok way to reduce the problem by half at little to no cost?
See the city of Nantes in France (roundabout’s paradise), navigating the intersections is horrible. In a few parts of town they even have double mini roundabouts. The only reasonable explanation I found is “security by confusion” : if you have no idea how to drive through the intersection, you’re more likely to slow down. Well it doesn’t make the intersection really safer.
Basically they recommend 28m diameter if you are going to have a central island, otherwise it should be a mini-roundabout (capable of being driven over)
True for stop signs... and any other traffic control solution in existence, frankly. Yielded merges are the most obvious form of specifically unbroken traffic flow that requires the same.
> They are also designed to reduce the amount of time any given vehicle has to actually stop if there is no reason to.
So it works like a yield. That's a good thing because it reduces congestion.
> This varies based on left/right side driving countries.
There are much bigger issues resulting from switching between left- and right-side driving standards which don't have anything to do with roundabouts, so this doesn't say anything about roundabouts so much as the difference in standards.
> Lights for pedestrians might help, but then the benefit of continual traffic flow is reduced.
Comes with the territory, and is also true of every other traffic control solution in existence. The complete solution to this is to completely separate pedestrian and vehicular traffic, which is also not limited to roundabouts.
It sounds like you don't have a problem with roundabouts so much as traffic control per se, if you believe these to be reasons not to implement roundabouts.
> True for stop signs...
Not really. Stop signs make you stop first, before needing to look around, after which you continue. There's no "direction of travel" when you've stopped; you're not traveling when you've stopped. Meaning you can focus on one thing at a time, unlike with a roundabout.
I'm pretty sure "the only factor that determines intersection safety is division of attention" was not a stance I was taking (when is an event ever a function of just 1 variable in the real world?), but if you'd prefer to take a swipe at me regardless, it would be nice if you could make your response constructive and actually link to some studies that show I said something contrary to reality, if you're well-studied in traffic flow.
Hopefully my reply clarified for you what my earlier point was, even if you think the point was wrong.
"Well-studied", no, I would not claim that. I follow the zeitgeist of urban planners as they discuss topics like this on the fora in which they congregate. I read some of the studies they post and discuss, and I have picked up on some of the memes present in that community. Something that comes up again and again and again and again (and which is immediately apparent upon reading the research) is the primacy of roundabouts for intersections, because they are the safest of the popular options and less prone to congestion than stop signs, stop lights, etc. Even when they do get congested, the outcomes are better for everyone on average, since everyone waits a similar amount of time compared to the asymmetry of e.g. intersections with stoplights. One common pitfall in thinking about these things is only thinking about individual wait times in a subjective sense, and not aggregate wait times in a systemic sense. The latter perspective provides much clarity.
Here, I did your Googling for you. Where do I send the invoice?