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comment by goobster
goobster  ·  2560 days ago  ·  link  ·    ·  parent  ·  post: America is now an outlier on driving deaths

Making a left in that turbo roundabout seems more finicky than it needs to be.

It seems like this is going to be more trouble for anyone that doesn't know exactly where they are going. It also only works where there are 4 potential exits. Add an exit, and the middle lane becomes a wasteland of lost tourists, wandering aimlessly... ;-)

Well ok, maybe not THAT bad! But I think in the UK the majority of the roundabouts had more than 4 exits.

Heck... maybe that's why roundabouts came up in the first place... to make it easier to join multiple roads, rather than just a crossroads...





kleinbl00  ·  2560 days ago  ·  link  ·  

I suspect, like roundabouts in general, it's maddening and/or frustrating until you use it and then you go

...oh...

And then you feel silly for getting so worked up about something that's actually really fucking effective.

veen  ·  2560 days ago  ·  link  ·  

To put some numbers behind it, the theoretical capacity for a regular roundabout is 20-25k vehicles/day, whereas the above can process up to 40k/day, mostly dependent on where the largest flows come from. (A regular intersection with traffic lights can handle between 20-35k.)

goobster  ·  2559 days ago  ·  link  ·  

Ooooh! Numbers! I love data!

Do you have numbers for similar intersections with traffic lights, or stop signs, to compare against the roundabout numbers?

veen  ·  2560 days ago  ·  link  ·  

All directions can use the heuristic 'if you go left, take the left lane, if you go right, take the right lane.' It looks harder than it actually is! You're right though, it's a solution that does not always fit the problem.

Dual-lane roundabouts usually create more confusion because people might not change lanes in time, like here: