4 ms·

Regarding roundabouts I personally find them confusing since they are not common where I live but I wonder if the main benefit of a roundabout it that the curve

by pkaye 12y ago

Regarding roundabouts I personally find them confusing since they are not common where I live but I wonder if the main benefit of a roundabout it that the curve forces people to slow down instead of gunning through a yellow/red light.

dschiptsov 12y ago
It also has a dead-simple rule - one should give way to everyone who is already on it.
- rikkus 12y ago
  In France, "almost all roundabouts give priority to the vehicles on the roundabout". That's quite terrifying when you get to one where they don't!
- vacri 12y ago
  You're also guaranteed that all traffic to watch for is coming from one side only - you don't have to watch for cross-traffic in both directions, nor people coming from the opposite direction who are turning.
- aragot 12y ago
  I wonder how's that compares with a priority-on-the-left intersection, when the diameter of the roundabout's island < 1.5m.
pinaceae 12y ago
no its because it is far easier to run a dark-yellow/red light and then hit a car vs. a roundabout where you. will. slow. down. because you see an obstacle, not seemingly open road ahead of you.
r00fus 12y ago
Roundabouts are absolutely fantastic replacements to residential stop signs. They are horrible and frustrating with multiple lanes (the one around the Arc de Triomphe can be tough to naviate) and lots of traffic, though they might still improve throughput during heavy congestion. My only accident in a rented vehicle in Europe was with a 2-lane roundabout in Manchester which had a mandatory outer-left-turn lane that the other car didn't notice - I turned left from the center lane into the side street and got sideswiped. The other drivers were also foreigners (Belgians - my UK colleagues were not surprised about that part). edit:clarity
- justin66 12y ago
  I imagine that even if roundabouts were responsible for more accidents than busy intersections, the nature of the accidents would be less dangerous. Getting t-boned is the most dangerous kind of collision you can have in a regular car and you'd have to turn the wrong way to make that happen in a roundabout.
  - gsnedders 12y ago
    The other important thing about roundabouts is you have a corner to go around. When there are crashes they are invariably lower speed.
MetallicCloud 12y ago
Having recently moved to America from Australia (specifically Canberra, which is considered the round-about capital), one of the biggest things I miss is round-abouts. They don't stop the flow of traffic like all way stop signs or traffic lights do. One of the things I really like here though that I wish Australia would adopt is being able to turn right from (almost) any traffic light while it red.
- vacri 12y ago
  I hope you mean 'left-on-red' for Australia specifically :)
- seanp2k2 12y ago
  I wonder if that also improves average fuel economy, since there is less stop-and-go with roundabouts vs traffic lights.
- tacticus 12y ago
  Actually the NT did implement the left on red stuff for a short while. Too many idiots was the final judgement. Also roundabouts work great for low volume roads but with roads with significant traffic directions basically lock out the ones they pass.
Spooky23 12y ago
Roundabouts are great for road vehicle throughput, but are death machines for pedestrians.
saraid216 12y ago
Accelerating is the main danger for cars, whether that's making them go faster or slower. The benefit of a roundabout is that your acceleration is minimal: you slow down a bit for the turn, and you speed up as you leave it, same as any other curved road. The danger of an intersection is that cars are stopping and starting at it. If a car stops unexpectedly, you have to react. If a car starts moving unexpectedly, you have to account for it. Accelerating to make it through a light before it goes red, or slamming on the brakes in order stop in time for a light, are simply well-known cases of this. This is why highways and freeways are relatively safe: you largely don't accelerate, except at onramps and offramps. Most highway accidents come from a failed overtake: you're accelerating in order to change lanes, and then decelerating to return to the lane. This is also why rubbernecking is dangerous: it's a subtle deceleration that may be missed by the person behind you. It's not actually different for anything else that moves; it's just that other moving things have lower consequences (walking, cycling) or stronger traffic control (trains are on rails; planes listen to air traffic controllers). The closest thing is boats, and boats are rarely both traveling at high speeds and in dense formations.

by pkaye 12y ago

dschiptsov 12y ago

It also has a dead-simple rule - one should give way to everyone who is already on it.

rikkus 12y ago
In France, "almost all roundabouts give priority to the vehicles on the roundabout". That's quite terrifying when you get to one where they don't!
vacri 12y ago
You're also guaranteed that all traffic to watch for is coming from one side only - you don't have to watch for cross-traffic in both directions, nor people coming from the opposite direction who are turning.
aragot 12y ago
I wonder how's that compares with a priority-on-the-left intersection, when the diameter of the roundabout's island < 1.5m.

pinaceae 12y ago

no its because it is far easier to run a dark-yellow/red light and then hit a car vs. a roundabout where you. will. slow. down. because you see an obstacle, not seemingly open road ahead of you.

r00fus 12y ago

Roundabouts are absolutely fantastic replacements to residential stop signs. They are horrible and frustrating with multiple lanes (the one around the Arc de Triomphe can be tough to naviate) and lots of traffic, though they might still improve throughput during heavy congestion. My only accident in a rented vehicle in Europe was with a 2-lane roundabout in Manchester which had a mandatory outer-left-turn lane that the other car didn't notice - I turned left from the center lane into the side street and got sideswiped. The other drivers were also foreigners (Belgians - my UK colleagues were not surprised about that part). edit:clarity

justin66 12y ago
I imagine that even if roundabouts were responsible for more accidents than busy intersections, the nature of the accidents would be less dangerous. Getting t-boned is the most dangerous kind of collision you can have in a regular car and you'd have to turn the wrong way to make that happen in a roundabout.
- gsnedders 12y ago
  The other important thing about roundabouts is you have a corner to go around. When there are crashes they are invariably lower speed.

MetallicCloud 12y ago

Having recently moved to America from Australia (specifically Canberra, which is considered the round-about capital), one of the biggest things I miss is round-abouts. They don't stop the flow of traffic like all way stop signs or traffic lights do. One of the things I really like here though that I wish Australia would adopt is being able to turn right from (almost) any traffic light while it red.

vacri 12y ago
I hope you mean 'left-on-red' for Australia specifically :)
seanp2k2 12y ago
I wonder if that also improves average fuel economy, since there is less stop-and-go with roundabouts vs traffic lights.
tacticus 12y ago
Actually the NT did implement the left on red stuff for a short while. Too many idiots was the final judgement. Also roundabouts work great for low volume roads but with roads with significant traffic directions basically lock out the ones they pass.

Spooky23 12y ago

Roundabouts are great for road vehicle throughput, but are death machines for pedestrians.

saraid216 12y ago

Accelerating is the main danger for cars, whether that's making them go faster or slower. The benefit of a roundabout is that your acceleration is minimal: you slow down a bit for the turn, and you speed up as you leave it, same as any other curved road. The danger of an intersection is that cars are stopping and starting at it. If a car stops unexpectedly, you have to react. If a car starts moving unexpectedly, you have to account for it. Accelerating to make it through a light before it goes red, or slamming on the brakes in order stop in time for a light, are simply well-known cases of this. This is why highways and freeways are relatively safe: you largely don't accelerate, except at onramps and offramps. Most highway accidents come from a failed overtake: you're accelerating in order to change lanes, and then decelerating to return to the lane. This is also why rubbernecking is dangerous: it's a subtle deceleration that may be missed by the person behind you. It's not actually different for anything else that moves; it's just that other moving things have lower consequences (walking, cycling) or stronger traffic control (trains are on rails; planes listen to air traffic controllers). The closest thing is boats, and boats are rarely both traveling at high speeds and in dense formations.