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Which is ironic because roundabouts were initially sold as solutions making road intersections more safe, not as means of increasing throughput. The reduction o

Which is ironic because roundabouts were initially sold as solutions making road intersections more safe, not as means of increasing throughput. The reduction of crashed and injuries comes from decreased speed of cars. So obviously it's at a cost of throughput

andrewflnr 3y ago
It's only obvious if you're confusing throughput with latency. Also, you're comparing with stoplights, a system where you often stop dead rather than slow down. So it's obvious to me that increasing safety and througput at the same time is very plausible.
- pi-e-sigma 3y ago
  That's indeed so obvious that in Europe there is a new trend of reverting roundabouts back to standard intersections. Because in reality roundabouts slow everything down to unbearable speed. EDIT: you make a mistake assuming that just because traffic going through a roundabout doesn't completely stop that it automatically means that the throughput is higher than a stop-and-go traffic through normal intersection. And also assume that traffic going through a roundabout never stops, which is simply not lined up with the observable reality
  - andrewflnr 3y ago
    I'm not making any such assumptions. You're the one making bold claims about "obvious" causality, while I'm just saying it's not really obvious either way (and if you think that's a lie, check my phrasing more carefully).
    - pi-e-sigma 3y ago
      Your initial claim: >So it's obvious to me that increasing safety and througput at the same time is very plausible. Your current claim: >I'm not making any such assumptions If you don't make any assumption how can you even say that something is 'very plausible'? Based on what exactly then? Gut feeling? If so then it's not 'plausible', it's just your gut feeling dressed in nice wording
      - andrewflnr 3y ago
        > check my phrasing more carefully "plausible" is not nearly as definite as "safety obviously comes at a cost of throughput", and is furthermore not a statement about causality, but a claim that improving safety and througput don't immediately rule each other out; a contradiction needs a strong proof, since so many things that appear contradictory turn out to be compatible with enough imagination. Absent that proof, compatibility is plausible. But sure, maybe I should have put air quotes around "obvious", since there's no real obvious correct conclusions here. "Just your gut feeling dressed in nice wording" is another great way to describe your initial claim about roundabouts, too, which was my main point to start with.
        pi-e-sigma 3y ago
        I provided reasons why I think throughput would be affected, such as the fact that roundabout is a curved road explicitly designed to slow traffic down. With slowed down traffic approaching from all directions it is reasonable, hence plausible, to assume that the throughput would be negatively affected. You instead just reply with some sophistry and don't bring any arguments grounded in reality. Especially your statement, that 'absent that proof, compatibility is plausible' just highlights that you don't even know what 'plausible' actually means because something can't be plausible by default, without any reasoning or facts backing it up
        andrewflnr 3y ago
        I note you've moved the goalposts from "obvious" causality to "reasonable, therefore plausible" causality. Still, I continue to find your attempt at "grounding" unconvincing. The mere fact that cars must slow for a roundabout does not automatically make it lower throughput than one where they have to actually stop for some unspecified interval. Speaking of specification, if I was trying to be grounded, I would assume that which system has higher throughput depends on the implementation details and situation, notably the timing of the lights and how much traffic is naturally on the given road. Details matter. You've been attempting to make generalizations irrespective of any of those details, and I'm saying they're not justified, or at best need much stronger evidence. But sure, I'm the sophist here. I'd ask you for "facts" to back up your claim, but you've already walked it back, so I guess I'm done.
yurishimo 3y ago
Both can be true. If you have cars coming from all directions that can easily merge with each other, it makes sense that throughput would also be increased since the other 3 directions don't need to stop to make a left turn from any direction. Safety might be factor number 1, but a roundabout will sustain higher traffic loads than a traffic light, assuming that all directions are being fed with equal amounts of vehicles. For this reason, a lot of arterial roads in NL still use traffic lights because they prioritize traffic moving in a single dimension (x or y, but not both). The smaller intersecting roads need to wait on the light during rush hour since the priority is traffic on the larger road. When two roads of a similar size/traffic mix, a roundabout can be used to facilitate changing directions. Here is an example near Eindhoven in the south part of the country: https://maps.app.goo.gl/SYMnP9jwNEj1ytx2A https://maps.app.goo.gl/SYMnP9jwNEj1ytx2A There's also a fairly large roundabout about 1-2km north of that intersection if you're interested. It's increased size provides more throughput and slows down drivers coming from the highway and allows a smooth transition down to the lower speed allowed within the city limits.

andrewflnr 3y ago

It's only obvious if you're confusing throughput with latency. Also, you're comparing with stoplights, a system where you often stop dead rather than slow down. So it's obvious to me that increasing safety and througput at the same time is very plausible.

pi-e-sigma 3y ago
That's indeed so obvious that in Europe there is a new trend of reverting roundabouts back to standard intersections. Because in reality roundabouts slow everything down to unbearable speed. EDIT: you make a mistake assuming that just because traffic going through a roundabout doesn't completely stop that it automatically means that the throughput is higher than a stop-and-go traffic through normal intersection. And also assume that traffic going through a roundabout never stops, which is simply not lined up with the observable reality
- andrewflnr 3y ago
  I'm not making any such assumptions. You're the one making bold claims about "obvious" causality, while I'm just saying it's not really obvious either way (and if you think that's a lie, check my phrasing more carefully).
  - pi-e-sigma 3y ago
    Your initial claim: >So it's obvious to me that increasing safety and througput at the same time is very plausible. Your current claim: >I'm not making any such assumptions If you don't make any assumption how can you even say that something is 'very plausible'? Based on what exactly then? Gut feeling? If so then it's not 'plausible', it's just your gut feeling dressed in nice wording
    - andrewflnr 3y ago
      > check my phrasing more carefully "plausible" is not nearly as definite as "safety obviously comes at a cost of throughput", and is furthermore not a statement about causality, but a claim that improving safety and througput don't immediately rule each other out; a contradiction needs a strong proof, since so many things that appear contradictory turn out to be compatible with enough imagination. Absent that proof, compatibility is plausible. But sure, maybe I should have put air quotes around "obvious", since there's no real obvious correct conclusions here. "Just your gut feeling dressed in nice wording" is another great way to describe your initial claim about roundabouts, too, which was my main point to start with.
      - pi-e-sigma 3y ago
        I provided reasons why I think throughput would be affected, such as the fact that roundabout is a curved road explicitly designed to slow traffic down. With slowed down traffic approaching from all directions it is reasonable, hence plausible, to assume that the throughput would be negatively affected. You instead just reply with some sophistry and don't bring any arguments grounded in reality. Especially your statement, that 'absent that proof, compatibility is plausible' just highlights that you don't even know what 'plausible' actually means because something can't be plausible by default, without any reasoning or facts backing it up
        andrewflnr 3y ago
        I note you've moved the goalposts from "obvious" causality to "reasonable, therefore plausible" causality. Still, I continue to find your attempt at "grounding" unconvincing. The mere fact that cars must slow for a roundabout does not automatically make it lower throughput than one where they have to actually stop for some unspecified interval. Speaking of specification, if I was trying to be grounded, I would assume that which system has higher throughput depends on the implementation details and situation, notably the timing of the lights and how much traffic is naturally on the given road. Details matter. You've been attempting to make generalizations irrespective of any of those details, and I'm saying they're not justified, or at best need much stronger evidence. But sure, I'm the sophist here. I'd ask you for "facts" to back up your claim, but you've already walked it back, so I guess I'm done.

yurishimo 3y ago

Both can be true. If you have cars coming from all directions that can easily merge with each other, it makes sense that throughput would also be increased since the other 3 directions don't need to stop to make a left turn from any direction. Safety might be factor number 1, but a roundabout will sustain higher traffic loads than a traffic light, assuming that all directions are being fed with equal amounts of vehicles. For this reason, a lot of arterial roads in NL still use traffic lights because they prioritize traffic moving in a single dimension (x or y, but not both). The smaller intersecting roads need to wait on the light during rush hour since the priority is traffic on the larger road. When two roads of a similar size/traffic mix, a roundabout can be used to facilitate changing directions. Here is an example near Eindhoven in the south part of the country: https://maps.app.goo.gl/SYMnP9jwNEj1ytx2A https://maps.app.goo.gl/SYMnP9jwNEj1ytx2A There's also a fairly large roundabout about 1-2km north of that intersection if you're interested. It's increased size provides more throughput and slows down drivers coming from the highway and allows a smooth transition down to the lower speed allowed within the city limits.