4 ms·

> I can't fathom why the US insists on stop signs and traffic lights everywhere. A neighborhood I used to drive through on my way to work had 4 way stops sprout

> I can't fathom why the US insists on stop signs and traffic lights everywhere. A neighborhood I used to drive through on my way to work had 4 way stops sprouting up constantly. I don't mean to sound snarky or judgemental, so please understand that is not my intention... Sometimes they do this to dissuade people from commuting to work through neighborhoods. Again, I don't mean to judge, that might be the best/safest/only/etc way for you to get to work and you may not be the target of these stop signs. There is a 4 way stop in my neighborhood that is going to be converted to a traffic circle next year to keep traffic moving. Waze currently routes a lot of traffic through our neighborhood when the freeway is backed up at rush hour. I think the traffic circle might make it worse since the "pain" of the 4 way stops will be gone so the backup might be gone but the traffic volume would be higher. I might be wrong, but I'm curious to see the final effect. I'm also not sure which is worse for overall health and safety -- the higher volume with no bottleneck or lower volume with a bottleneck.

takk309 7y ago
I may be being a bit of a pedant but do you mean roundabout? Traffic circles and roundabouts are different. A traffic circle, in the modern sense, does not have much horizontal deflection on the entering legs. The diameter is also smaller and there is not a truck apron. A roundabout on the other hand has some form of horizontal deflection and a truck apron. Often times a traffic circle can be installed by placing a round bit of curbing in the center of an existing intersection. These are great in low volume low speed applications such as neighborhoods. Traffic circles have a much lower capacity than a roundabout due to the low travel speeds. Again, sorry for being a pedant but I am a traffic engineer and the distinction between these two traffic control devices matters. Here is a link to roundabout specific information from the Federal Highways Administration https://safety.fhwa.dot.gov/intersection/innovative/roundabouts/ https://safety.fhwa.dot.gov/intersection/innovative/roundabo...
- bluntfang 7y ago
  >the distinction between these two traffic control devices matters To reflect your pedantic efforts: does it matter in _this_ discussion? Colloquially they are the same thing when not having a technical discussion.
- souprock 7y ago
  Traffic circles and roundabouts don't exist. Those things are all called rotaries. The tiny ones are inherently defective, especially for large vehicles. The larger rotaries can be nice, especially when installed above a freeway that intersects with low-volume roads, but they are too costly unless the land is very cheap. A decent use of a rotary is in Massachusetts where Drum Hill Road and Old Westford Road meet US 4 (North Road) right over top of Interstate 3. It's a 6-way intersection, with the elevated rotary helping to deal with the high speed of Interstate 3. The intersection used to be even nicer, free of traffic lights and with a smooth elliptical shape, prior to Interstate 3 being widened.
  - selimthegrim 7y ago
    Surely you mean US 3 and MA 4
  - takk309 7y ago
    A rotary has higher speeds and entering traffic gets the right-of-way. They are very different from a roundabout.
- bonestamp2 7y ago
  You are correct, it is technically a roundabout. $1.3 million for a single lane roundabout with a raised median. Does that cost sound reasonable?
  - takk309 7y ago
    It really depends on the agency building the roundabout and the property values at the intersection. For example a rural intersect near me just got a single lane roundabout and it cost $3.2 million. The agency building it prefer a lot of concrete over asphalt. Other states can build them for less if they use asphalt.
rconti 7y ago
No worries, and I understand your concern. Yes, there is a neighborhood arterial (2, actually) as the only routes to the office park. To be fair, they're arterials with 30mph speed limits (no driveways on them), which, frankly, makes the stop signs all the more galling. (they were specifically called out in a traffic study of that neighborhood as the WRONG way to control traffic on that type of road).

takk309 7y ago

I may be being a bit of a pedant but do you mean roundabout? Traffic circles and roundabouts are different. A traffic circle, in the modern sense, does not have much horizontal deflection on the entering legs. The diameter is also smaller and there is not a truck apron. A roundabout on the other hand has some form of horizontal deflection and a truck apron. Often times a traffic circle can be installed by placing a round bit of curbing in the center of an existing intersection. These are great in low volume low speed applications such as neighborhoods. Traffic circles have a much lower capacity than a roundabout due to the low travel speeds. Again, sorry for being a pedant but I am a traffic engineer and the distinction between these two traffic control devices matters. Here is a link to roundabout specific information from the Federal Highways Administration https://safety.fhwa.dot.gov/intersection/innovative/roundabouts/ https://safety.fhwa.dot.gov/intersection/innovative/roundabo...

bluntfang 7y ago
>the distinction between these two traffic control devices matters To reflect your pedantic efforts: does it matter in _this_ discussion? Colloquially they are the same thing when not having a technical discussion.
souprock 7y ago
Traffic circles and roundabouts don't exist. Those things are all called rotaries. The tiny ones are inherently defective, especially for large vehicles. The larger rotaries can be nice, especially when installed above a freeway that intersects with low-volume roads, but they are too costly unless the land is very cheap. A decent use of a rotary is in Massachusetts where Drum Hill Road and Old Westford Road meet US 4 (North Road) right over top of Interstate 3. It's a 6-way intersection, with the elevated rotary helping to deal with the high speed of Interstate 3. The intersection used to be even nicer, free of traffic lights and with a smooth elliptical shape, prior to Interstate 3 being widened.
- selimthegrim 7y ago
  Surely you mean US 3 and MA 4
- takk309 7y ago
  A rotary has higher speeds and entering traffic gets the right-of-way. They are very different from a roundabout.
bonestamp2 7y ago
You are correct, it is technically a roundabout. $1.3 million for a single lane roundabout with a raised median. Does that cost sound reasonable?
- takk309 7y ago
  It really depends on the agency building the roundabout and the property values at the intersection. For example a rural intersect near me just got a single lane roundabout and it cost $3.2 million. The agency building it prefer a lot of concrete over asphalt. Other states can build them for less if they use asphalt.

rconti 7y ago

No worries, and I understand your concern. Yes, there is a neighborhood arterial (2, actually) as the only routes to the office park. To be fair, they're arterials with 30mph speed limits (no driveways on them), which, frankly, makes the stop signs all the more galling. (they were specifically called out in a traffic study of that neighborhood as the WRONG way to control traffic on that type of road).