Modern Roundabouts for Tulsa?

[mrhaskellok]

http://www.roundabouts.net/roundabouts.html



Wiki shows a good comparison to the well hated traffic circles.
http://en.wikipedia.org/wiki/Roundabout

Ok, so we are talking about cutting emissions and saving fuel...fire away!

[Gaspar]

quote:Originally posted by mrhaskellok

http://www.roundabouts.net/roundabouts.html



Wiki shows a good comparison to the well hated traffic circles.
http://en.wikipedia.org/wiki/Roundabout

Ok, so we are talking about cutting emissions and saving fuel...fire away!

Not going to happen!  They lead to harder drugs like this:



Found mostly in Europe, Mexico, and a host of other third world countries where computer controlled lights and even power to intersections is non-existent.  

Some feel like they are "sophisticated" and a smart idea, but ask a cop or emergency services driver.  They are very dangerous.

During Heavy traffic in Costa Rica I saw an ambulance tip over in a roundabout because there was nowhere for the cars to pull over and the driver had a choice to hit a group of cars or roll the unit.

We can unload an intersection during an emergency, but a crowded roundabout becomes blocked to all traffic, going all directions.  A multi-car wreck in a single roundabout can halt several square miles of traffic, especially if there is more than one roundabout intersection in that grid.

Very, very, bad idea.

[mrhaskellok]

I haven't heard these concerns from any American communities that have built them...do you have any sources?  

I have lived near them and they seemed to flow fine.  Never had any muli-mile back ups.

[spoonbill]

quote:Originally posted by mrhaskellok

http://www.roundabouts.net/roundabouts.html



Wiki shows a good comparison to the well hated traffic circles.
http://en.wikipedia.org/wiki/Roundabout

Ok, so we are talking about cutting emissions and saving fuel...fire away!

No way Jose! They are dangerous to drivers and very dangerous to pedestrians.

You have to retrain the driving public, and excise additional land during development to make them work.  Once installed, they never really work, and for the most part, people just try to avoid them.  Even in neighborhood development they cause a problem and additional liability.

Developers (myself included) that installed them 20 years ago (because they were popular, or our wives went to Italy and told us they were popular) are still paying the price today.

Drop this one, because the liberokasis on this forum will latch on to it and push hard for roundabouts (I've found that the more outrageously idiotic the cause, the more attractive it is to the Salon crowd).

Here they come. . .

[mrhaskellok]

The fact that you said you built these 20 years means that you and I are not talking about the same thing and you are right, we are all paying for some stupid designs.  Read the links.  

[cannon_fodder]

As per my earlier post:

They appear to work well in low traffic areas or traffic flows that are heavy in one linear direction (ie. from a stadium) but fail miserably when confronted with 4 multiple lanes of traffic.  The "inside" lanes are essentially worthless as it requires crossing traffic to get to, and then within seconds crossing traffic again to exit the inside lane.

Notice all the pictures advocating roundabouts have relatively little traffic compared to any midtown intersection between 4-6pm.   From what I have read, they do very well in instances of linear traffic flow and/or low volumes, but fail otherwise:


St. Petersburg, FL is spent $2mil tearing their's out.  Though I think it is a roundabout and not a traffic circle...
http://www.sptimes.com/News/071501/TampaBay/Metro_review.shtml

[TheTed]

During the ice storm we saw that Tulsans can't even handle stop signs. I have little faith they can handle something more complex.

[MichaelBates]

By that Wikipedia definition, Tulsa has two roundabouts already -- one at Admiral and Mingo and one at 36th and Hudson.

[dbacks fan]

quote:Originally posted by mrhaskellok

I haven't heard these concerns from any American communities that have built them...do you have any sources?  

I have lived near them and they seemed to flow fine.  Never had any muli-mile back ups.

They tried this out in north Phoenix on a main street that crosses over and has on and of ramps for Interstate 17. There was a lot of resistance at first but it has worked out quite well and ADOT is considering this for some new street and freeway intersections being built. The Ideal thing is for this application they require a smaller foot print. The first ones looked odd from overhead becauset the interchange was originally going to be a clover leaf exchange, but was never completed.



This picture is a couple of year old and does not show all of the development in the area. There are several residential neghborhoods to the west of this intersection, and to the east is shopping and commercial. The east/west road is quite heavily traveled.

With the right planning they work.