Downtown Houston Freeway "Roundabout"?

[TXtoNJ]

http://www.chron.com/news/article/Here-s-a-roundabout-way-to-ease-traffic-congestion-3836900.php

Interesting idea; not sure about the logistics, though.

[kphoger]

This has also been suggested (to what degree of seriousness, I don't know) for Kansas City.

[Truvelo]

Charleroi in Belgium already has an example but I've never driven it so I don't know how well it works.

[vtk]

I think that could work, specifically if traffic enters the "circle" on the opposite side from which it exits, and the lanes are configured so that if one doesn't change lanes inside the "circle", one will exit going the same general direction one was going before entering the "circle".  Designing that would be pretty straightforward if local access weren't part of the equation.  Maybe eliminate surface ramps to and from the "circle" and just have massive ramps connecting the radials to one-way pairs that run through downtown serving as C/D roads?

[NE2]

Charleroi in Belgium already has an example but I've never driven it so I don't know how well it works.

http://fr.wikipedia.org/wiki/Ring_belge_R9

Osaka has one too (with a radial cutting through the middle).
http://ja.wikipedia.org/wiki/%E9%98%AA%E7%A5%9E%E9%AB%98%E9%80%9F1%E5%8F%B7%E7%92%B0%E7%8A%B6%E7%B7%9A
http://commons.wikimedia.org/wiki/Category:Hanshin_Expressway_Route_1_Loop_Route

[Chris]

Interesting idea. I do think I-10 through traffic should be excluded from the roundabout movement though.

[Henry]

If done right, it could be a great benefit to the downtown freeway loops across the nation. We'll see if it does.

This has also been suggested (to what degree of seriousness, I don't know) for Kansas City.

Add Charlotte to that list as well.

[Anthony_JK]

It does sound interesting....but I'm wondering how they would be able to fit such a "roundabout" within all those stack interchanges they have, such as the I-45/US 59, US 59/I-10, and I-10/I-45 interchanges.

Wouldn't double decking be a cheaper option??

[Perfxion]

They should double deck or over/under through traffic for people wanting to stay on a certain highway. Big question, if I-69 is laid over US59 through Houston, does that add to the traffic to the point they need to really double deck that highway?

[Road Hog]

Something like this could work well in Dallas using I-35E / I-30 / Central / Woodall Rogers. The only way this can work well, though, is if the circle is a continuous ribbon all the way around. If you're having to change lanes to stay on the roundabout, it adds to the congestion and defeats the purpose.

(fixed it to I-35E.)

[vtk]

If you're having to change lanes to stay on the roundabout, it adds to the congestion and defeats the purpose.

The way I imagine it, if you don't change lanes at all, you travel half the roundabout and exit going the same general direction as before (through traffic).  Change lanes to the left some, and you stay in the roundabout longer, and exit going in a direction somewhat counterclockwise from before.  Change lanes to the right some, and you are in the roundabout for a shorter time, and exit going in a direction somewhat clockwise from before.  If any high-volume movements would require excessive lane changes, then additional ramps should be added to the design to better accommodate those movements.

I think I may have to do a drawing for how this concept could be implemented on Columbus' Innerbelt, construction circa 2050, design year circa 2075...

[OCGuy81]

Interesting concept, but it seems to be an accident waiting to happen.  For example, too many people wanting to get from 45 NB to 10 WB and having to merge in a relatively short amount of space?  Then again, I'm no engineer.

With Houston's hub and spoke system, couldn't 610 basically be a large roundabout anyway? 

[NE2]

ODOT has been rebuilding Tulsa's (two-way) Inner Dispersal Loop by partly closing one direction at a time. For example, right now, the north leg is westbound only: http://www.okladot.state.ok.us/newsmedia/tulsa-idl/route.php

[rantanamo]

Something like this could work well in Dallas using I-35E / I-30 / Central / Woodall Rogers. The only way this can work well, though, is if the circle is a continuous ribbon all the way around. If you're having to change lanes to stay on the roundabout, it adds to the congestion and defeats the purpose.

(fixed it to I-35E.)

I think this would be great in Dallas.  Too bad they have already invested in the typical projects, because this might actually be a much better solution than simply rebuilding the mixmaster.

[vtk]

Decided to develop this concept for Columbus over on Fictional Highways:

When I feel the lane configuration plan has stabilized, I'll do the actual geometric design for each interchange, and post them to Redesigning Interchanges.

(Abbreviated quote; see post for more complete explanation)