Jump to content
Guest jwulsin

Cincinnati Roundabouts

Recommended Posts

If you could reconfigure one intersection in Cincinnati to become a roundabout, which one would you choose? I think there are many intersections which motorists have to idle at for far too long waiting for a green arrow. My first choice would be Liberty and Central Parkway. The traffic flow there is so light, but the intersection is absurdly large. A small, single-lane roundabout would allow for easy flow of traffic while making it easier and safer for pedestrians and bicyclists as well.

Share this post


Link to post
Share on other sites

If you could reconfigure one intersection in Cincinnati to become a roundabout, which one would you choose? I think there are many intersections which motorists have to idle at for far too long waiting for a green arrow. My first choice would be Liberty and Central Parkway. The traffic flow there is so light, but the intersection is absurdly large. A small, single-lane roundabout would allow for easy flow of traffic while making it easier and safer for pedestrians and bicyclists as well.

 

Wow... I've never thought about that, but they should really consider that when studying options for the Liberty Street Road Diet.

Share this post


Link to post
Share on other sites

Liberty's traffic counts range from 14,000 to 16,000. A miniature roundabout, designed for 15MPH speeds or less, wouldn't be a good choice. Even with 25% cross traffic, the maximum VPD is 14,000 with 10% left turns and 12,000 with 50% left turns. A larger roundabout that is one-lane can handle anywhere from 23,000 VPD to 20,000 VPD, with 0% to 40% left turns. Two lanes essentially double the VPD.

 

Even if it's a one-lane roundabout, there would need to be enough space for two-lanes, with the center lane being raised and marked as not a through lane - it would be used for tractor-trailers that can't negotiate the roundabout. Some good examples of this is the new KY 237 roundabouts in Boone County (http://goo.gl/maps/3nFyl).

 

Check out page 72 of http://www.fhwa.dot.gov/publications/research/safety/00067/000673.pdf. It has what I would guess would be the best fit - a roundabout with flared entrances to make pedestrian crossings safer.

Share this post


Link to post
Share on other sites

Great resource! Thanks for sharing. Where did you get the traffic numbers from? I searched (in vain) but couldn't find any numbers.

 

The roundabout at the base of the Roebling bridge is quite small, but I guess there aren't many tractor trailers that take the Roebling bridge.

Share this post


Link to post
Share on other sites

OKI has a site for those traffic numbers: traffic.oki.org

 

Hamilton County has a similar site for county roads. But OKI is a much easier interface to use.

Share this post


Link to post
Share on other sites

The City's DOTE funded and implemented a reconfiguration of the intersection at Dana Ave and Clinton Springs Ave, removing a continuous right turn lane and constructing a "mini-roundabout". I haven't had a chance to look at this in person, but from the aerial imagery it looks well-implemented and should make that intersection much more accessible to pedestrians. I'd like to see the City pursue more reconfigurations like this.

 

Streetview (before reconfiguration): https://www.google.com/maps/@39.1517463,-84.4830473,3a,75y,315.13h,76.19t/data=!3m6!1e1!3m4!1swfSJfy70cLtaKz5mz7tZNg!2e0!7i13312!8i6656

Aerial view from auditor's site: http://wedge3.hcauditor.org/view/re/0660002026690/2015/aerial_imagery_full

 

The only details I could find on this project were from a 2014 North Avondale Neighborhood Association's bulletin: http://northavondalecincinnati.net/nananewspdf/Summer%202014.pdf (page 3)

Share this post


Link to post
Share on other sites

It's nice in person. It definitely slows people shifting over to Clinton Springs from Dana which was a huge problem before. People would speed through that continuous right turn.

Share this post


Link to post
Share on other sites

Glad to hear it works in person, too!

 

Continuous turn lanes ought to be banned in the city, since they make drivers think they'll *never* need to stop to yield to pedestrians.

Share this post


Link to post
Share on other sites

I don't like that they did most of the lane channeling and narrowing with just paint and plastic bollards.  That's going to be full of gravel and other debris in no time.  They also installed some concrete curb barriers at each crosswalk, which you can see at the lower right.  I'm not sure exactly what they're supposed to do other than get clobbered by snow plows. 

Share this post


Link to post
Share on other sites

I don't like that they did most of the lane channeling and narrowing with just paint and plastic bollards.  That's going to be full of gravel and other debris in no time.  They also installed some concrete curb barriers at each crosswalk, which you can see at the lower right.  I'm not sure exactly what they're supposed to do other than get clobbered by snow plows.

 

Good point. It'd be a lot nicer if they brought in the curbs and added landscaping/hardscaping to that area. But that adds significant costs. I'm okay with the "paint-first" approach, as long as they have a way to get the street cleaners around the plastic bollards. If/when more funds are available, I'd love to see the curbs brought in. But if I were in charge of the allocation of limited funds (which I'm NOT), I'd rather see the City implement more of these with painted lane channeling, instead of doing fewer projects with moving of curbs.

 

 

Share this post


Link to post
Share on other sites

The city seems to be afraid to narrow rights of way and give property to adjacent property owners. It makes it difficult to ever "undo" a change that might not pan out, but it would be a simple, maintenance free way of elimination some of the more overbuilt roads in the city.

Share this post


Link to post
Share on other sites

Eh, if it's on the road side of the sidewalk then it's pretty much all fair game.  Besides, it's not like they're giving the land back, it just becomes grass or whatever instead of pavement, while remaining part of the public way.  They did that here a year or two ago:  https://goo.gl/maps/W5W5nZ32dFS2

 

In the case of the Monteith/Linwood bumpout, they moved the sidewalk and the new extra space is on the "house side" of the sidewalk. So, if the City ever wanted to revert it back to the old configuration, they'd have to move the sidewalk again. The property lines haven't changed, so the public right of way remains unchanged.

Share this post


Link to post
Share on other sites

Eh, if it's on the road side of the sidewalk then it's pretty much all fair game.  Besides, it's not like they're giving the land back, it just becomes grass or whatever instead of pavement, while remaining part of the public way.  They did that here a year or two ago:  https://goo.gl/maps/W5W5nZ32dFS2

 

In the case of the Monteith/Linwood bumpout, they moved the sidewalk and the new extra space is on the "house side" of the sidewalk. So, if the City ever wanted to revert it back to the old configuration, they'd have to move the sidewalk again. The property lines haven't changed, so the public right of way remains unchanged.

 

I wonder who mows that grass.

Share this post


Link to post
Share on other sites

^ Pretty sure that's the homeowner's responsibility still.  You can argue that having less pavement in front of the house is a net benefit to them, so asking them to care for it isn't really an undue burden. 

 

As for the roundabout situation, they wouldn't need to move the sidewalks at all, just build some extra legs to connect to the crosswalks. 

Share this post


Link to post
Share on other sites

This "news" is from back in October of 2016, but it shows the design of the 2-lane roundabout that will replace the current interchange where Ronald Reagan Highway terminates at Montgomery. The design is interesting in that it allows traffic exiting Ronald Reagan to SB Montgomery to bypass the roundabout. Similarly, traffic that wants to merge onto Ronald Reagan from SB Montgomery will bypass the roundabout. I'm not clear on where the pedestrian crossings will be. OKI has provided $6 million of the total $8.6 million budget. The project is scheduled to be constructed by ODOT in 2020.

 

http://www.montgomeryohio.org/oki-awards-6-million-grant-for-interchange-modification-at-ronald-reagan-highway-and-montgomery-road/

http://www.cincinnati.com/story/news/local/montgomery/2016/10/17/montgomery-gets-grant-roundabout/92305918/

 

 

Share this post


Link to post
Share on other sites

^ I wonder what the reason is to have those two ramps instead of just having the right-turn traffic use the rightmost lane of the roundabout. The ramps create some big, awkward, unusable islands.

 

Share this post


Link to post
Share on other sites

^ Because fuck pedestrians that's why.  The right-turn bypass lanes allow vehicle traffic to not queue, but it's also much more dangerous for pedestrians because motorists aren't expecting to have to yield and they're not deflected by the geometry of the circle.  With Moeller High School just a stone's throw away that's a pretty glaring conflict. 

Share this post


Link to post
Share on other sites

The decision to eliminate an existing grade-separated interchange and replace it with a roundabout seems odd, and I'm somewhat surprised ODOT supports it. I guess the interchange was originally built because the Ronald Reagan Highway was going to continue east to reach I-275, but then Indian Hill blocked that plan. So there's really no need for the interchange to exist now since Montgomery Road is the end of the highway.

Share this post


Link to post
Share on other sites

^Yeah - agreed. I'd definitely prefer getting rid of those dedicated lanes. I like your idea of simply using the right-most lane for right-turn traffic. It seems like that would be better at slowing traffic while still being sufficient to allow for smooth traffic flow (at most times of day). But I bet the folks at ODOT disagree and want to keep as much capacity as possible.

Share this post


Link to post
Share on other sites

I assume this is part of a land grab for the proposed development near this intersection by Griewe/Great Traditions/North American/Sibcy Cline etc...

 

http://www.bizjournals.com/cincinnati/news/2015/10/12/first-look-developers-show-off-plans-for-100m.html

 

Could be wrong, but money is the only reason I can see ODOT wanting to eliminate these ramps.

Share this post


Link to post
Share on other sites

^You make it sound nefarious, but the city of Montgomery was clear that a big motivation for this project is to open up extra land for that development. By removing the "half cloverleaf" on the east side of Montgomery Rd, it adds nearly 8 acres of developable land to what was initially 11 acres. Going from 11 to almost 20 acres means more housing units, more density, and more tax revenue, which is a win all around for the community.

Share this post


Link to post
Share on other sites

ODOT is probably happy to be rid of a bridge that serves little useful purpose but still needs to be maintained like any other.  It was built in 1968 and while it did get a major rehab in 2000, I'm sure it's still a maintenance concern.

Share this post


Link to post
Share on other sites

^ Because F**k pedestrians that's why.  The right-turn bypass lanes allow vehicle traffic to not queue, but it's also much more dangerous for pedestrians because motorists aren't expecting to have to yield and they're not deflected by the geometry of the circle.  With Moeller High School just a stone's throw away that's a pretty glaring conflict. 

 

But at a roundabout, if the approaching lane were marked as right turn only at the same point as in the proposed plan, traffic wouldn't queue. They could keep the long merge lane at the onramp, I just don't see how the ramp being pulled back from the roundabout is affecting the traffic flow at all. If it were pulled up tight to the roundabout, and separated with either striping, bollards, or even jersey barrier, it seems to me like it would function the same way. The islands don't seem to provide any benefit to cars, but adversely affect pedestrians (though still an improvement over the current setup).

Share this post


Link to post
Share on other sites

Didn't mean to sound nefarious, and I'm a fan of development in most cases. I used to travel through this interchange every day and this will really simplify things. I just wish transportation agencies would take on projects that improve traffic calming and reduce wasteful ramps even when there aren't developers pushing it. For instance the liberty street narrowing will allow extra developable land too, But if there aren't big name developers I just wonder if that will happen too.

 

On a side note, the new roundabout in Newport at the entrance from Covington has these continuous right turns too.

Share this post


Link to post
Share on other sites

There are ways to build roundabouts to slow traffic and reduce its negative effects on pedestrians. A roundabout like this does not do that.


“All truly great thoughts are conceived while walking.”
-Friedrich Nietzsche

Share this post


Link to post
Share on other sites

There are ways to build roundabouts to slow traffic and reduce its negative effects on pedestrians. A roundabout like this does not do that.

 

There aren't any pedestrians in this area.  Maybe some joggers, but nobody actually walking because they have to, despite the cutesy downtown. 

Share this post


Link to post
Share on other sites

There aren't any pedestrians in this area.  Maybe some joggers, but nobody actually walking because they have to, despite the cutesy downtown.

 

This is a good point. Most of the Moeller kids come from either the Madeira area or the Loveland area and just drive. There are almost no pedestrians around the school. And downtown Montgomery attracts a much older crowd; one which does not walk around down there.

Share this post


Link to post
Share on other sites

There are ways to build roundabouts to slow traffic and reduce its negative effects on pedestrians. A roundabout like this does not do that.

 

There aren't any pedestrians in this area.  Maybe some joggers, but nobody actually walking because they have to, despite the cutesy downtown.

 

I grew up around there and your assessment is correct. But I don't understand your defeatism. The answer to this situation is to *add* sidewalks (much of Montgomery Rd doesn't have sidewalks) and slow traffic. It is not inconceivable that a family would want to live in this new development and have their kids go to Moeller or All Saints. That should be encouraged by ensuring safe pedestrian crossings (as should be standard on all streets). Our region has very few opportunities to build new, mid-density housing within walking distance of a school. The developers want this project to have all parking be structured, limiting any surface parking to make it as walkable as possible.

Share this post


Link to post
Share on other sites

Right, the goal is to build a new urbanist development to replace to car dealership and highway ramps that are being eliminated. So there will be a lot more pedestrians around there soon.

Share this post


Link to post
Share on other sites

Indeed, the attitude should be that if walking is difficult it should be made easier, not just concede to letting it get worse.  That bit of Montgomery Road has the potential to actually be kind of nice (it's similar to Kenwood Road north of the mall).  Even if there isn't much foot traffic to Moeller, I'll bet there's still some, and removing the interchange would make it more palatable to anyone living north of Reagan and west of Montgomery Road.  Plus there's the Brookdale senior housing and Montgomery Station offices that would benefit from a walkable connection to downtown Montgomery. 

Share this post


Link to post
Share on other sites

Cross posted from the Northside News thread about a potential roundabout at Knowlton's Corner:

https://www.urbanohio.com/forum2/index.php/topic,9040.msg873070.html#msg873070

 

Vice Mayor David Mann will be holding a press conference tomorrow where he will announce his support for a plan to turn Knowlton's Corner (the intersection of Hamilton, Spring Grove, Hoffner, Ludlow, and old Ludlow) into a roundabout. According to a graphic he sent out, Old Ludlow might also be turned into a pedestrian only street.

 

I think this is a really good idea. Actually, the same idea popped into my head earlier this summer while I was taking some aerial photos of that intersection:

 

36948082211_ecc65536f3_h.jpg

 

36948068671_8ec2fbb59e_h.jpg

 

As you can see, there is plenty of room to make the intersection into a roundabout. Hopefully this would also encourage redevelopment of the BP and White Castle sites into something more pedestrian friendly in the future.

 

My biggest concern here is that ODOT might oppose this plan since Hamilton Avenue carries a state route. A Northside community advocate told me that any effort to do traffic calming on Hamilton Avenue in the past has been met with opposition from ODOT.

Share this post


Link to post
Share on other sites

Would the MLK/Jefferson/Vine intersection be a good candidate for conversion to roundabout? It's such a mess currently with so many slip lanes. I think (though I'm not sure, and I'm not a traffic engineer) that a well-designed roundabout could make the intersection significantly less scary for pedestrians, while still maintaining ODOT's (extremely frustrating) insistence on never reducing car-capacity. 

 

 

 

 

Share this post


Link to post
Share on other sites

From a traffic engineering by-the-book AASHTO standpoint, a roundabout actually isn't a great way to resolve complicated intersections, because tight angles preclude proper geometry without drastically increasing the radius of the circle and/or restricting right turns and truck movements.  Beyond that though, my guess is that objections would be more about the slope of the land and inability of ambulances to preempt signals and blast through the intersection.  Also, I think that intersection is just too high-capacity for either the city or state DOT to entertain such a solution.  There seems to be a lot of push back against multi-lane roundabouts due to confusing right-of-way when exiting and a perpetual confusion among the general public about just what yield means.  Instead, they seem to prefer "turbo" designs that fling exit lanes out in more of a spiral fashion than a circle (such as you see in the two new 3rd Street roundabouts in Newport), and which also pinch down to just one lane at some point.   

 

https://www.google.com/maps/@39.3137256,-84.2992925,184m/data=!3m1!1e3

Capture.PNG

Share this post


Link to post
Share on other sites
43 minutes ago, jwulsin said:

Would the MLK/Jefferson/Vine intersection be a good candidate for conversion to roundabout? It's such a mess currently with so many slip lanes. I think (though I'm not sure, and I'm not a traffic engineer) that a well-designed roundabout could make the intersection significantly less scary for pedestrians, while still maintaining ODOT's (extremely frustrating) insistence on never reducing car-capacity. 

 

This might sound counterintuitive, but I think the only realistic way to fix that intersection is to grade separate it. The way it is configured now, you have the Vine-Jefferson/MLK intersection itself plus all of the additional slip ramps that create two additional intersections -- so you have three separate intersections for one road crossing. If you had Jefferson-Vine pass underneath MLK, you would actually be able to make MLK more pedestrian friendly by eliminating one of the three intersections, and thru traffic would also benefit from not having to stop at that light.

  • Like 1

Share this post


Link to post
Share on other sites
46 minutes ago, taestell said:

 

This might sound counterintuitive, but I think the only realistic way to fix that intersection is to grade separate it. The way it is configured now, you have the Vine-Jefferson/MLK intersection itself plus all of the additional slip ramps that create two additional intersections -- so you have three separate intersections for one road crossing. If you had Jefferson-Vine pass underneath MLK, you would actually be able to make MLK more pedestrian friendly by eliminating one of the three intersections, and thru traffic would also benefit from not having to stop at that light.

 

Indeed, I think even Jake has proposed this in the past.  Since MLK climbs pretty steeply on both sides to reach this intersection, it would be a simple feat to leave Vine/Jefferson where it is and have MLK go underneath.  You could then just connect Short Vine across Vine/Jefferson to a new entrance to the EPA with a simple 4-way intersection, or make THAT the roundabout.  Then just put a jug handle somewhere in the EPA's massive useless lawn to connect Vine with MLK, or don't, and make people use Goodman/Eden/University

  • Like 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...