Roundabout near signalized intersection

[jakeroot]

This is how i would fix it

I like it a lot. The intersection should have been squared off to begin with.

Only thing I'd change is to allow left turns from business access road (in the bottom right of the image) onto the main road, and eliminate the left turn from the main road. A right turn slip lane in the top left of the image would supplant the missing left turn.

Alternatively, you could just make the business access road RIRO-only. The roundabout fills in the missing movements.

[JMAN_WiS&S]

This is how i would fix it

I like it a lot. The intersection should have been squared off to begin with.

Only thing I'd change is to allow left turns from business access road (in the bottom right of the image) onto the main road, and eliminate the left turn from the main road. A right turn slip lane in the top left of the image would supplant the missing left turn.

Alternatively, you could just make the business access road RIRO-only. The roundabout fills in the missing movements.

I originally thought about culdesaccing one end off and putting a regular t intersection at the lower right but decided to keep it this way and just disallow left turns from the business access road since you can easily make a u turn at the roundabout.

[JMAN_WiS&S]

How is this?

[tradephoric]

that and the fact that suburbs usually have more money to spend on infrastructure.  Having all of these roundabouts in Carmel makes traffic so much better, there are only a handful of signals left, and the ultimate goal is to have only 1 signal left in the entire city.  The only reason why the one signal won't be removed is because it is the first signal in the state of Indiana, and one of the first modern ones in the US. this is the location of the signal: https://www.google.com/maps/@39.9783909,-86.127055,3a,75y,15h,90t/data=!3m7!1e1!3m5!1sd7J_FDFsaI1Fw4JiQFn7-g!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3Dd7J_FDFsaI1Fw4JiQFn7-g%26output%3Dthumbnail%26cb_client%3Dsearch.TACTILE.gps%26thumb%3D2%26w%3D392%26h%3D106%26yaw%3D15.4735%26pitch%3D0!7i13312!8i6656

Carmel is planning to install a traffic light at the 136th Street and Keystone Parkway roundabout to ease congestion at the roundabout.  It will be hard to achieve the Mayor's goal of eliminating all traffic signals in the city (except one) if they are actively installing traffic signals at roundabouts. 

http://currentincarmel.com/traffic-light-planned-to-ease-congestion-at-136th-street-and-keystone-parkway-roundabout

One other thing.  If Mayor Jim Brainard believes so strongly that roundabouts are safer than traffic signals, why keep the first Indiana traffic signal running in his city?  Doesn't it belong in some museum on Main Street where it's no longer a danger to the fine motorists of Carmel?  I guess Jim Brainard's ideology only runs so deep.

[silverback1065]

that and the fact that suburbs usually have more money to spend on infrastructure.  Having all of these roundabouts in Carmel makes traffic so much better, there are only a handful of signals left, and the ultimate goal is to have only 1 signal left in the entire city.  The only reason why the one signal won't be removed is because it is the first signal in the state of Indiana, and one of the first modern ones in the US. this is the location of the signal: https://www.google.com/maps/@39.9783909,-86.127055,3a,75y,15h,90t/data=!3m7!1e1!3m5!1sd7J_FDFsaI1Fw4JiQFn7-g!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3Dd7J_FDFsaI1Fw4JiQFn7-g%26output%3Dthumbnail%26cb_client%3Dsearch.TACTILE.gps%26thumb%3D2%26w%3D392%26h%3D106%26yaw%3D15.4735%26pitch%3D0!7i13312!8i6656

Carmel is planning to install a traffic light at the 136th Street and Keystone Parkway roundabout to ease congestion at the roundabout.  It will be hard to achieve the Mayor's goal of eliminating all traffic signals in the city (except one) if they are actively installing traffic signals at roundabouts. 

http://currentincarmel.com/traffic-light-planned-to-ease-congestion-at-136th-street-and-keystone-parkway-roundabout

One other thing.  If Mayor Jim Brainard believes so strongly that roundabouts are safer than traffic signals, why keep the first Indiana traffic signal running in his city?  Doesn't it belong in some museum on Main Street where it's no longer a danger to the fine motorists of Carmel?  I guess Jim Brainard's ideology only runs so deep.

The original signal is in a museum, and it isn't possible to put a roundabout there it's in the center of downtown, no r/w. He doesn't understand that roundabouts aren't the solution to all problems, there are several ones that didn't make things better, it made them worse.

[jakeroot]

Carmel is planning to install a traffic light at the 136th Street and Keystone Parkway roundabout to ease congestion at the roundabout.  It will be hard to achieve the Mayor's goal of eliminating all traffic signals in the city (except one) if they are actively installing traffic signals at roundabouts.

It's only a matter of time...

[lordsutch]

The problem with signalized roundabouts in the UK isn't that they're signalized roundabouts per se. The problem is that Highways England (and their predecessors) use them to cheap out on building any sort of interchange (or build an underpowered interchange, usually some sort of roundabout-with-flyover) at traffic levels that would make a North American or German traffic engineer faint.

[silverback1065]

Carmel is planning to install a traffic light at the 136th Street and Keystone Parkway roundabout to ease congestion at the roundabout.  It will be hard to achieve the Mayor's goal of eliminating all traffic signals in the city (except one) if they are actively installing traffic signals at roundabouts.

It's only a matter of time...

That almost looks like a Turbine Square

[jakeroot]

Carmel is planning to install a traffic light at the 136th Street and Keystone Parkway roundabout to ease congestion at the roundabout.  It will be hard to achieve the Mayor's goal of eliminating all traffic signals in the city (except one) if they are actively installing traffic signals at roundabouts.

It's only a matter of time...

http://www.wesleyjohnston.com/roads/images/20111109a515culmore.jpg

That almost looks like a Turbine Square

I'm not sure what that is, but the roundabout pictured is not perfectly circular. It's sort of oval-y.

It's the A515/Culmore Rd Roundabout in County Derry, North Ireland. Here's another angle:

[silverback1065]

Carmel is planning to install a traffic light at the 136th Street and Keystone Parkway roundabout to ease congestion at the roundabout.  It will be hard to achieve the Mayor's goal of eliminating all traffic signals in the city (except one) if they are actively installing traffic signals at roundabouts.

It's only a matter of time...

http://www.wesleyjohnston.com/roads/images/20111109a515culmore.jpg

That almost looks like a Turbine Square

I'm not sure what that is, but the roundabout pictured is not perfectly circular. It's sort of oval-y.

It's the A515/Culmore Rd Roundabout in County Derry, North Ireland. Here's another angle:

A turbine square was the precusor to the roundabout, it's the last picture in the link http://www.dailymail.co.uk/news/article-2057093/Google-Earth-view-London--circa-1909.html

[cjw2001]

that and the fact that suburbs usually have more money to spend on infrastructure.  Having all of these roundabouts in Carmel makes traffic so much better, there are only a handful of signals left, and the ultimate goal is to have only 1 signal left in the entire city.  The only reason why the one signal won't be removed is because it is the first signal in the state of Indiana, and one of the first modern ones in the US. this is the location of the signal: https://www.google.com/maps/@39.9783909,-86.127055,3a,75y,15h,90t/data=!3m7!1e1!3m5!1sd7J_FDFsaI1Fw4JiQFn7-g!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3Dd7J_FDFsaI1Fw4JiQFn7-g%26output%3Dthumbnail%26cb_client%3Dsearch.TACTILE.gps%26thumb%3D2%26w%3D392%26h%3D106%26yaw%3D15.4735%26pitch%3D0!7i13312!8i6656

Carmel is planning to install a traffic light at the 136th Street and Keystone Parkway roundabout to ease congestion at the roundabout.  It will be hard to achieve the Mayor's goal of eliminating all traffic signals in the city (except one) if they are actively installing traffic signals at roundabouts. 

http://currentincarmel.com/traffic-light-planned-to-ease-congestion-at-136th-street-and-keystone-parkway-roundabout

One other thing.  If Mayor Jim Brainard believes so strongly that roundabouts are safer than traffic signals, why keep the first Indiana traffic signal running in his city?  Doesn't it belong in some museum on Main Street where it's no longer a danger to the fine motorists of Carmel?  I guess Jim Brainard's ideology only runs so deep.

These will act more like a ramp meter than a traditional traffic signal and will be to address the very specific issue of the high school traffic exiting or entering all at once and monopolizing one leg of the roundabout.  They won't be operating all the time, just when needed to provide a break so that traffic won't back up onto Keystone Parkway.  Let's wait to see how this actually works in practice before condemning it.