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Re: [New Page] Median U-turn intersection

PostPosted: Sat Mar 22, 2014 7:26 pm
by davielde
I made some substantial edits to the page but left the section on the Michigan wiki alone. The latest working draft can be found in my profile. If there is anything in this thread that I left out, let me know or feel free to edit as needed:
Michigan left

I changed the page under the assumption that we would have a separate page altogether for J-turn/RCUT/Superstreet (as J-turn with numerous redirects). I could probably start working on that this coming week too if everyone is okay with that.

Re: [New Page] Median U-turn intersection

PostPosted: Tue May 27, 2014 8:01 pm
by davielde
Request for Comments:

Regardless of how these end up being incorporated into a broader page like JSG, here are some updates for MUTI as well as an additional paragraph about RCUT and also Displaced Left Turns (DLT). Rather than repeat a lot of the same information from MUTI, the RCUT guidance assumes basic knowledge of how the MUTI treatment works since they're somewhat related. I have not tried to tackle jughandles.

  1. Median U-Turn Intersection (MUTI)
  2. Restricted Crossing U-Turn (RCUT)
  3. Displaced Left Turn (DLT)

Re: [New Page] Median U-turn intersection

PostPosted: Fri May 30, 2014 1:21 pm
by davielde
sketch wrote:BTW, "Between 1 and 44 degrees" in the DLT page should be changed to "Between 1 and 43 degrees" due to a recently-discovered imprecision in Junction Angle Info — "44" can mean either <44.5 (stay) or >44.5 (turn) by Waze.

The change has been made.

Re: [New Page] Median U-turn intersection

PostPosted: Wed Apr 09, 2014 7:26 am
by GizmoGuy411
I really feel that "Michigan Left" is the wrong name for an article name for the US and even for Michigan.

When I helped David do the initial research, I found the MUTI was the most universal term that would encompass the various similar intersections.

However after skimming these documents again, I feel the best term is "Alternative Intersections".

The MUT or MUTI is a type of Alternative Intersection.
The Michigan Ledt is a type of MUTI.
While other intesections may also be MUTIs they are a subset of Alternative Intersections.

Due to the specific connector naming that sketch has mentioned, a Michigan Left is a specialized MUTI, but not all MUTIs are Michigan Lefts.

While I have no problem with making the Mich Left more prominent within the article, I do not feel it is appropriate as a title.

While Wikipedia prominently describes the Michigan Left, it is not used universally around the US, let alone around the world. The Michigan Left probably has more recognition because it has been around since 1960.

A few links found during the initial research that support MUTI:

Although the FHWA mentions Michigan Lefts, from that point on they refer to the intersections the Median U-Turn Intersections:
[code-"Federal Highway Administraion"]The median U-turn (MUT) intersection, which is also referred to as Michigan lefts, has been used extensively in Michigan. At an MUT intersection, left turns are not allowed at the major intersection.[/code]

Federal Highway Administraion:
http://www.fhwa.dot.gov/publications/re ... ety/09057/
http://www.fhwa.dot.gov/publications/re ... /index.cfm
http://safety.fhwa.dot.gov/intersection ... 0Brief.pdf

Georgia:
http://www.ite.org/Membersonly/annualme ... 2H0303.pdf

Maryland:
http://attap.umd.edu/UAID_ags.php?UAIDType=1&iFeature=8

Missouri:
http://www.hanleyroad.com/where_now/muti.aspx

Canada:
http://www.nrcresearchpress.com/doi/abs ... twoRBAo600\\

Based on the documentation above and from other sites, here how it looks like Michigan Lefts fit into the bigger picture:
2014-04-09_03h20_09.png
(11.37 KiB) Downloaded 1146 times


So even for the article for the Michigan Resource page, I feel we need to indicate this hierarchy.

More research is needed here as this chart is only an example and is hardly comprehensive. I'm out of time tonight, if I am going to ever be ready to fly to Las Vegas very early Friday morning.

Re: [New Page] Median U-turn intersection

PostPosted: Thu May 29, 2014 2:19 am
by GizmoGuy411
Excellent work David.

[New Page] Median U-turn intersection

PostPosted: Wed Mar 19, 2014 7:04 am
by kentsmith9
A rather lengthy discussion has been taking place in the Michigan forums on documenting the "Michigan Left Turn." To be more universal the group has proposed the name be redefined as "Median U-Turn Intersection."

They have been working on a proposal for the wiki here.

I propose that we get some initial feedback on the page as it stands and then create a full page for it with the additional changes we might come up with here.

If someone from the original team wants to lead the general Wiki page creation, that is fine, or I can do it if desired.

Re: [New Page] Median U-turn intersection

PostPosted: Wed Mar 19, 2014 3:08 pm
by kentsmith9
CBenson wrote:I think this would make a good wiki page. Maryland has taken to implementing many Restricted Crossing U-Turn (RCUT) / Super-Street Median Crossover intersections and I do believe that the guidance for the U-turn roads should be similar.

Is there an RCUT page in development by anyone? I did not see "RCUT" in the Main or User namespaces, so I assume not.

CBenson wrote:Currently the U-turn roads are typically not typed as ramps here (because it conflicts with the wiki so they get changed when they are made ramps).

If we need a Ramp there for the right reasons, then we should update the Wiki. Do we need a separate thread just on Where to allow Ramps? I am not familiar with all these other intersection types on the Michigan page. In California we just put up lights and bring everything to its knees. :lol:

Re: [New Page] Median U-turn intersection

PostPosted: Wed Mar 19, 2014 5:55 pm
by kentsmith9
CBenson wrote:These intersections are simply an exception to the guidance not to use ramps for at grade connectors.

I think wherever we say there is an exception, we need to describe why we would do it in one place and not another. For example the [[At-grade connectors]] page says why to use ramps there so people understand the reason. In the U-turn page we just need to do the same thing to explain the "why." Part of the process of teaching people to fish. :D

Re: [New Page] Median U-turn intersection

PostPosted: Thu Mar 20, 2014 3:30 am
by kentsmith9
CBenson wrote:
kentsmith9 wrote:I think wherever we say there is an exception, we need to describe why we would do it in one place and not another. For example the [[At-grade connectors]] page says why to use ramps there so people understand the reason. In the U-turn page we just need to do the same thing to explain the "why." Part of the process of teaching people to fish. :D

Doesn't the U-turn page do that with the following:
Road Type: RAMP
Although this departs from traditional rules for at-grade connectors and for use of the ramp road type, it hides the instructional street name in the client. It is close to the exception stated on the at-grade connector page, however, in that a MUTI is a signed--though unnumbered--exit from the current direction of travel on a roadway.

Otherwise, you get other workarounds like this segment.

I was only speaking generically that we need to explain why we have any exceptions for any rule. That current explanation on the U-turn page seems to be covering most of it. I know we currently only get the Exit instruction for Right turns and we have asked for it to be controllable or also added to Left turns, but that was part of the reason for the exception for At-grade connectors. I don't assume that was the reason for ramps on the U-turn page (which I just now realized). Therefore it seems to cover the exception reason nicely.
sketch wrote:Are you saying this exception should be described and explained briefly (incl. the justification for it) on the at-grade connectors page, but explained in detail on its own page? I'd agree.

Jughandles should be handled similarly, unless it is decided that they don't merit their own page; then we could just redirect "Jughandle(s)" to the AGC page. But this can be discussed with its own thread or in the general AGC page thread that's active right now.

I would agree with all of the above. :D

Re: [New Page] Median U-turn intersection

PostPosted: Thu Mar 20, 2014 9:00 pm
by kentsmith9
sketch wrote:Indeed, although "J-turn" applies only to RCUTs and not MUTIs.

FWIW, Wikipedia uses "Superstreet" for the RCUT page name, and "Michigan left" for the MUTI page name. I really wouldn't mind using both of those here... I had no trouble referring to Michigan lefts as such years before I ever went to Michigan. The abbreviations seem a little hypertechnical.

Normally the Wikipedia pages use the technical name for an item and then on the page they say "also known as" and add the others. All the names can redirect to the page [[Median U-turn intersection]].

I believe we have the following choices:
  • [[Median U-turn intersection (MUTI)]]
  • [[Median U-turn intersection]]
  • [[MUTI]]
  • [[Michigan left]]

I still propose we use [[Median U-turn intersection]] for this page.