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Author Topic: Innovative intersection or total cluster F#@$?!!  (Read 1112 times)

tradephoric

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Innovative intersection or total cluster F#@$?!!
« on: April 15, 2019, 11:32:58 AM »

The intersection of Telegraph & Ford Road in metro Detroit is an innovative intersection that includes Thru-turns (Michigan lefts), jughandles, Parallel Flow Intersections/Quadrant intersection, and even has elements of the Florida-T.  Is this the most innovative intersection in the country or a total cluster?  I modeled it in SYNCRHO to give a better visual of how this intersection operates.

https://www.google.com/maps/@42.3269648,-83.2728085,550m/data=!3m1!1e3
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jeffandnicole

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #1 on: April 15, 2019, 12:40:41 PM »

The intersection of Telegraph & Ford Road in metro Detroit is an innovative intersection that includes Thru-turns (Michigan lefts), jughandles, Parallel Flow Intersections/Quadrant intersection, and even has elements of the Florida-T.  Is this the most innovative intersection in the country or a total cluster?  I modeled it in SYNCRHO to give a better visual of how this intersection operates.

https://www.google.com/maps/@42.3269648,-83.2728085,550m/data=!3m1!1e3

The only thing really wrong with it is as drivers approach intersections, they usually want to see consistency.  With an intersection like this, you have traffic going from Right to left using a jughandle, but from left to right using left turn lanes. 

If it flows fine, that's great.  But in cases like this, the breakdown isn't a capacity issue; it's a driver expectation issue.
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jamess

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #2 on: April 15, 2019, 12:48:31 PM »

The only thing really wrong with it is as drivers approach intersections, they usually want to see consistency.  With an intersection like this, you have traffic going from Right to left using a jughandle, but from left to right using left turn lanes. 

If it flows fine, that's great.  But in cases like this, the breakdown isn't a capacity issue; it's a driver expectation issue.

The other thing wrong with it is that it apparently provides zero accommodations for non-motorized users even though you have a relatively dense residential neighborhood a stones throw from a commercial district
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corco

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #3 on: April 15, 2019, 12:51:06 PM »

The only thing really wrong with it is as drivers approach intersections, they usually want to see consistency.  With an intersection like this, you have traffic going from Right to left using a jughandle, but from left to right using left turn lanes. 

If it flows fine, that's great.  But in cases like this, the breakdown isn't a capacity issue; it's a driver expectation issue.

The other thing wrong with it is that it apparently provides zero accommodations for non-motorized users even though you have a relatively dense residential neighborhood a stones throw from a commercial district

It looks like there's a crosswalk on the north and east legs but it's still very ugly. If you live in the southwest quadrant you're screwed.

tradephoric

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #4 on: April 15, 2019, 01:14:54 PM »

The other thing wrong with it is that it apparently provides zero accommodations for non-motorized users even though you have a relatively dense residential neighborhood a stones throw from a commercial district

While i don't agree with this completely, there is a lack of sidewalks along the SW quadrant of the intersection.  However, there are plenty of standard signalized intersections that provide zero accommodations for non-motorized users.  This intersection is capable of providing perfectly acceptable accommodations for non-motorized users while providing potential benefits for motorized users. 
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MNHighwayMan

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #5 on: April 15, 2019, 02:22:29 PM »

This intersection is capable of providing perfectly acceptable accommodations for non-motorized users while providing potential benefits for motorized users. 

But not as it currently exists. If I live in the SW quadrant and want to walk to Del Taco, I have to play Frogger across one of the two roads.
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renegade

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #6 on: April 16, 2019, 06:14:25 PM »

I drive through this intersection on a near-daily basis.  Traffic flows smoothly around the clock, and the area is not that difficult to navigate.  There could be some pedestrian improvements made, but, seriously, dude ... Ford Road is not that hard to cross on foot, and Del Taco is not worth crossing the street for.
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kphoger

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #7 on: April 16, 2019, 07:23:04 PM »

If I live in the SW quadrant and want to walk to Del Taco



Using sidewalks and crosswalks only.  Granted, an unmarked crosswalk across a six-lane arterial with TWLTL (Ford Road) is less than ideal, but perhaps drivers' inability to yield to pedestrians is another matter.
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stridentweasel

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #8 on: April 16, 2019, 09:12:36 PM »

If I live in the SW quadrant and want to walk to Del Taco



Using sidewalks and crosswalks only.  Granted, an unmarked crosswalk across a six-lane arterial with TWLTL (Ford Road) is less than ideal, but perhaps drivers' inability to yield to pedestrians is another matter.

Ugh, I'd prefer to walk on the grass and wait for the green lights on eastbound M-153.  The only unprotected conflict point would be the single lane of traffic exiting from eastbound M-153.

Also, what's up with that little sidewalk to nowhere in the middle of the jughandle?

From a motorist's perspective, the goofiest thing about this whole intersection is that it gives drivers on both directions of US 24 two options for making a left turn onto M-153: the Michigan Lefts and the jughandle or the parallel-flow left turn.  And both of the Michigan Lefts are signalized, so why bother with the redundant left turns at all?  If it were up to me, I would probably eliminate the jughandle and parallel-flow ramps and sell the real estate.  Granted, intersections or interchanges with redundant left turns aren't unheard of in other places, so it's not wrong per se.  It just seems unnecessary.
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kphoger

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #9 on: April 16, 2019, 09:45:26 PM »

Also, what's up with that little sidewalk to nowhere in the middle of the jughandle?

It's not a sidewalk to nowhere.  It's a sidewalk to the bus stop.  https://goo.gl/maps/MB1du5zqNXzvg3yh6
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stridentweasel

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #10 on: April 16, 2019, 10:56:30 PM »

Also, what's up with that little sidewalk to nowhere in the middle of the jughandle?

It's not a sidewalk to nowhere.  It's a sidewalk to the bus stop.  https://goo.gl/maps/MB1du5zqNXzvg3yh6

Oops, I missed that!
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tradephoric

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #11 on: April 17, 2019, 10:27:09 AM »

From a motorist's perspective, the goofiest thing about this whole intersection is that it gives drivers on both directions of US 24 two options for making a left turn onto M-153: the Michigan Lefts and the jughandle or the parallel-flow left turn.  And both of the Michigan Lefts are signalized, so why bother with the redundant left turns at all? If it were up to me, I would probably eliminate the jughandle and parallel-flow ramps and sell the real estate. Granted, intersections or interchanges with redundant left turns aren't unheard of in other places, so it's not wrong per se.  It just seems unnecessary.

MDOT has done this in the past.  They removed the jughandle at Van Dyke & 15 Mile Road and sold off the real estate to be developed.  Now traffic relies solely on the Michigan lefts to complete their turns.


https://www.google.com/maps/@42.55139,-83.02852,651m/data=!3m1!1e3


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tradephoric

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #12 on: April 17, 2019, 01:19:48 PM »

From a motorist's perspective, the goofiest thing about this whole intersection is that it gives drivers on both directions of US 24 two options for making a left turn onto M-153: the Michigan Lefts and the jughandle or the parallel-flow left turn.  And both of the Michigan Lefts are signalized, so why bother with the redundant left turns at all? 

There are definitely times where an extra turning option would be beneficial.  Case in point, Telegraph & Square Lake Road.  The WB Square Lake to SB Telegraph movement is so heavy in the AM rush that turnaround traffic will queue up between the main signal and the turn around.  When Telegraph finally gets a green, the first 30-40 seconds of the phase is dedicated to just clearing out the turnaround traffic that has queued up (making it a slow go for SB Telegraph to clear through the intersection).  When a left turn movement is extremely heavy, it can be useful to have more of a direct turn movement and not rely only on the turnarounds.  Here is Square Lake & Telegraph under the current conditions and a proposed design with a CFI for the WB to SB movement:




https://www.google.com/maps/@42.60292,-83.28988,325m/data=!3m1!1e3

All that said, there are very few Michigan Left intersections that can't cope with the left-turn movements.  It helps that the Median U-turn corridors throughout metro Detroit are mainly 8-lane boulevards which provide a lot of queuing space for the turnaround traffic.  In other parts of the country, where massive 8-lane boulevards are not the norm, it's much more common to have turnarounds along the main boulevard but direct left turns for the side street.  Here are some examples of this:

https://www.google.com/maps/@32.33711,-110.97722,747m/data=!3m1!1e3
https://www.google.com/maps?ll=32.25025,-110.97770&z=17&t=h
https://www.google.com/maps/@33.42005,-86.69436,738m/data=!3m1!1e3
https://www.google.com/maps?ll=38.55088,-90.49369&z=19&t=h
« Last Edit: April 17, 2019, 01:56:21 PM by tradephoric »
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jakeroot

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #13 on: April 17, 2019, 11:19:17 PM »

Michigan Left intersections are annoyingly good at two things: handling pedestrian movements (no left turns to contend with), and being very efficient for vehicles. Unfortunately, the corridors are an issue for pedestrians; all the right-and-u-turn movements mean there are very few signalized intersections for crossing on foot. If we had pedestrian-activated signals at the often-signalized U-turn points, these corridors would become infinitely more user-friendly.

As for the intersection in question...I don't get it. The strangest maneuver seems to be the NB to WB left-then-straight yield. Odd they didn't signalize it (even with an FYA).
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tradephoric

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #14 on: April 18, 2019, 10:50:51 AM »

I actually think this would be a simple redesign for Telegraph & Square Lake that wouldn't require a funky Continuous Flow Intersection.  Just allow direct lefts for WB Square Lake traffic at the existing spur road.  This would greatly simply the heavy WB Square Lake to SB Telegraph turning movement.

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jakeroot

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #15 on: April 18, 2019, 12:06:51 PM »

Must be nice to live in a city where adding direct left turn lanes is the solution. Everywhere else, it's "our direct left turn lanes are too crowded, but there's not enough room for anything else!"

Visibility would be good enough for that left turn from Square Lake, that you may be able to use flashing yellow arrows. Is there anyway to model that? Not even sure if Michigan permits such a setup. The corridor is so well-timed, I'm not sure it's really necessary. But it would be quite helpful during off hours.
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tradephoric

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #16 on: April 18, 2019, 02:07:56 PM »

Visibility would be good enough for that left turn from Square Lake, that you may be able to use flashing yellow arrows. Is there anyway to model that? Not even sure if Michigan permits such a setup. The corridor is so well-timed, I'm not sure it's really necessary. But it would be quite helpful during off hours.

Iím trying to think of a FYA location in this area that crosses 3-lanes of through traffic.  As you can guess, FYA is pretty uncommon at these Michigan style boulevards so the need to have a permissive turn crossing more than 2-lanes of through traffic is uncommon.   In this particular instance, I donít think a FYA would be necessary as having one would just cause WB Square Lake left turning traffic to get to the red light to the south sooner.  Also there is relatively short queueing space along that spur road, so you would like to limit the amount of turners filling the queue space (to prevent traffic from blocking the Square Lake intersection). 

Based on the geometry of the intersection, you would almost just want to give WB Square Lake left turners 30-35 seconds (no more, no less).  If that left turn pocket is getting jammed up, drivers still have the option of utilizing the Michigan left along Telegraph just like they do currently.  But every cycle, you get 20-25 vehicles taking that "direct left" that would otherwise be jamming up in the Michigan Left turn-around and causing backups on SB Telegraph.

 
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renegade

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #17 on: April 18, 2019, 02:21:09 PM »

Now I know you're not from around here ... lights in Michigan are never green long enough for traffic to clear.   :spin:
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sprjus4

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #18 on: April 19, 2019, 06:14:05 PM »

The intersection of Telegraph & Ford Road in metro Detroit is an innovative intersection that includes Thru-turns (Michigan lefts), jughandles, Parallel Flow Intersections/Quadrant intersection, and even has elements of the Florida-T.  Is this the most innovative intersection in the country or a total cluster?  I modeled it in SYNCRHO to give a better visual of how this intersection operates.

https://www.google.com/maps/@42.3269648,-83.2728085,550m/data=!3m1!1e3
Horrible signage from looking at Street View. I'd get lost easily.

Innovative intersections are okay, but now engineers have this huge addiction to them it seems, and it goes too far IMHO.

Just build a compressed urban interchange, SPUI, or diverging diamond and call it a day. Or time the signals better. Or if you're gonna be crazy and build this, at least put a significant amount of overhead signage directing drivers to where they need to go. By this, I mean, 1/2 mile before the intersection, tell drivers going left that they need to turn right then U-Turn in advance, not right at the intersection.
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signalman

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #19 on: April 19, 2019, 09:52:28 PM »

Or if you're gonna be crazy and build this, at least put a significant amount of overhead signage directing drivers to where they need to go. By this, I mean, 1/2 mile before the intersection, tell drivers going left that they need to turn right then U-Turn in advance, not right at the intersection.
That is a Michigan left.  They are very common in MI, and I'm sure that to some degree it's presumed that drivers wishing to go left will be keeping right at the intersection.  Similar instances can be found all over NJ with our infamous jughandles.  There's often no advanced signage that one wishing to turn left must keep right and utilize said jughandle.  There will be an "all turns" or "U and left turns" at reverse jughandles right at the gore.

kphoger

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #20 on: April 22, 2019, 12:53:14 PM »

Just build a compressed urban interchange, SPUI, or diverging diamond and call it a day.

Ummm...  Are you going to give them the extra money for the bridges?
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tradephoric

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #21 on: April 22, 2019, 01:57:03 PM »


https://www.google.com/maps/@42.60292,-83.28988,325m/data=!3m1!1e3

Someone will say just plop a roundabout in.  Of course this has already been tried!  Here's a Michigan Left/Jughandle/roundabout design with a similar "triangular" geometry...


https://www.google.com/maps/@39.6062174,-86.1082077,483m/data=!3m1!1e3
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jakeroot

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #22 on: April 22, 2019, 03:40:56 PM »

Visibility would be good enough for that left turn from Square Lake, that you may be able to use flashing yellow arrows. Is there anyway to model that? Not even sure if Michigan permits such a setup. The corridor is so well-timed, I'm not sure it's really necessary. But it would be quite helpful during off hours.

Iím trying to think of a FYA location in this area that crosses 3-lanes of through traffic.  As you can guess, FYA is pretty uncommon at these Michigan style boulevards so the need to have a permissive turn crossing more than 2-lanes of through traffic is uncommon.   In this particular instance, I donít think a FYA would be necessary as having one would just cause WB Square Lake left turning traffic to get to the red light to the south sooner.  Also there is relatively short queueing space along that spur road, so you would like to limit the amount of turners filling the queue space (to prevent traffic from blocking the Square Lake intersection). 

Based on the geometry of the intersection, you would almost just want to give WB Square Lake left turners 30-35 seconds (no more, no less).  If that left turn pocket is getting jammed up, drivers still have the option of utilizing the Michigan left along Telegraph just like they do currently.  But every cycle, you get 20-25 vehicles taking that "direct left" that would otherwise be jamming up in the Michigan Left turn-around and causing backups on SB Telegraph.

I have seen FYA's in Michigan, but I don't remember any of them being in the Detroit area. Maybe up north somewhere?

A permissive phase for that double left may have an advantage of, especially during off hours, shortening the protected phase, allowing traffic from the north, which has a very short phase, more time to proceed.

Have you factored in the time it would take for a pedestrian to cross Square Lake? Or Telegraph? Incorporating some permissive phases into the intersection could allow all traffic (foot and wheel based) to move simultaneously. If a pedestrian needed to cross Square Lake, which is split-phased in your example, that would seriously dig into available time for other phases (assuming the seven other timed intersections have some play). Perhaps consider running Franklin Road as fully permissive? Or maybe using a lagging protected left when the pedestrian phase is activated?
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tradephoric

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #23 on: April 24, 2019, 01:45:22 PM »

I have seen FYA's in Michigan, but I don't remember any of them being in the Detroit area. Maybe up north somewhere?

I don't think there are too many FYAs in Detroit but there are plenty in the surrounding suburbs

A permissive phase for that double left may have an advantage of, especially during off hours, shortening the protected phase, allowing traffic from the north, which has a very short phase, more time to proceed.

That's a good point i didn't really consider.  Also, there are no left-turn movements along the opposing direction (EB Square Lake) so there wouldn't really be any sight distance issues if you had permissive left-turns along the double left.

Have you factored in the time it would take for a pedestrian to cross Square Lake? Or Telegraph? Incorporating some permissive phases into the intersection could allow all traffic (foot and wheel based) to move simultaneously. If a pedestrian needed to cross Square Lake, which is split-phased in your example, that would seriously dig into available time for other phases (assuming the seven other timed intersections have some play). Perhaps consider running Franklin Road as fully permissive? Or maybe using a lagging protected left when the pedestrian phase is activated?

It's currently tight fitting the pedestrians crossing Square Lake at Franklin. The NB/SB left turns really aren't that heavy where fully permissive phasing could potentially be an option.  One potential problem is that the NB LT would be conflicting with the heavy opposing dual right turn lanes.   I basically modeled the NB/SB movements how they currently operate, but i agree there is room for improvements.  The big thing with the design is redirecting the heavy WB Square Lake to SB Telegraph movement.  This would greatly clear up SB Telegraph especially during the morning rush.
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johndoe

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Re: Innovative intersection or total cluster F#@$?!!
« Reply #24 on: April 24, 2019, 10:01:53 PM »

https://www.google.com/maps/@42.3269648,-83.2728085,550m/data=!3m1!1e3
I guess one con that hasn't been mentioned is the very small storage for the "CFI-left" from northbound to westbound.  The linked image shows how it doesn't take many cars for the queue to spill onto southbound Telegraph. 

I'm surprised two of the movements aren't signalized: the jughandle southbound left and the northbound left crossing southbound Telegraph.  Is that typical for Michigan?  It's funny how organizations don't like FYA across 3 lanes but they allow an unsignalized condition  :confused:

Another con is how the "continuous green" / "Florida T" would make getting to some of those businesses impossible.  Let's say I want some delicious Ihop pancakes...well there's no way I'm getting across all three lanes if there is westbound traffic coming.  One relatively cheap fix for that would be signalizing the southbound jughandle left, and have it always get green at the same time as the "CFI-left".  Now it may be that the signal is setup so that the "CFI-left" only goes when Telegraph gets green at the main intersection, so that wouldn't even be an issue.

Also, this one is annoying me:
https://www.google.com/maps/@32.33711,-110.97722,747m/data=!3m1!1e3
Check out how the dual westbound rights have "no right turn on red" and the right lane immediately merges downstream.  That fourth lane seems pointless to me.

Your Telegraph / Square Lake idea makes sense to me.  However, this is why skewed roads going through a grid causes headaches!  Those signals so close to one another require some tricky timing, and more chances of something not operating as desired (and very small margins of error).
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