Michigan Notes

[JREwing78]

MDOT apparently plans in 2023 to remove the US-12/M-51 bridges and interchange near Niles and replace them with an at-grade intersection with traffic signals and Michigan Left turns.  Some other repaving and reconstruction in the area is planned at the same time.

Considering that US-31 has been gone from the route for over 30 years, traffic on M-51/11th St is certainly not high enough to justify grade-separation. The railroad that was formerly west of the interchange is also gone. It's disappointing to see the grade-separation go away and another stoplight added to US-12, but it's unlikely that traffic would become noticeably worse with the change. It may also improve safety for the existing stoplight at 3rd St, as people would be less likely to confuse US-12 for a freeway.

This also makes clear that the M-60/US-12 interchange east of here is destined to go away in the near future.

[Flint1979]

MDOT apparently plans in 2023 to remove the US-12/M-51 bridges and interchange near Niles and replace them with an at-grade intersection with traffic signals and Michigan Left turns.  Some other repaving and reconstruction in the area is planned at the same time.

Considering that US-31 has been gone from the route for over 30 years, traffic on M-51/11th St is certainly not high enough to justify grade-separation. The railroad that was formerly west of the interchange is also gone. It's disappointing to see the grade-separation go away and another stoplight added to US-12, but it's unlikely that traffic would become noticeably worse with the change. It may also improve safety for the existing stoplight at 3rd St, as people would be less likely to confuse US-12 for a freeway.

This also makes clear that the M-60/US-12 interchange east of here is destined to go away in the near future.

I was thinking that they'd keep the M-60/US-12 interchange the same. It makes more sense to remove the one at M-51/US-12 since that is kind of a tight setup there anyway and there are residential areas right next to it. Besides the bridge that US-12 uses to cross over M-51 is old and probably needing replacement anyway by now. The guardrails tells it's age.

[JREwing78]

I was thinking that they'd keep the M-60/US-12 interchange the same. It makes more sense to remove the one at M-51/US-12 since that is kind of a tight setup there anyway and there are residential areas right next to it. Besides the bridge that US-12 uses to cross over M-51 is old and probably needing replacement anyway by now. The guardrails tells it's age.

US-12 @ M-51 is by far the more heavily-trafficked interchange, with a total of about 35,000 vpd using it v.s. about 24,000 vpd for M-60/US-12. It's also not significantly older (built in 1956 v.s. 1960 for US-12/M-60). If traffic didn't justify rebuilding the US-12/M-51 interchange, it certainly doesn't for US-12/M-60.

[Stephane Dumas]

Someone posted on another forum some drawings of the DDI interchanges who'll replace the current interchanges on I-75 at 14 Mile Road and Big Beaver(16 Mile) Road.
https://www.detroityes.com/mb/showthread.php?23875-I-75-Mega-Project-to-Include-Diverging-Diamond-Interchanges-at-14-Mile-Big-Beaver

[wanderer2575]

Someone posted on another forum some drawings of the DDI interchanges who'll replace the current interchanges on I-75 at 14 Mile Road and Big Beaver(16 Mile) Road.
https://www.detroityes.com/mb/showthread.php?23875-I-75-Mega-Project-to-Include-Diverging-Diamond-Interchanges-at-14-Mile-Big-Beaver

Wow!  I did not know the I-75 reconstruction project included removing the existing interchanges and replacing them with DDIs; this is the first I've read of it.  I don't even see it mentioned in any project summary descriptions on the MDOT website.

I wonder how much these DDIs will really improve traffic flow, given that both 14 Mile and Big Beaver have a mess of other traffic signals very close to their I-75 interchanges.

[Flint1979]

Having a left lane off ramp isn't the worst of things. However the interchange at Square Lake is much improved now. A left lane on ramp is dangerous and you encounter that at exit 93 Dixie Hwy as well in both directions. I can't wait to see how they plan on getting all this done by 2020.

[tradephoric]

Wow!  I did not know the I-75 reconstruction project included removing the existing interchanges and replacing them with DDIs; this is the first I've read of it.  I don't even see it mentioned in any project summary descriptions on the MDOT website.

Here's the design MDOT chose for the I-75/Big Beaver interchange:


Here's the design i wish they had selected.  Don't diverge Big Beaver through traffic if they aren't entering onto the freeway.  This design would require roughly the same bridge deck length as the proposed design but the I-75 bridge deck width would need to be wider to accommodate the deceleration lanes for the exiting loop ramps.  But for 12 foot wider bridge decks, you would achieve much better coordination/lower delays along Big Beaver Road.  And there's enough ROW for this design (considering the current interchange is a full cloverleaf).

https://www.youtube.com/watch?v=Y_dKx6c_gNI

Here's the current signal progression you can achieve along Big Beaver.  Drivers cruise for multiple miles in either direction along Big Beaver without hitting a red light.  The Diverging Diamond is going to ruin good signal progression along Big Beaver between Crooks and Livernois and jam up traffic with the closely spaced traffic signals just east and west of the interchange.  MDOT is getting DDI happy just like the rest of the states.  Flavor of the month interchange 10 years ago was the SPUI... today it's the DDI.   

https://www.youtube.com/watch?v=eB2H4bGp4Jc
https://www.youtube.com/watch?v=o2BOYF0JQFE

[renegade]

Here's the design MDOT chose for the I-75/Big Beaver interchange:


Here's the design i wish they had selected.  Don't diverge Big Beaver through traffic if they aren't entering onto the freeway.  This design would require roughly the same bridge deck length as the proposed design but the I-75 bridge deck width would need to be wider to accommodate the deceleration lanes for the exiting loop ramps.  But for 12 foot wider bridge decks, you would achieve much better coordination/lower delays along Big Beaver Road.  And there's enough ROW for this design (considering the current interchange is a full cloverleaf).

https://www.youtube.com/watch?v=Y_dKx6c_gNI

Here's the current signal progression you can achieve along Big Beaver.  Drivers cruise for multiple miles in either direction along Big Beaver without hitting a red light.  The Diverging Diamond is going to ruin good signal progression along Big Beaver between Crooks and Livernois and jam up traffic with the closely spaced traffic signals just east and west of the interchange.  MDOT is getting DDI happy just like the rest of the states.  Flavor of the month interchange 10 years ago was the SPUI... today it's the DDI.   

https://www.youtube.com/watch?v=eB2H4bGp4Jc
https://www.youtube.com/watch?v=o2BOYF0JQFE

Your design takes up more land area than the current layout does.

[Flint1979]

That interchange has always sucked because it's on a curve on I-75

[tradephoric]

Here's another massive Diverging Diamond that was built in Florida.  It takes the guy 3 minutes to drive about 1/2 mile (that's with the guy pausing the video twice while stuck at red lights).  While there is a lane of traffic closed off at the beginning of the video, by the time the driver reaches the DDI traffic signals it appears all lanes of traffic are open. 

https://www.youtube.com/watch?v=WFXaArpY3hM

Your design takes up more land area than the current layout does.

Your claim is invalid considering my design is nothing more than a conceptual SYNCHRO model.  It's essentially a partial cloverleaf while the existing layout is a full cloverleaf.  In general, a partial cloverleaf is capable of taking up less ROW than a full cloverleaf.  It's true that the width of Big Beaver would be wider with my design compared to the current configuration, but it would be a similar width to the DDI that is being proposed (and a wide arterial under the bridge deck doesn't take up any more ROW than the current configuration, seeing that the existing loop ramps are already taking up that ROW to begin with).

[wanderer2575]

Here's the design MDOT chose for the I-75/Big Beaver interchange:


Here's the design i wish they had selected.  Don't diverge Big Beaver through traffic if they aren't entering onto the freeway.  This design would require roughly the same bridge deck length as the proposed design but the I-75 bridge deck width would need to be wider to accommodate the deceleration lanes for the exiting loop ramps.  But for 12 foot wider bridge decks, you would achieve much better coordination/lower delays along Big Beaver Road.  And there's enough ROW for this design (considering the current interchange is a full cloverleaf).

https://www.youtube.com/watch?v=Y_dKx6c_gNI

The current cloverleaf interchange has two signals in each direction on Big Beaver Road.  The DDI will have two signals in each direction.  Your design would have two signals in each direction, would require more space than the DDI in the northeast and southwest quadrants (MDOT might want to sell current ROW that would become excess with the DDI), and probably would require additional (unavailable) ROW east and west of the interchange to move the carriageways apart for the necessary widened median.  I'm not sure I'm sold on the DDI over the current configuration, but I don't see where your design is an improvement.

That interchange has always sucked because it's on a curve on I-75

I remember when the I-75 bridges were widened to construct the C/D carriageways -- now those carriageways are being removed.

[tradephoric]

The current cloverleaf interchange has two signals in each direction on Big Beaver Road.  The DDI will have two signals in each direction.  Your design would have two signals in each direction, would require more space than the DDI in the northeast and southwest quadrants (MDOT might want to sell current ROW that would become excess with the DDI), and probably would require additional (unavailable) ROW east and west of the interchange to move the carriageways apart for the necessary widened median.  I'm not sure I'm sold on the DDI over the current configuration, but I don't see where your design is an improvement.

A few points:
1.  My design would have traffic signals that only stop one direction of travel along Big Beaver while the DDI would have traffic signals that stop both directions.  Much easier to coordinate traffic signals that only stop one direction of travel.  Good signal progression along a major 6-lane boulevard (ie. my design) equates to lower stops and delays for drivers.  Poor signal progression along a major 6-lane boulevard (ie. DDI design) equates to increased stops and delays for drivers. 

2.  If you look at the proposed DDI design you really aren't gaining much ROW in the SW quadrant.  I'd be surprised if MDOT is selling any ROW on the SW quadrant.  So compared to my design, the DDI would really only be gaining ROW on the NE quadrant.  The greater Toronto area has a population of nearly 6 million people, yet nearly every interchange in the city is a parclo.  If a major metropolis of 6 million people can manage with Parclo designs that take up a little bit more ROW, i'm pretty sure a Parclo on Big Beaver in Troy, Michigan would be adequate.

[tradephoric]

...and probably would require additional (unavailable) ROW east and west of the interchange to move the carriageways apart for the necessary widened median.

I disagree that my design would require additional ROW along Big Beaver east and west of the interchange.  Here's a more accurate interpretation of the design.  Instead of diverging all traffic  (like the DDI) just diverge the traffic that is actually going to be entering the freeway.  Makes too much sense maybe.

Your design takes up more land area than the current layout does.

I also disagree with you.  My design would take up less land area than the current interchange configuration.

https://www.youtube.com/watch?v=0v1QPaYISFA

Here's a rendering of how the contraflow lefts might look from ground level.  Not exactly the same interchange design but you get the idea.

[Flint1979]

The closure of I-475 in Flint has begun. As far as I know it's closed from the northern terminus to it looks like at least the Carpenter Road exit. This closure at least for now looks like it only consists of the SB lanes.

[Flint1979]

...and probably would require additional (unavailable) ROW east and west of the interchange to move the carriageways apart for the necessary widened median.

I disagree that my design would require additional ROW along Big Beaver east and west of the interchange.  Here's a more accurate interpretation of the design.  Instead of diverging all traffic  (like the DDI) just diverge the traffic that is actually going to be entering the freeway.  Makes too much sense maybe.

Your design takes up more land area than the current layout does.

I also disagree with you.  My design would take up less land area than the current interchange configuration.

https://www.youtube.com/watch?v=0v1QPaYISFA

Here's a rendering of how the contraflow lefts might look from ground level.  Not exactly the same interchange design but you get the idea.

Wouldn't that be somewhat similar to the M-59 and US-23 interchange?

[tradephoric]

^You can kind of look at contraflow left turns at an interchange as a spread out SPUI, but really i feel the interchanges are quite different.   If you want to see a combination between a Parclo and a SPUI, take a look at a design like this:

https://www.youtube.com/watch?v=6vef4O6Vs_A

[tradephoric]

When i drive 8 Mile Road i can usually cruise from Grand River to Woodward without getting stopped at a red light.  Then like clockwork i get stopped at John R just east of Woodward.  Here's a video of my typical drive down 8 Mile:

https://www.youtube.com/watch?v=oea5WLUmGjs

This is a time-distance diagram of how 8 Mile is timed from Livernois to Dequindre.  The corridor is capable of great dual progression along this stretch but MDOT has it messed up.  You get stopped in both directions of travel when you drive this stretch of 8 Mile.   The coordination of 8 Mile has been the same for years, and it's really unnecessary for drivers to consistently get stopped at John R and Dequindre.

[kphoger]

 

8 Mile Road

[Flint1979]

I cruised on 8 Mile the other day. I got on it just east of Van Dyke (where Conner ends at Bramford) and stayed on it until I-75 (about 4 miles). I was able to hit every light as a green light and made it to I-75 in just over 4 minutes.

[Flint1979]

US-23 and M-59 is setup like that. It's more of a rural area but the interchange handles quite a bit of traffic.

[tradephoric]

I cruised on 8 Mile the other day. I got on it just east of Van Dyke (where Conner ends at Bramford) and stayed on it until I-75 (about 4 miles). I was able to hit every light as a green light and made it to I-75 in just over 4 minutes.

That's a good run!  But I bet if you had traveled a little farther west you would have gotten slowed down at John R.  That's the light that always seems a little screwy.  I'd understand if you get good signal progression in one direction (at the expense of the other direction), but it seems no matter what direction you are traveling down 8 Mile there's a good chance you get stuck at John R.

[MNHighwayMan]

Someone should erect and maintain a high scoreboard.

[Flint1979]

A part of old US-10 in Midland was permanently closed last year. Dow has property on both sides of Saginaw Road and they have combined there plant and successfully got approval from the Midland City Council to close the stretch for good and combine there plant into one property. Saginaw Road is now closed between Salzburg Road and Mark Putnam Road. Therefore you are no longer able to clinch old US-10.

[tradephoric]

Anyone who has driven Telegraph & Square Lake during rush hour knows how backed up the intersection can get.  The heavy WB Square Lake traffic who uses the Michigan Left turnaround on Telegraph to continue SB jams up between the main signal and the turnaround, especially in the morning.  Here is a design that would allow direct lefts for WB Square Lake traffic that wish to continue SB on Telegraph.

https://youtu.be/cAGfr8dqCHU


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

[tradephoric]

OK this is the last model i'll post of this, but I think this could work awesome if MDOT ever reconfigured this intersection like this. 

https://youtu.be/wUrD4S2u8rQ