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National Boards => General Highway Talk => Topic started by: hbelkins on April 25, 2020, 06:22:11 PM

Title: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: hbelkins on April 25, 2020, 06:22:11 PM
Took a short drive today to see progress on the KY 30 construction in Owsley and Jackson counties, and saw the new J-turn/R-CUT/Michigan Left at KY 80 and KY 1535 west of London. A median U-turn was established on either side of the intersection on the four-lane KY 80 to prohibit straight-through movements on KY 1535, or left turns from 1535 onto 80. This particular intersection provides the traditional left turn from the four-lane in addition to the U-turn movement beyond the intersection.

Is this a new wrinkle? I think it differs from the one that was built at US 68/KY 80 and KY 73 west of Bowling Green, in that all left-turning traffic off the four-lane has to use the U-turn beyond the intersection.
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: Flint1979 on April 25, 2020, 07:05:44 PM
This sounds like the setup on M-84 and Freeland Road between Bay City and Saginaw.
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: sprjus4 on April 25, 2020, 07:25:00 PM
NCDOT usually designs R-CUTS to allow traffic to turn left onto the side roads, and those turning left onto the main highway have to go the opposite direction and turn around.

At one intersection though on the recent US-13 / US-158 widening project, it reverses so traffic turning left onto the side roads have to go down and turn around, and traffic turning left onto the main highway have a dedicated merge lane.

Reversed design at NC-137: https://www.google.com/maps/@36.4339594,-76.8907778,1309m/data=!3m1!1e3!5m1!1e1
Standard configuration: https://www.google.com/maps/@36.4464012,-76.8685105,825m/data=!3m1!1e3!5m1!1e1
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: froggie on April 26, 2020, 09:58:39 AM
Quoteand saw the new J-turn/R-CUT/Michigan Left at KY 80 and KY 1535 west of London.

FTFY.  J-turn/RCUTs are nowhere close to Michigan Lefts for the simple fact that side road traffic cannot continue straight through.

As to the "wrinkle", other states have included left turn lanes right at the side road for years on their J-turns...Minnesota amongst them but there's also at least one example on US 113 in Maryland.

As for US 113 in Maryland, some of the 4-laning south of Berlin over the past decade has included modifications similar to what sprjus mentioned.
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: CoreySamson on April 26, 2020, 01:28:26 PM
Kind of a little off topic, but what exactly is the correct terminology for these turnarounds that were recently built on TX 288?

https://www.google.com/maps/@29.3711262,-95.4269005,3a,75y,174.33h,90t/data=!3m6!1e1!3m4!1s_1oU3uBT8lr4BhwBUjCoJA!2e0!7i16384!8i8192

Satellite imagery hasn't been updated yet.

Brazoria County has been taking out crossings on 288 and has been replacing them with these. Safety, I guess.

I'm just a little confused between the difference between J-turns and Michigan lefts; Texas doesn't really have any other examples I know of.
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: hotdogPi on April 26, 2020, 02:16:04 PM
Quote from: CoreySamson on April 26, 2020, 01:28:26 PM
Kind of a little off topic, but what exactly is the correct terminology for these turnarounds that were recently built on TX 288?

https://www.google.com/maps/@29.3711262,-95.4269005,3a,75y,174.33h,90t/data=!3m6!1e1!3m4!1s_1oU3uBT8lr4BhwBUjCoJA!2e0!7i16384!8i8192

Satellite imagery hasn't been updated yet.

Brazoria County has been taking out crossings on 288 and has been replacing them with these. Safety, I guess.

I'm just a little confused between the difference between J-turns and Michigan lefts; Texas doesn't really have any other examples I know of.

That's a median U-turn.
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: GaryV on April 26, 2020, 03:15:23 PM
If the cross street goes through for traffic that is not turning, that's a Michigan Left.

If the cross street does not go through - all traffic must turn right - that's not a Michigan Left - a J-left?  If all the intersections for a section of the main road are closed for cross traffic, that's a superstreet.
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: sprjus4 on April 26, 2020, 04:27:44 PM
Quote from: GaryV on April 26, 2020, 03:15:23 PM
If the cross street does not go through - all traffic must turn right - that's not a Michigan Left - a J-left?
R-CUT

Restricted Crossing U-Turn
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: US 89 on April 26, 2020, 04:51:12 PM
Utah has installed a design they call a ThrU Turn at a few intersections in the state with high left turn volumes. They aren't exactly your classic Michigan lefts, but they seem similar enough to one that I think they would count as such:

State Street/12300 South, Draper (https://www.google.com/maps/@40.5267587,-111.8900031,658m/data=!3m1!1e3)
Main Street/Hill Field Road, Layton (https://www.google.com/maps/@41.0727056,-111.9797136,326m/data=!3m1!1e3)
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: GaryV on April 26, 2020, 06:36:01 PM
Michigan has a few similar to that where the median is not wide enough, but not as extreme - usually they just make the shoulder a little wider to accommodate the turn.

Such as this one on M-24 north of Pontiac:
https://www.google.com/maps/@42.7205221,-83.242189,312m/data=!3m1!1e3

In some places they will not let semi trucks use the turns where there's not enough of a radius - they have to go to the next or 2nd next crossover.
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: sprjus4 on April 26, 2020, 07:42:17 PM
Quote from: GaryV on April 26, 2020, 06:36:01 PM
Michigan has a few similar to that where the median is not wide enough, but not as extreme - usually they just make the shoulder a little wider to accommodate the turn.

Such as this one on M-24 north of Pontiac:
https://www.google.com/maps/@42.7205221,-83.242189,312m/data=!3m1!1e3

In some places they will not let semi trucks use the turns where there's not enough of a radius - they have to go to the next or 2nd next crossover.
North Carolina does a similar thing, though it's a set standard on every road its implemented on. This example - https://www.google.com/maps/@35.6349293,-77.0639938,3a,75y,182.63h,80.9t/data=!3m6!1e1!3m4!1sRoCY-rdNYcqpOMB73DQVaQ!2e0!7i13312!8i6656 - is the same size median, though a wider radius. Trucks are to be able to use these.

It also provides a storage bay if one cannot safely merge into traffic after U-Turning.
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: CoreySamson on April 27, 2020, 11:14:52 AM
Quote from: 1 on April 26, 2020, 02:16:04 PM
Quote from: CoreySamson on April 26, 2020, 01:28:26 PM
Kind of a little off topic, but what exactly is the correct terminology for these turnarounds that were recently built on TX 288?

https://www.google.com/maps/@29.3711262,-95.4269005,3a,75y,174.33h,90t/data=!3m6!1e1!3m4!1s_1oU3uBT8lr4BhwBUjCoJA!2e0!7i16384!8i8192

Satellite imagery hasn't been updated yet.

Brazoria County has been taking out crossings on 288 and has been replacing them with these. Safety, I guess.

I'm just a little confused between the difference between J-turns and Michigan lefts; Texas doesn't really have any other examples I know of.

That's a median U-turn.
Quote from: GaryV on April 26, 2020, 03:15:23 PM
If the cross street goes through for traffic that is not turning, that's a Michigan Left.

If the cross street does not go through - all traffic must turn right - that's not a Michigan Left - a J-left?  If all the intersections for a section of the main road are closed for cross traffic, that's a superstreet.

Quote from: sprjus4 on April 26, 2020, 04:27:44 PM
Quote from: GaryV on April 26, 2020, 03:15:23 PM
If the cross street does not go through - all traffic must turn right - that's not a Michigan Left - a J-left?
R-CUT

Restricted Crossing U-Turn

Thanks, guys! I was always a little confused about the terminology on these.
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: ErmineNotyours on April 27, 2020, 06:36:52 PM
Quote from: GaryV on April 26, 2020, 06:36:01 PM
Michigan has a few similar to that where the median is not wide enough, but not as extreme - usually they just make the shoulder a little wider to accommodate the turn.

Such as this one on M-24 north of Pontiac:
https://www.google.com/maps/@42.7205221,-83.242189,312m/data=!3m1!1e3

In some places they will not let semi trucks use the turns where there's not enough of a radius - they have to go to the next or 2nd next crossover.

Just a bit north, a turning semi is hanging out into traffic. (https://www.google.com/maps/@42.7214906,-83.243054,69m/data=!3m1!1e3)  Oops!
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: sprjus4 on April 27, 2020, 10:37:15 PM
Quote from: ErmineNotyours on April 27, 2020, 06:36:52 PM
Quote from: GaryV on April 26, 2020, 06:36:01 PM
Michigan has a few similar to that where the median is not wide enough, but not as extreme - usually they just make the shoulder a little wider to accommodate the turn.

Such as this one on M-24 north of Pontiac:
https://www.google.com/maps/@42.7205221,-83.242189,312m/data=!3m1!1e3

In some places they will not let semi trucks use the turns where there's not enough of a radius - they have to go to the next or 2nd next crossover.

Just a bit north, a turning semi is hanging out into traffic. (https://www.google.com/maps/@42.7214906,-83.243054,69m/data=!3m1!1e3)  Oops!
That car probably wasn't too happy.
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: roadfro on May 02, 2020, 04:03:06 PM
Quote from: ErmineNotyours on April 27, 2020, 06:36:52 PM
Quote from: GaryV on April 26, 2020, 06:36:01 PM
Michigan has a few similar to that where the median is not wide enough, but not as extreme - usually they just make the shoulder a little wider to accommodate the turn.

Such as this one on M-24 north of Pontiac:
https://www.google.com/maps/@42.7205221,-83.242189,312m/data=!3m1!1e3

In some places they will not let semi trucks use the turns where there's not enough of a radius - they have to go to the next or 2nd next crossover.

Just a bit north, a turning semi is hanging out into traffic. (https://www.google.com/maps/@42.7214906,-83.243054,69m/data=!3m1!1e3)  Oops!

Flawed design of traffic signal is to blame for that. The u-turn signal heads are placed at the far left of the opposing roadway, so that the first cars in queue have to turn about 90° to see them...so the semi had to start the turn to see the red/green. Would have been better to have these signals placed in/above the median and move the stop bar back so the entire queue can see indications without needing to turn their vehicles.
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: sprjus4 on May 02, 2020, 11:16:51 PM
Quote from: roadfro on May 02, 2020, 04:03:06 PM
Quote from: ErmineNotyours on April 27, 2020, 06:36:52 PM
Quote from: GaryV on April 26, 2020, 06:36:01 PM
Michigan has a few similar to that where the median is not wide enough, but not as extreme - usually they just make the shoulder a little wider to accommodate the turn.

Such as this one on M-24 north of Pontiac:
https://www.google.com/maps/@42.7205221,-83.242189,312m/data=!3m1!1e3

In some places they will not let semi trucks use the turns where there's not enough of a radius - they have to go to the next or 2nd next crossover.

Just a bit north, a turning semi is hanging out into traffic. (https://www.google.com/maps/@42.7214906,-83.243054,69m/data=!3m1!1e3)  Oops!

Flawed design of traffic signal is to blame for that. The u-turn signal heads are placed at the far left of the opposing roadway, so that the first cars in queue have to turn about 90° to see them...so the semi had to start the turn to see the red/green. Would have been better to have these signals placed in/above the median and move the stop bar back so the entire queue can see indications without needing to turn their vehicles.
I'm surprised Michigan hasn't put signals like this at a traditional four-way intersection  :pan:
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: hobsini2 on May 03, 2020, 05:42:52 PM
So if I understand the J-Turn concept that you are describing, Ebenezer Dr at WIS 26 would qualify?

https://www.google.com/maps/@43.1381223,-88.7355004,709m/data=!3m1!1e3?hl=en
Title: Re: Different types of J-turns/R-CUTs/Michigan Lefts?
Post by: JREwing78 on May 05, 2020, 07:44:25 PM
Quote from: hobsini2 on May 03, 2020, 05:42:52 PM
So if I understand the J-Turn concept that you are describing, Ebenezer Dr at WIS 26 would qualify?

https://www.google.com/maps/@43.1381223,-88.7355004,709m/data=!3m1!1e3?hl=en

Yes. There's other examples on Hwy 26 between County N and Fort Atkinson.