There is no reason to fear....SUPER Intersection is here

[Hot Rod Hootenanny]

Couldn't they come up with a better name than 'Super Intersections?' 
http://video.nbc4i.com/v/56555825/super-street-intersection.htm?q=intersection

(In case the link goes away, this concerns an intersection along US 33 between Canal Winchester and Lancaster [SE of Columbus])

[Zmapper]

The link redirected me to MySpace somehow, with no back-button visible (because I opened it in a new tab, but normally if a site redirects a back button is visible). Did anyone else have this problem?

[NE2]

Er? It's a superstreet. Nothing new.

[JREwing78]

Certainly an improvement over what's there now, but a poor fit for a rural highway that's long overdue for a full freeway conversion.

[mgk920]

Isn't that more correctly called a 'Michigan Left™' (or was that a somewhat 'unPC' name for that in central Ohio)?

Mike

[Compulov]

That thing looks like the child of the michigan left and an at-grade SPUI. While I've rarely encountered one, I thought michigan lefts let you still go straight through the intersection.

[mgk920]

That thing looks like the child of the michigan left and an at-grade SPUI. While I've rarely encountered one, I thought michigan lefts let you still go straight through the intersection.

My belief is that they generally do allow for straight-across cross traffic, but IMHO, the hallmarks of the Michigan Left™ are the U-turns that are set back at either end on the main roadway.

Mike

[kphoger]

superstreet.

[Brandon]

It's a modified Michigan Left.  Of course, they'd be mortified in Columbus to actually call it that.

[Anthony_JK]

Looks more like what they call a "3/4th" intersection to me.

Most Michigan Lefts allow for through cross traffic to go straight through. Maybe the ADT values aren't high enough, for if they were, then maybe a CFI or traditional intesection with twin left turn lanes would be better.

Then again, if this roadway is better suited for a freeway upgrade, then maybe a SPUI or DDI??


Anthony

[JREwing78]

I've seen Michigan use Michigan Lefts that didn't allow cross-traffic through (M-59 around Milford is one example). I don't believe I've ever seen them use this particular arrangement, where there's two sets of left turns on each side.

In the video, the ODOT representative admits this was meant to be a cheaper alternative to a full interchange that still improved safety. He estimated $5-$8 million for this v.s. $60 milllion for the interchange. Never mind that one mile away is a full interchange for old US-33, and a full freeway bypass of Lancaster. The road is either controlled-access 4-lane or freeway all the way to I-70 in Columbus.

I could understand the cheap alternative if this road carried 15,000 - 25,000 vehicles per day, but the ODOT representative claims 48,000 vpd. In some places, this stretch would be crying for not only a full freeway conversion but also a widening to 3 lanes each way.

[kphoger]

Again, it's a "Super-Street Median Crossover" intersection, not a "Super Intersection", and it's not exactly new.  The FHWA's informational guide on them is from 2004.  http://www.fhwa.dot.gov/publications/research/safety/04091/10.cfm#c1025

[froggie]

Not a Michigan Left.  Different concept.

NCDOT calls it Superstreet.  MnDOT calls it a "Reduced Conflict Intersection"...basically a 3/4 Intersection with U-turns added on the end....what MnDOT normally terms a 3/4 Intersection doesn't include the U-turns.

[Brandon]

Not a Michigan Left.  Different concept.

NCDOT calls it Superstreet.  MnDOT calls it a "Reduced Conflict Intersection"...basically a 3/4 Intersection with U-turns added on the end....what MnDOT normally terms a 3/4 Intersection doesn't include the U-turns.

Adam, call it what you want, but it is a modified form of Michigan Left.  Take a drive down Eight Mile or Telegraph, and some of the driveways and minor street intersections are set up similarly.

[kphoger]

Adam, call it what you want, but it is a modified form of Michigan Left.

It's not just what he calls it.  It's what it's called.  By the FHWA.
http://www.fhwa.dot.gov/publications/research/safety/04091/10.cfm#c1025

[empirestate]

I assume there would be No Turn on Red from the side street onto the main highway?

And yes, I'm sure this is not a new concept, but then how often do you see news stories like this every time a modern roundabout is proposed somewhere, as if it's the latest new thing? And they still always manage to gather vox pops from people who have no idea how to navigate one...

[hobsini2]

So instead of 1 signal to control traffic, there will be up to 3 signals that someone would have to go through on the lesser street. DUMB!

[froggie]

Nice thing about this configuration is that it reduces the need to meet signal warrants.  All of the examples I'm familiar with (in MD and NC) are unsignalized, though I believe there are a few signalized ones in NC.

Furthermore, the signals can be more easily coordinated, and you're in effect only dealing with 2 signals for the "side street through movement" instead of the 3 feared by hobsini.

[Hot Rod Hootenanny]

According to the report/article, I linked above, Ohio already has one of this style of intersections built in Butler Co (north of Cincy).

[D-Dey65]

Crappy idea, and whether or not it's truly a Michigan Left, it doesn't really look that safe to me at all.


I've seen plenty of instances in Florida where some developer builds a shopping center, and the first thing FDOT does is give them permission to have a channelized left-turn lane, even though it may not be the safest place for it.