SPUI Midpoint Signs

[talllguy]

I'm wondering how other states and jurisdictions are handling the middle area of SPUIs. Maryland SHA is using a diamond shaped ring of yellow flexible delineators and a wood framed sign that I've never really seen anywhere else. This sign is regularly smashed by errant drivers and so it's pretty well beaten up. Shouldn't it be yellow too?

How does your state do this?


SPUI Middle Sign by Elliott Plack, on Flickr

[jeffandnicole]

I wonder if the island is the confusing part.  A left turn at a SPUI should be no more difficult than 2 opposing left turn lanes at a traditional intersection.

[agentsteel53]

I've never seen anything inside a SPUI - but my sample size is limited to California, Arizona, Idaho, and maybe a few other places, mostly out west.

the only time I've ever gotten confused was at night in Boise, and I had been driving for ~20 hours, the last several in horrific snow.  it was I-84 at the airport.  I can't remember what was bad about it, other than the sight lines just weren't quite making perfect sense to me.

[myosh_tino]

The SPUI at CA-87 and Taylor Street has a small island in the middle of the intersection with a set of signs.  Here's that intersection in Google Maps Street View... http://goo.gl/maps/5RsxB

The SPUI at CA-237 and Maude Avenue has nothing inside the SPUI other than some painted lines... http://goo.gl/maps/iMQoa

[hbelkins]

I'm pretty familiar with two of Kentucky's SPUIs -- US 60 over KY 4 in Lexington, and US 60 over KY 676/US 421 in Frankfort.

There's nothing but a painted diamond in the middle of the Lexington SPUI.

There have been a number of different signage attempts for the Frankfort SPUI since I began regularly passing through there about 25 years ago. Current Street View shows no signage, but the history panel that popped up when I looked it up on Street View shows some of the past attempts at signage. Those signs are probably gone because they kept getting knocked down.

Couldn't find a way to create a shortened link to share with the version of Google Maps that popped up when I looked it up.

[jakeroot]

Neither Australia nor the UK use anything in the middle (I don't think you were looking for other countries, but oh well):

[getemngo]

I took a look at a few in Michigan, and there's no pattern whatsoever:

• I-94 & US 24, Taylor: solid white diamond
• US 131 & 44th St, Grand Rapids: white diamond outline
• M-6 & Kalamazoo Ave: raised concrete white diamond outline
• I-94 & Westnedge Ave, Kalamazoo: nothing whatsoever
• Both I-96 SPUIs in Novi: raised concrete and brick diamond (unpainted) with yellow delineators

None of them have any signs, though.

[6a]

The one at I-270 & Sawmill has this thing, I'm amazed people don't plow over it all day.



I honestly don't remember anything on the one at I-71 & SR 665 but it's been awhile since I've been down there.

[realjd]

Are all the MD SPUIs signed with such a ghetto wooden sign? It looks completely unprofessional.

Here in FL we don't usually sign the middle, but elsewhere (can't remember where) I've seen a raised diamond with a keep left sign.

[wisvishr0]

Are all the MD SPUIs signed with such a ghetto wooden sign? It looks completely unprofessional.

This is my first real post here (I've been a long-time lurker), but I've seen that most of you are friendly and don't bite, so I might as well post a reply.

No, not all MD SPUIs are like that. This is the one near my house (at I-270 in MD and Falls Road):

https://www.google.com/maps/@39.07391,-77.164416,3a,75y,199.82h,69.98t/data=!3m4!1e1!3m2!1s5gBditUAaaopdnIN83co4w!2e0

The fact that they're using a wooden sign in that picture probably means it's temporary (or was supposed to be temporary). The setup doesn't seem to confuse drivers here in Rockville MD, without the sign.

[Brian556]

The ones I've seen in Florida only have yellow flexible delineators. Both of the SPUI intersections that I encountered there are under wide overpasses. Due to this fact, it is really hard to see the islands, even with the delineators, because it is just so dark under the bridges. This problem is significant enough that I think it would be a good idea to mark the islands with embedded LED lights.

[briantroutman]

According to a few sources, the interchange between I-180 and US 15 (Market Street) in Williamsport is (or was) the first SPUI in Pennsylvania. If this is any indication, PA won't be using any islands or other "dead zone"  pavement markings at the center.

https://maps.google.com/?ll=41.238663,-76.999032&spn=0.001529,0.002516&t=m&z=19&layer=c&cbll=41.23874,-76.998935&panoid=eNs42CeIx98FvPpWAX4b-A&cbp=12,308.48,,0,0.69

[vdeane]

NYSDOT Region 7 (I-781/US 11): http://goo.gl/maps/205Rj
No barrier, just signs in the road.

NYSDOT Region 1 (I-87/NY 2/NY 7): http://goo.gl/maps/GNG3l
I honestly didn't know the signs were ever there until I checked the street view.  Now there are just cones on the midpoint.  The signs must have gotten run over.

[tdindy88]

Never seen any signs or barriers in the middle of SPUIs in Indianapolis (granted there's only two of them.) Just dashed lines for the turn lanes. In fact, until today I didn't know there were such things as signs or barriers in the middle of the intersection at these interchanges.

[realjd]

Are all the MD SPUIs signed with such a ghetto wooden sign? It looks completely unprofessional.

This is my first real post here (I've been a long-time lurker), but I've seen that most of you are friendly and don't bite, so I might as well post a reply.

No, not all MD SPUIs are like that. This is the one near my house (at I-270 in MD and Falls Road):

https://www.google.com/maps/@39.07391,-77.164416,3a,75y,199.82h,69.98t/data=!3m4!1e1!3m2!1s5gBditUAaaopdnIN83co4w!2e0

The fact that they're using a wooden sign in that picture probably means it's temporary (or was supposed to be temporary). The setup doesn't seem to confuse drivers here in Rockville MD, without the sign.

Welcome! We try to be friendly. Thanks for the pic. I like the gantry those lights are mounted on.

[getemngo]

According to a few sources, the interchange between I-180 and US 15 (Market Street) in Williamsport is (or was) the first SPUI in Pennsylvania. If this is any indication, PA won't be using any islands or other "dead zone"  pavement markings at the center.

Looks like it's not. That SPUI didn't open until October 2007. SPUI's site already listed one at US 22 & PA 66 in December 2004. (The other PA examples on his page are not what we think of as SPUIs - they're mostly left exits whose ramps meet at one intersection.) That one also has nothing to mark its center, so PennDOT's been consistent.

[lordsutch]

Tennessee doesn't put anything in its SPUIs. Usually the most you'll see is striping for multi-lane left turns.

[jakeroot]

NYSDOT Region 7 (I-781/US 11): http://goo.gl/maps/205Rj
No barrier, just signs in the road.

That seems like a terrible idea.

[Scott5114]

Neither of Oklahoma's SPUIs have a center island.

[jeffandnicole]

NYSDOT Region 7 (I-781/US 11): http://goo.gl/maps/205Rj
No barrier, just signs in the road.

That seems like a terrible idea.

And real close to the lane lines.

[jakeroot]

NYSDOT Region 7 (I-781/US 11): http://goo.gl/maps/205Rj
No barrier, just signs in the road.

That seems like a terrible idea.

And real close to the lane lines.

Room for error: zero...point...zero.

[roadfro]

Curiosity gets the better of me, especially to see whether there's a pattern... Here's every SPUI in Nevada and how it is marked in the center of the intersection.

"Under/Over" denotes whether the signal is under the freeway or over the freeway. Constructing agency is also noted.

Northern Nevada:

• I-80 @ Keystone Ave, Reno [NDOT, mid 1990s (?), under] - Raised island, yellow delineators (formerly had 4 symbolic keep left signs, now gone)
  
• I-80 @ Pyramid Way, Sparks [NDOT, 1990s, under] - Raised island, 4 symbolic keep left & yellow object markers on 4 posts
  
• US 395 @ Plumb Lane, Reno [NDOT/Washoe RTC, mid 2000s, under] - Lane lines only (Note: Atypical design with through lanes; former diamond converted to SPUI)
  
• US 395 @ College Pkwy, Carson City [NDOT, 2006, under] - Lane lines only
  
• US 395 @ US 50, Carson City [NDOT, 2006, under] - Lane lines only
  
  Southern Nevada:
  
• I-15 @ St. Rose Pkwy (SR 146), Henderson [NDOT, mid 2000s, over] - Lane lines only
  
• I-15 @ Cheyenne Ave (SR 574), North Las Vegas [NDOT, late 1990s(?), over] - Lane lines only
  
• I-15 @ Lamb Blvd (SR 610), North Las Vegas [NDOT, mid 2000s(?), under] - Lane lines only
  
• US 95 @ Rancho Dr S. (SR 599), Las Vegas [NDOT, 2006, under] - Lane lines only
  
• US 95 @ Rainbow Blvd (SR 595), Las Vegas [NDOT, 2006, over] - Lane lines only
  
• US 95 @ Horse Dr/Fort Apache Dr, Las Vegas [NDOT/City of Las Vegas, early 2010s, over] - Lane lines only
  
• I-215 @ Valley Verde Pkwy, Henderson [Clark Co., late 1990s, over] - Lane lines only
  
• I-215 @ Green Valley Pkwy, Henderson [Clark Co., late 1990s, over] - Lane lines only
  
• I-215 @ Windmill Lane, Henderson [Clark Co., mid 1990s, over] - Lane lines only
  
• CC-215 @ Town Center Dr, Las Vegas [Clark Co., 2005, over] - Lane lines only
  
• CC-215 @ Far Hills Ave, Las Vegas [Clark Co., 2009, over] - Lane lines only
  
• CC-215 @ Lake Mead Blvd, Las Vegas [Clark Co., 2008, over] - Lane lines only
  
  So there's actually far raised islands than I thought in Nevada. Only two, in fact.
  
  The pattern here is that both of these are in the Reno-Sparks area, at SPUIs constructed by NDOT with the traffic lights under the freeway. Interestingly, if I'm not mistaken, these comprise two of the first three SPUIs constructed by NDOT (the third being I-15 @ Cheyenne in North Las Vegas) and among the first (if not the first) SPUIs built in the entire state.

[jakeroot]

British Columbia uses a central island with...what are those signs called? Also, this is only a half spui SPUI. Only exit ramps. Entrance ramps are literally around the corner.

[Zeffy]

British Columbia uses a central island with...what are those signs called?

The technical term for it is an OM-3L, but other than 'hazard stripe marker' I have no idea what you would actually call this.

For NJ, I'm almost certain that there are no SPUIs in the state.

[DaBigE]

British Columbia uses a central island with...what are those signs called?

The technical term for it is an OM-3L, but other than 'hazard stripe marker' I have no idea what you would actually call this.

For NJ, I'm almost certain that there are no SPUIs in the state.

I've also heard them referred to as "tiger boards" or "tiger stripes." Also "clearance stripers."