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National Boards => General Highway Talk => Topic started by: J N Winkler on November 06, 2009, 07:46:50 AM

Title: Order of signed destinations reached from a common ramp
Post by: J N Winkler on November 06, 2009, 07:46:50 AM
I'm opening this thread to ask about state and local standards for the order in which destinations are listed on an advance guide or exit direction sign when those destinations are reached by a common exit ramp off the freeway (not counting slip lanes to collector-distributor roadways).  The MUTCD is silent on this issue, so states and localities have considerable latitude to have their own standards, or none at all.

In Missouri, for example, MoDOT's mantra is "ahead, left, right," as on D-series conventional-road direction signs.  This means that if you exit at a diamond interchange, the destination on left will be listed before the destination on right.  If "Poplar Bluff" is on the left and "Sikeston" is on the right, then the sign will say "Poplar Bluff"/"Sikeston."  But if you exit at the same diamond interchange from the other direction, the order of listing will be reversed--"Sikeston"/"Poplar Bluff"--because "Poplar Bluff" is on the right while "Sikeston" is on the left.  It is also my understanding that MoDOT applies the same rule to shields shown on signs, regardless of road class, which creates the theoretical possibility that a US or state route shield could appear to the left of an Interstate shield on a sign.

Minnesota follows a similar rule but does not extend it to the shields.  (My test cases are Exit 12 on I-90, for Rock Rapids and Luverne, and the Business I-35/TH 21 exit for Faribault and Le Center off I-35.)  The same observation seems to hold for Arizona (test cases:  Colossal Cave Rd./Wentworth Rd. and Mescal Rd./J Six Ranch Rd. off I-10 east of Tucson).

In California, on the other hand, there appears to be no such ordering rule.  (My test case is Exit 109 on I-15 in District 8--"Los Angeles"/"San Bernardino" in both directions, according to the signing plans.)  I haven't done a full check of TxDOT districts, but TxDOT seems to be the same, at least in the Yoakum District.  So does Kansas (test cases:  K-23 Grainfield/Gove; Business US 40/US 283 WaKeeney/Hill City).

What about other states?
Title: Re: Order of signed destinations reached from a common ramp
Post by: Bryant5493 on November 06, 2009, 08:29:34 AM
On I-85 southbound, right at the Fulton-Coweta line, exit 56 - Collinsworth Road has the destination of "Palmetto," for southbound travelers; northbound travelers are greeted by "Exit 56 - Collinsworth Road/Palmetto/Tyrone."

Also, at exit 47 on I-85 southbound, southbound drivers are greeted by BGSs that read, "Exit 47 - S.R. 34/Bullsboro Drive/Newnan/Shenandoah"; northbounders see signage that reads, "Exit 47 - Bullsboro Dr./Newnan/Peachtree City."


Be well,

Bryant
Title: Re: Order of signed destinations reached from a common ramp
Post by: Michael on November 06, 2009, 11:33:40 AM
All of what I've seen in New York is the closest destination listed first.  If a city has multiple exits, the city isn't indicated in exits past the downtown area.

For example, NY Thruway Exit 37 has Liverpool as a destination for westbound traffic, but Syracuse for eastbound traffic.  Syracuse is used because the exit is east of Liverpool.  Exit 38 (further to the west) has Liverpool as a destination in both directions because the exit is due north of Liverpool.

Another example is signage for the State Fairgrounds on the Thruway.  Eastbound traffic is instructed to exit at I-481 (Exit 34A) to get to I-690 to the Fairgrounds.  Eastbound traffic is directed to exit on to I-690 (Exit 39).  The Fairgrounds are about four miles southeast of Exit 39.

This method is used to prevent backtracking on surface streets.
Title: Re: Order of signed destinations reached from a common ramp
Post by: Scott5114 on November 06, 2009, 11:56:11 AM
Oklahoma has no pattern that I really know about other than maybe the nearest town first. (These examples are all from I-35.) Exit 104 makes enough sense...Goldsby, then Washington, as Goldsby is right off the exit and Washington is down the road a ways. The OK-33 exit list Guthrie, then Perkins and Cushing. Exit 174 is about equidistant between Hennessey and Stillwater, but Stillwater is the larger, well known town (and probably destination for most people exiting there, as it is home to Oklahoma State University), so Stillwater is listed first.
Title: Re: Order of signed destinations reached from a common ramp
Post by: Revive 755 on November 06, 2009, 01:14:01 PM
Quote from: J N Winkler on November 06, 2009, 07:46:50 AM
In Missouri, for example, MoDOT's mantra is "ahead, left, right," as on D-series conventional-road direction signs.  This means that if you exit at a diamond interchange, the destination on left will be listed before the destination on right.  If "Poplar Bluff" is on the left and "Sikeston" is on the right, then the sign will say "Poplar Bluff"/"Sikeston."  But if you exit at the same diamond interchange from the other direction, the order of listing will be reversed--"Sikeston"/"Poplar Bluff"--because "Poplar Bluff" is on the right while "Sikeston" is on the left.  It is also my understanding that MoDOT applies the same rule to shields shown on signs, regardless of road class, which creates the theoretical possibility that a US or state route shield could appear to the left of an Interstate shield on a sign.

Seems to be a decent number of flukes where MoDOT has used the same ordering of cites for both sides of the highway.
Title: Re: Order of signed destinations reached from a common ramp
Post by: florida on November 06, 2009, 01:48:27 PM
FDOT does the closest-city-top-furthest-city-bottom with BGSs. Pretty sure if two designation on LGSs, pointing the same direction, are done the same way as it makes more sense.

I-95 at Exit 298 only lists one city in each direction (NB gets St. Augustine and SB gets Bunnell) as they're more "accessible" from their respective directions you come off of I-95, but both are signed on the directionals on the exit ramp.

I-10 and FL 59 is one of only three exits here to not have any city or point of interest listed. The tiny area of Lloyd is too small, and I guess they don't consider Wacissa (even home to Wacissa Springs) equally as important.


Edited to fix misinformation as pointed out by jdb1234 because I forgot about those two.
Title: Re: Order of signed destinations reached from a common ramp
Post by: jdb1234 on November 06, 2009, 09:33:11 PM
^^  Unless it has changed, the interchange between I-10 and CR 257 2 exits from FL 59 does not have any city or point of interest listed.  Also I-75 @ FL 326 near Ocala does not list any destinations.

I believe Alabama list destinations closest first but this is not always the case. 

I-65 @ Escambia CR 1, US 78 @ Marion CR 45 and US 78 Eastbound @ AL 118 does not have any cities or points of interest listed.

US 78 Exit 54 does not list anything at all! Only a gore point sign exists at this interchange.
Title: Re: Order of signed destinations reached from a common ramp
Post by: roadfro on November 06, 2009, 11:48:50 PM
MUTCD Section 2D.27 ("Route Sign Assemblies") indicates that information on conventional roads (guide signs and/or route shield assemblies) should be ordered such that routes intersecting from the left should have information displayed on the left or top of the sign, routes coming from the right should be on the bottom/right of the sign, and through-route information should be in the middle.  So Missouri's "ahead, left, right" mantra isn't compliant...although I would suspect there are many signs in many states that don't follow this practice perfectly.

Of course, what's stated above applies to conventional signs, and not the BGSs used on freeways.  Nothing I can find in the MUTCD, SHS, or elsewhere makes any mention of which destination would come first on an Advance Guide or Exit Direction sign.  All that is mentioned is that the states select destinations, and that control cities for Interstates are listed in an AASHTO publication.  I seem to recall reading something that said if the two destinations are in opposite directions, the southbound or eastbound destination should come first--unfortunately, I can't recall where I read that or what kind of document it was in.


In Nevada, if two destinations are on the same exit sign, in most instances the two cities/towns/locales are in the same direction. In such cases, the nearer location is usually listed first. If the two destination cities are in opposite directions, the closer city--which usually happens to also be the more "major" city or greater traffic generator--is usually listed on the top line (i.e. most signs on US 395 at the I-80 interchange which use the legend "Sacramento/Elko"). In the rarer case where the two destination cities are shown side by side, the cities are usually listed according to the relative direction a driver will turn after seeing the sign (i.e. I-80 EB approaching US 395 has "Susanville  Carson City", where going north to Susanville would mean veering left).

The situation is slightly different in the case of street names.  If the road or highway changes names at (or near) the interchange, the larger traffic generator or more major street usually comes first.  If the two cross streets listed on the sign are parallel or offset, such that a ramp involves a frontage or collector road, the first street encountered is generally listed on the top line.
Title: Re: Order of signed destinations reached from a common ramp
Post by: J N Winkler on November 07, 2009, 06:33:09 AM
Actually, ยง 2D.27 strictly speaking refers just to shields and tabs, not the D-series guide signs, and information pertaining to left-hand routes is to be at the top or center of vertical arrangements, with straight-ahead routes being always at the top in vertical arrangements.  (The provision for left-hand routes to be at the top of vertical arrangements is designed to cater for assemblies where no straight-ahead route is signed.)  It is in horizontal arrangements that the straight-ahead routes are in the middle.

The figures for D3-1 signs in Standard Highway Signs follow the same "ahead, left, right" ordering rule as that prescribed for vertical arrangements of route shields.

Regarding Kansas, I think the norm is to place the nearer destination first on advance guide signs.  The two test cases both follow this rule (Grainfield is closer to I-70 than Gove, so is listed first both eastbound and westbound; WaKeeney is closer than Hill City, so it is also listed first in both directions; WaKeeney and Hill City are both on the same side of I-70 while Grainfield and Gove are on opposite sides).

For clarity I should note that my information regarding MoDOT's "ahead, left, right" mantra does not come from any official MoDOT guidance that I have seen, including the MoDOT design standards wiki ("Engineering Policy Guide") or the two or three editions of the MoDOT Signing Manual I have seen (it is a mess).  The rule was spelled out by a MoDOT traffic engineer at a statewide Sign Meeting MoDOT held in 2008.  It seems that MoDOT's district traffic personnel and consultants are expected to follow it despite its being effectively undocumented.  This is not as bad as it sounds since it appears that project engineers have been expected since at least 2003 to send sign sketches to Jefferson City so Traffic Division at MoDOT HQ can prepare the actual sign designs in SignCAD.  This is meant to assure uniformity in design but it is perhaps not surprising that many signs still exist with no particular ordering of destinations.
Title: Re: Order of signed destinations reached from a common ramp
Post by: burgess87 on November 07, 2009, 09:14:06 AM
TxDOT has several of these sign layout guidelines in their Standard Highway Signs publication:

ftp://ftp.dot.state.tx.us/pub/txdot-info/library/pubs/gov/sign/3_guide.pdf  Pages 45-53
Title: Re: Order of signed destinations reached from a common ramp
Post by: Alps on November 07, 2009, 10:36:47 AM
The Port Authority of NY/NJ has cited the MUTCD in developing a policy of ahead-left-right for arrow priority on signs.
Title: Re: Order of signed destinations reached from a common ramp
Post by: akotchi on November 07, 2009, 11:49:44 AM
If you look at Figure 2E-27 of the MUTCD (freeway to freeway interchange), the "east-west" approach shows a common ramp breaking into two ramps after it leaves the highway.  The destinations on the "common" guide sign are listed based with the left fork first, then the right fork.

Looking at Figure 2E-31, for a lesser interchange, the destinations are ordered based on left turns then right turns off of the ramp, no matter if the ramp is a finger ramp or a loop ramp.

In my experiences with guide signing design, some agencies preach the MUTCD figures as gospel as much as the text.

I am sure there are many cases where this convention is not used, especially if the interchange was reconfigured at one time.  (Why change the advance guide signs to switch the destinations?)
Title: Re: Order of signed destinations reached from a common ramp
Post by: roadfro on November 07, 2009, 07:57:12 PM
Well never mind what I said earlier.  Guidance in Section 2D.34 suggests using the "ahead, left, right" scheme for D-series guide signs, while a standard states that nearer locations in the same direction must be listed first.

Also, I realized that the Nevada DOT method I mentioned for signing opposite-direction control cities on a single ramp is also not universal.  Sometimes the nearer location is used, while other times it is based on direction (or direction at the ramp).  The signing I mentioned on US 395 approaching I-80 is interesting because on further review, the exit direction signs at the interchange and nearest advance guide sign are direction based, but the first/furthest advance guide sign has the two cities reversed (this strangely occurs in both directions).  Since there are so few of these kinds of exit in Nevada, it's not surprising that it's inconsistent.  To my knowledge, NDOT doesn't have a guide sign design guide--if they do, it's not published publicly.