News:

Thanks to everyone for the feedback on what errors you encountered from the forum database changes made in Fall 2023. Let us know if you discover anymore.

Main Menu

Arrow-Per-Lane (APL) signs

Started by cl94, January 12, 2015, 10:39:41 PM

Previous topic - Next topic

cl94

I can't find a topic on these things that are rapidly appearing, so I figured I'd start one. Yesterday, I was at a workshop on the rebuilding of the I-35/I-435/US 69/K-10 interchange complex outside of Kansas City. In a breakout group, I, along with a few engineers from the FHWA and private firms, analyzed the signage plan provided by KDOT. While the complex was designed long before the introduction of APLs, someone decided to redesign all of the signage so any assembly with option lane signage features an APL covering all lanes. I'll post a couple low-quality cell phone pics of the signage map below. I-35 runs NNE-SSW and K-10 is unlabeled.





A few things I'd like to point out:

-On I-435 north of K-10, NB has an APL sign with the portion over the left lane being a yellow "lane ends" sign and a black up arrow
-At the same location SB, a one-lane exit without an option lane is on the APL sign.
-In several locations, most notably on I-435 EB just east of I-35, the APL has two exits, each with an option lane, departing quickly from the right. Arrow directions are "up", "slight right", and "right".

Each of us in the group agreed that the MUTCD provides limited guidance as to how APLs are to be applied, lacking examples of how to sign such a complex interchange that would have had simpler signage if diagrammatic signs weren't discouraged. Ohio's solution with the slanted arrows isn't great, but the system here is overly complex due to MUTCD requirements regarding option lanes and APLs.

Any thoughts or other APL talk you'd like to bring up?

Please note: All posts represent my personal opinions and do not represent those of my employer or any of its partner agencies.

Travel Mapping (updated weekly)


Pete from Boston

I find the thin dividing line that depends from the top edge of the signs to be, well, a little half-assed.

jakeroot

#2
British Columbia did this along Highway 1 with the $3B gateway program. Only difference is that they use APLs regardless of the number of lanes exiting nor whether or not they are exit-only. Most interchanges have APLs now. Here's a photo that demonstrates what most junctions are signed like (ignore the unfinished bottom bit):



EDIT: Here's another sort-of-APL setup, to give you an idea of how liberally BC uses up arrows:


Ned Weasel

The current MUTCD attempts to stamp out the wide variation in different DOTs' usage of down arrows.  The next MUTCD will attempt to stamp out the wide variation in different DOTs' usage of APL.
"I was raised by a cup of coffee." - Strong Bad imitating Homsar

Disclaimer: Views I express are my own and don't reflect any employer or associated entity.

Zeffy

The problem with APLs is that they are way too fucking big. Having a huge sign that spans 4-6 lanes of traffic just isn't cost-practical IMO. I think diagrammatic signs, or heck even the old dancing arrows approaches were more better in that regard. However, Minnesota's way of putting an arrow with a vertical line above it also seems to communicate its point decently well, so I think maybe more studies should be done on that as well.
Life would be boring if we didn't take an offramp every once in a while

A weird combination of a weather geek, roadgeek, car enthusiast and furry mixed with many anxiety related disorders

machias

Quote from: cl94 on January 12, 2015, 10:39:41 PM
I can't find a topic on these things that are rapidly appearing, so I figured I'd start one. Yesterday, I was at a workshop on the rebuilding of the I-35/I-435/US 69/K-10 interchange complex outside of Kansas City. In a breakout group, I, along with a few engineers from the FHWA and private firms, analyzed the signage plan provided by KDOT. While the complex was designed long before the introduction of APLs, someone decided to redesign all of the signage so any assembly with option lane signage features an APL covering all lanes. I'll post a couple low-quality cell phone pics of the signage map below. I-35 runs NNE-SSW and K-10 is unlabeled.





A few things I'd like to point out:

-On I-435 north of K-10, NB has an APL sign with the portion over the left lane being a yellow "lane ends" sign and a black up arrow
-At the same location SB, a one-lane exit without an option lane is on the APL sign.
-In several locations, most notably on I-435 EB just east of I-35, the APL has two exits, each with an option lane, departing quickly from the right. Arrow directions are "up", "slight right", and "right".

Each of us in the group agreed that the MUTCD provides limited guidance as to how APLs are to be applied, lacking examples of how to sign such a complex interchange that would have had simpler signage if diagrammatic signs weren't discouraged. Ohio's solution with the slanted arrows isn't great, but the system here is overly complex due to MUTCD requirements regarding option lanes and APLs.

Any thoughts or other APL talk you'd like to bring up?



Looking at many of these APL signs in the photos, especially the ones spanning five or six lanes, I see a lot of wasted space which equals a lot of wasted money. Even down or dancing arrows per lane would reduce the cost quite a bit. I agree with Zeffy, the APL signs are just way too big!

jakeroot

If the MUTCD allowed modifiable arrows (so they didn't have to be 4 feet tall) we could make pretty short APL signs that were still decently effective and didn't waste so much space.

Are dancing arrows still allowed?

cl94

The sheer cost of each APL was mentioned. Another suggestion I heard was to adopt Ontario's option lane signage, which I agree with. If you're not familiar with Ontario's practice, they place a yellow sign at the side of the road illustrating the movements of each lane. The arrows look like APL arrows, but lanes that either do not exit or are not option lanes are not shown.

The biggest problem with the dancing arrows is that they aren't universal and induce confusion. I remember my parents being very confused when we moved to Ohio and saw them because option lanes out here, if signed at all, had normal down arrows or diagrammatics until APLs cane around. Downward-slanting arrows out here indicated when a freeway had a curve at a system interchange.

Downward-slanting (and thus dancing) arrows are explicitly prohibited in the 2009 MUTCD.
Please note: All posts represent my personal opinions and do not represent those of my employer or any of its partner agencies.

Travel Mapping (updated weekly)

NE2

Does the MUTCD allow New York style fat-ass signs like this?

from http://www.alpsroads.net/roads/ny/i-87/n.html
pre-1945 Florida route log

I accept and respect your identity as long as it's not dumb shit like "identifying as a vaccinated attack helicopter".

myosh_tino

Quote from: jakeroot on January 13, 2015, 01:26:48 PM
If the MUTCD allowed modifiable arrows (so they didn't have to be 4 feet tall) we could make pretty short APL signs that were still decently effective and didn't waste so much space.

First, the current arrow-per-lane arrows are not 4 feet tall.  They are 5 1/2 to 6 feet tall depending on whether you go by the spec in the latest SHSM or the current MUTCD.

Second, who says the you have to follow the spec  :D...


This sign was put up by Caltrans on westbound CA-180 in Fresno.  By my approximations, the up arrows are only 45 inches tall which results in less wasted space on the sign panel and allows Caltrans to implement arrow-per-lane signage while keeping the 120-inch maximum guide sign panel height policy.
Quote from: golden eagle
If I owned a dam and decided to donate it to charity, would I be giving a dam? I'm sure that might be a first because no one really gives a dam.

PHLBOS

#10
Downward-slanting (and thus dancing) arrows are explicitly prohibited in the 2009 MUTCD.
Wrong, such are still allowed for exits & splits with dedicated lanes.  Scroll down to Figure 2E-14 for example.
GPS does NOT equal GOD

NE2

Quote from: PHLBOS on January 13, 2015, 02:48:36 PM
Quote from: cl94 on January 13, 2015, 01:29:12 PM
Downward-slanting (and thus dancing) arrows are explicitly prohibited in the 2009 MUTCD.
Wrong, such are still allowed for exits & splits with dedicated lanes.  Scroll down to Figure 2E-14 for example.
Wrong, those aren't slanted.
pre-1945 Florida route log

I accept and respect your identity as long as it's not dumb shit like "identifying as a vaccinated attack helicopter".

jakeroot

Quote from: PHLBOS on January 13, 2015, 02:48:36 PM
Quote from: cl94 on January 13, 2015, 01:29:12 PMThe biggest problem with the dancing arrows is that they aren't universal and induce confusion.
'Dancing' arrows have been around on highways in the U.S. long before diagrammatics and APLs.

Quote from: cl94 on January 13, 2015, 01:29:12 PM
Downward-slanting (and thus dancing) arrows are explicitly prohibited in the 2009 MUTCD.
Wrong, such are still allowed for exits & splits with dedicated lanes.  Scroll down to Figure 2E-14 for example.

Recently-erected signage along I-93 northbound at the Braintree (MA 3) split uses (mostly downward) dancing arrows.

Signage along US 3 southbound approaching I-95 in Burlington, MA

I don't see any downward-slanting arrows. Your Mass examples have the arrows facing the wrong direction (they should be pointing up).

Figure 2E-14 does not have any arrows pointing down that are also slanting. The only slanting arrows are pointing up.

Unless I'm mistaken, these are the arrows that induce confusion. The arrow in the "Indian Head" BGS is pointed ambiguously in a sideways direction.


odditude

my only experience with APL signs is on I-95 in Delaware, and they are way too tall. the ridiculous length of the arrows pushes the important information up so high you have to take your eyes off the road to look up at the signs.

PHLBOS

#14
Quote from: cl94 on January 13, 2015, 01:29:12 PM
I've since crossed out my previous post.

Quote from: jakeroot on January 13, 2015, 02:59:38 PMYour Mass examples have the arrows facing the wrong direction (they should be pointing up).
Roadman can shed some light towards why MassDOT does such.
GPS does NOT equal GOD

jeffandnicole

Based on a few examples I could find, signage costs about $25-$40 a square foot.  On projects of this magnitude, the overall cost of the additional room APL takes up is very minor.  And that would have to be weighed again the cost of traditional signage to determine how much additional APL signage would cost. We're probably talking less than $100,000 total for this Kansas project, on a project that's going to cost tens of millions.

Ned Weasel

#16
Quote from: cl94 on January 13, 2015, 01:29:12 PM
The sheer cost of each APL was mentioned. Another suggestion I heard was to adopt Ontario's option lane signage, which I agree with. If you're not familiar with Ontario's practice, they place a yellow sign at the side of the road illustrating the movements of each lane. The arrows look like APL arrows, but lanes that either do not exit or are not option lanes are not shown.

The biggest problem with the dancing arrows is that they aren't universal and induce confusion. I remember my parents being very confused when we moved to Ohio and saw them because option lanes out here, if signed at all, had normal down arrows or diagrammatics until APLs cane around. Downward-slanting arrows out here indicated when a freeway had a curve at a system interchange.

Downward-slanting (and thus dancing) arrows are explicitly prohibited in the 2009 MUTCD.

If you're interested in the I-35/I-435/US 69/K-10 project in Lenexa and Overland Park, it's worth noting that KDOT used to love dancing arrows, perhaps even more than Ohio's DOT.  KDOT used to employ dancing arrows in almost every option lane situation on freeways until sometime after the 2009 MUTCD expressly prohibited them.  Personal views on dancing arrows aside, I would say that KDOT made a rather conscientious effort to point each arrow to the lane to which it was referring, rather than using a thoughtless 45-degree angle as in the Maryland example Jake (jakeroot) shared, and, in that light, I would say KDOT was much more skillful in its design of dancing-arrow signage than many other DOTs across the country.

If the 2009 MUTCD hadn't nixed KDOT's beloved dancing arrows, I can almost guarantee you that the I-35/I-435/US 69/K-10 interchange complex would be full of them, and it would perhaps even be a contender for the most dazzling display of dancing arrows in the country, given the complexity and relatively close spacing of numerous successive option lane situations.  In fact, if you drive present-day I-435 and US 69 in Overland Park, you will see extensive, near-consistent use of dancing arrows at many interchanges.

If I were to vote for a single solution to be employed universally in option lane situations, I would agree with Zeffy and argue in favor if Minnesota's approach of using a vertical bar centered above a perfectly vertical down arrow.
"I was raised by a cup of coffee." - Strong Bad imitating Homsar

Disclaimer: Views I express are my own and don't reflect any employer or associated entity.

jakeroot

Quote from: jeffandnicole on January 13, 2015, 03:25:32 PM
Based on a few examples I could find, signage costs about $25-$40 a square foot.  On projects of this magnitude, the overall cost of the additional room APL takes up is very minor.  And that would have to be weighed again the cost of traditional signage to determine how much additional APL signage would cost. We're probably talking less than $100,000 total for this Kansas project, on a project that's going to cost tens of millions.

They're going to argue about the additional wind-load next. Keep fending them off! :-D Damn APL haters.

cl94

Quote from: jakeroot on January 13, 2015, 05:09:36 PM
Quote from: jeffandnicole on January 13, 2015, 03:25:32 PM
Based on a few examples I could find, signage costs about $25-$40 a square foot.  On projects of this magnitude, the overall cost of the additional room APL takes up is very minor.  And that would have to be weighed again the cost of traditional signage to determine how much additional APL signage would cost. We're probably talking less than $100,000 total for this Kansas project, on a project that's going to cost tens of millions.

They're going to argue about the additional wind-load next. Keep fending them off! :-D Damn APL haters.

Issue is that with stuff like this, every cent counts. A full APL sign covering all lanes could cost hundreds more than an exit sign and a pull-through. One of the ideas we had was to, in cases with >2 through lanes, cut off every through-only lane except for the one immediately adjacent to the option lane.
Please note: All posts represent my personal opinions and do not represent those of my employer or any of its partner agencies.

Travel Mapping (updated weekly)

jakeroot

#19
Quote from: cl94 on January 13, 2015, 06:42:42 PM
Quote from: jakeroot on January 13, 2015, 05:09:36 PM
Quote from: jeffandnicole on January 13, 2015, 03:25:32 PM
Based on a few examples I could find, signage costs about $25-$40 a square foot.  On projects of this magnitude, the overall cost of the additional room APL takes up is very minor.  And that would have to be weighed again the cost of traditional signage to determine how much additional APL signage would cost. We're probably talking less than $100,000 total for this Kansas project, on a project that's going to cost tens of millions.

They're going to argue about the additional wind-load next. Keep fending them off! :-D Damn APL haters.

Issue is that with stuff like this, every cent counts. A full APL sign covering all lanes could cost hundreds more than an exit sign and a pull-through. One of the ideas we had was to, in cases with >2 through lanes, cut off every through-only lane except for the one immediately adjacent to the option lane.

Or just make the sign shorter so it's both cheap and effective:






Quote from: myosh_tino on January 13, 2015, 02:35:16 PM
First, the current arrow-per-lane arrows are not 4 feet tall.  They are 5 1/2 to 6 feet tall depending on whether you go by the spec in the latest SHSM or the current MUTCD.

Jesus. That's even worse than I thought.

machias

These are the types of dancing arrows I am referring to, especially at splits such as the one depicted here (photo courtesy of John Krakoff).




Pete from Boston

Quote from: jakeroot on January 13, 2015, 12:00:55 AM
British Columbia did this along Highway 1 with the $3B gateway program. Only difference is that they use APLs regardless of the number of lanes exiting nor whether or not they are exit-only. Most interchanges have APLs now. Here's a photo that demonstrates what most junctions are signed like (ignore the unfinished bottom bit):



EDIT: Here's another sort-of-APL setup, to give you an idea of how liberally BC uses up arrows:



I like this two-sign setup much better than the weak thin dividing line that reaches halfway into the field and doesn't seem to have any relationship to the rest of the sign. 

I don't mean to dwell on it, but every time I see that line it feels like it was late and the designer was tired and had an early-morning deadline to make and kind of gave up.


NE2

Quote from: Pete from Boston on January 13, 2015, 09:05:15 PM
I don't mean to dwell on it, but every time I see that line it feels like it was late and the designer was tired and had an early-morning deadline to make and kind of gave up.
The primary use case for APL signs is when you have a lane that goes straight and right. This double arrow goes right under the dividing line.
pre-1945 Florida route log

I accept and respect your identity as long as it's not dumb shit like "identifying as a vaccinated attack helicopter".

jeffandnicole

Quote from: cl94 on January 13, 2015, 06:42:42 PM
Quote from: jakeroot on January 13, 2015, 05:09:36 PM
Quote from: jeffandnicole on January 13, 2015, 03:25:32 PM
Based on a few examples I could find, signage costs about $25-$40 a square foot.  On projects of this magnitude, the overall cost of the additional room APL takes up is very minor.  And that would have to be weighed again the cost of traditional signage to determine how much additional APL signage would cost. We're probably talking less than $100,000 total for this Kansas project, on a project that's going to cost tens of millions.

They're going to argue about the additional wind-load next. Keep fending them off! :-D Damn APL haters.

Issue is that with stuff like this, every cent counts. A full APL sign covering all lanes could cost hundreds more than an exit sign and a pull-through. One of the ideas we had was to, in cases with >2 through lanes, cut off every through-only lane except for the one immediately adjacent to the option lane.

And that's what I'm referring to.  On projects like these, where tens, if not hundreds, of millions of dollars are being spent, hundreds of dollars are like pennies in the sofa.  DOT officials will be concerned with today's requirements and getting the public and local officials to agree to the project, not whether a few hundred dollars are spent on additional signage.

If they can save a few million on design techniques, they'll be willing to listen.  But at the same time, if a group of people protest how a ramp affects their neighborhood, the DOT may redesign the ramp.  It may add a million or two to the total cost, but it's worth it in the end if everyone is satisfied and it doesn't overly impact other things associated with the project.

roadfro

Quote from: jeffandnicole on January 13, 2015, 09:50:10 PM
Quote from: cl94 on January 13, 2015, 06:42:42 PM
Quote from: jakeroot on January 13, 2015, 05:09:36 PM
Quote from: jeffandnicole on January 13, 2015, 03:25:32 PM
Based on a few examples I could find, signage costs about $25-$40 a square foot.  On projects of this magnitude, the overall cost of the additional room APL takes up is very minor.  And that would have to be weighed again the cost of traditional signage to determine how much additional APL signage would cost. We're probably talking less than $100,000 total for this Kansas project, on a project that's going to cost tens of millions.

They're going to argue about the additional wind-load next. Keep fending them off! :-D Damn APL haters.

Issue is that with stuff like this, every cent counts. A full APL sign covering all lanes could cost hundreds more than an exit sign and a pull-through. One of the ideas we had was to, in cases with >2 through lanes, cut off every through-only lane except for the one immediately adjacent to the option lane.

And that's what I'm referring to.  On projects like these, where tens, if not hundreds, of millions of dollars are being spent, hundreds of dollars are like pennies in the sofa.  DOT officials will be concerned with today's requirements and getting the public and local officials to agree to the project, not whether a few hundred dollars are spent on additional signage.

If they can save a few million on design techniques, they'll be willing to listen.  But at the same time, if a group of people protest how a ramp affects their neighborhood, the DOT may redesign the ramp.  It may add a million or two to the total cost, but it's worth it in the end if everyone is satisfied and it doesn't overly impact other things associated with the project.

JeffandNicole's comment doesn't take into account the structural issues with mounting a much larger sign. A larger sign means potential additional hardware for mounting, and definitely increased weight of the sign--which, could mean greater material cost, not to mention additional design work if the DOT doesn't have a sign structure standard that supports APL. So you're looking at possible thousands (or 10s of thousands) per sign to implement APL when all costs are added. In a project like the ones pictured, it could be significant money.

One example: NDOT's first real APL signs were on I-80 in Reno. They ended up using monotube sign bridges, because the NDOT standard truss was not designed for APLs (which are about 2-3 times the height of NDOT standard signs). These I-80 signs were the first monotube sign bridges installed in Nevada.
Roadfro - AARoads Pacific Southwest moderator since 2010, Nevada roadgeek since 1983.



Opinions expressed here on belong solely to the poster and do not represent or reflect the opinions or beliefs of AARoads, its creators and/or associates.