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Author Topic: Arrow-Per-Lane (APL) signs  (Read 23552 times)

cl94

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Re: Arrow-Per-Lane (APL) signs
« Reply #25 on: January 13, 2015, 11:01:13 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.

I'll add to that. At least one of NYSTA's APL installations is so tall that it features a beefy bracing system that extends up from the gantry along the width of the sign. Given where it is (Exit 53), they have to consider high winds when designing the signs. The somewhat-new New York truss can handle APLs, but the sheer height is something that they cannot manage alone.
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Re: Arrow-Per-Lane (APL) signs
« Reply #26 on: January 13, 2015, 11:07:55 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.

I'll add to that. At least one of NYSTA's APL installations is so tall that it features a beefy bracing system that extends up from the gantry along the width of the sign. Given where it is (Exit 53), they have to consider high winds when designing the signs. The somewhat-new New York truss can handle APLs, but the sheer height is something that they cannot manage alone.

I'm surprised more states haven't adopted monotube structures (a la Washington) where they work with all types of signs of all heights. No thinking about sign height, blah blah blah. Just install the structure, attach the sign, DONE.

(^^ am I over-simplifying the process?)
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cl94

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Re: Arrow-Per-Lane (APL) signs
« Reply #27 on: January 13, 2015, 11:15:43 PM »

It has nothing to do with the type of structure, it's having to design for 120 mph winds and a 140 degree temperature swing. New York has very strict structural requirements. It's wind bracing more than anything else. If a sign is taller, the wind exerts a larger moment on the sign and supports. Simply putting up a monotube won't fix it and those present their own issues.

I'm not against the use of APLs for option lanes. I just think the current requirements are excessive, especially when you have to consider climate conditions, environmental sustainability when it comes to the use of materials, and overall cost. I've said it before and I'll say it again: people I've spoken to in practice tell me that every cent in every contract matters.
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Re: Arrow-Per-Lane (APL) signs
« Reply #28 on: January 14, 2015, 12:02:21 AM »

For fun, I did a mockup of an interchange near me in both the Minnesota DOT method of signing option lanes, and with the traditional FHWA APL approach: (Interchange Link)





While both signs are rather wide, you may notice that the APL version is most definitely taller than the MNDOT method.
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Re: Arrow-Per-Lane (APL) signs
« Reply #29 on: January 14, 2015, 12:31:49 AM »

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.

That is true, and my mind completely skipped over that fact because that damn little lost line bugs me so much.
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jakeroot

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Re: Arrow-Per-Lane (APL) signs
« Reply #30 on: January 14, 2015, 01:05:56 AM »

While both signs are rather wide, you may notice that the APL version is most definitely taller than the MNDOT method.

It's all how you sign it ... this sign is just a hair over 9 feet tall.

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Re: Arrow-Per-Lane (APL) signs
« Reply #31 on: January 14, 2015, 02:13:22 AM »

To piggyback on what Jeffy posted, here are three sign drawings following different specs…

#1 - Classic Caltrans (option lane with down-arrows)

#2 - Arrow-per-Lane Caltrans-style

#3 - Vanilla MUTCD (but retained California-style exit "tab")

Oddly enough, even though the FHWA APL is narrower, it is still a larger sign square footage wise.  The two California signs are 475 sq ft (47.5' x 10') while the FHWA APL is 602 sq ft (43' x 14').  With that said, I guess you can put me firmly in the anti-APL camp.  The signs are way to big and waste too much sign panel space.

It's all how you sign it ... this sign is just a hair over 9 feet tall.



I think there's something wrong with your scale.  Operating under the assumption that the up-arrows are 66", the legend is 16" and the route shield is 36", your sign should should measure at least 11 1/2 feet (I'm also assuming there's 12" between the bottom of the sign and the arrows and between Trenton and the route shield and between the route shield and the top of the sign).  FWIW, the signs in my drawing are to correct scale.
« Last Edit: January 14, 2015, 02:16:32 AM by myosh_tino »
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jakeroot

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Re: Arrow-Per-Lane (APL) signs
« Reply #32 on: January 14, 2015, 02:26:26 AM »

I think there's something wrong with your scale.  Operating under the assumption that the up-arrows are 66", the legend is 16" and the route shield is 36", that should should measure at least 11 1/2 feet (I'm also assuming there's 12" between the bottom of the sign and the arrows and between Trenton and the route shield and between the route shield and the top of the sign).  FWIW, the signs in my drawing are to correct scale.

I've recently added the MUTCD arrowhead to my Illustrator library, so I've been having some trouble keeping arrow scales in line (for what it's worth, the arrows are custom made -- the right arrow, for example). At this point, I'm more interested in the constant of the arrows: the width of the stroke. Also, the arrows are not full height. They are shortened (even the outer ones that could feasibly be full height).

Here's a slightly repaired version:

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Re: Arrow-Per-Lane (APL) signs
« Reply #33 on: January 14, 2015, 05:50:50 AM »

I offer this even more slimmed down version, it's about as short as APL's can get.

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Re: Arrow-Per-Lane (APL) signs
« Reply #34 on: January 14, 2015, 11:36:18 AM »


I'm surprised more states haven't adopted monotube structures (a la Washington) where they work with all types of signs of all heights. No thinking about sign height, blah blah blah. Just install the structure, attach the sign, DONE.

(^^ am I over-simplifying the process?)


In a word - yes.  For larger sign sizes (i.e. APL and diagrammatics), when you consider the panel dimensions, loading requirements, wind design, trichord or box truss type structures can be fabricated at lower cost than equivalent monotube supports.  Also, monotube supports require specialty hardware for sign attachment, and have no redundancy, making them more likely to collapse should the panels or structure be hit by a raised dump body or overheight truck.
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Re: Arrow-Per-Lane (APL) signs
« Reply #35 on: January 14, 2015, 03:13:24 PM »

I'm surprised more states haven't adopted monotube structures (a la Washington) where they work with all types of signs of all heights. No thinking about sign height, blah blah blah. Just install the structure, attach the sign, DONE.

(^^ am I over-simplifying the process?)

In a word - yes.  For larger sign sizes (i.e. APL and diagrammatics), when you consider the panel dimensions, loading requirements, wind design, trichord or box truss type structures can be fabricated at lower cost than equivalent monotube supports.  Also, monotube supports require specialty hardware for sign attachment, and have no redundancy, making them more likely to collapse should the panels or structure be hit by a raised dump body or overheight truck.

If the state decided to completely commit to monotubes, would the costs fall a little (buying in bulk and all)?
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Re: Arrow-Per-Lane (APL) signs
« Reply #36 on: January 14, 2015, 03:28:57 PM »

If memory serves, the main Johnson County Gateway contract (being done as a design-build) is budgeted for around $250 million.  If the Springfield Interchange is taken as representative (10% of contract cost attributed to signing, including structures), then the signing shown in those rollplots is probably around $25 million of work.  And because of the structural element arising from the heavy use of APL diagrammatics, the total amount may be quite a bit higher (Springfield had conventional signs).
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jakeroot

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Re: Arrow-Per-Lane (APL) signs
« Reply #37 on: January 14, 2015, 03:44:29 PM »

So, the monotube works in less locations, and is more expensive. Why does anyone use it?
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Re: Arrow-Per-Lane (APL) signs
« Reply #38 on: January 14, 2015, 03:56:32 PM »

I'm surprised more states haven't adopted monotube structures (a la Washington) where they work with all types of signs of all heights. No thinking about sign height, blah blah blah. Just install the structure, attach the sign, DONE.

(^^ am I over-simplifying the process?)

In a word - yes.  For larger sign sizes (i.e. APL and diagrammatics), when you consider the panel dimensions, loading requirements, wind design, trichord or box truss type structures can be fabricated at lower cost than equivalent monotube supports.  Also, monotube supports require specialty hardware for sign attachment, and have no redundancy, making them more likely to collapse should the panels or structure be hit by a raised dump body or overheight truck.

If the state decided to completely commit to monotubes, would the costs fall a little (buying in bulk and all)?

No - there's rarely a one-size-fits-all (or most).  Exact placement of the supports can vary, so exact widths will vary as well.
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Re: Arrow-Per-Lane (APL) signs
« Reply #39 on: January 14, 2015, 04:06:41 PM »

It is more expensive for states that don't currently use monotubes because there are ton of upfront costs for design (tube itself, the base/foundation, mounting hardware, etc) and testing (wind, temperature change, etc).  I don't think it's a simple as saying, "let's use WSDOT's monotube designs as-is."

Caltrans does use monotubes from time to time although their gantry of choice is still the truss.  I'm not entirely sure what the criteria is for using a monotube over a truss but even with monotubes, the maximum sign height is still 120 inches and all signs on the monotube must be the same height.  To take things a step further, Caltrans specifies 6 different tube sizes (diameter and thickness of the pipe) depending on sign panel height, post height and the span length.  To see these specs go to http://www.dot.ca.gov/hq/esc/oe/project_plans/HTM/stdplns-US-customary-units-new10.htm#overhead and scroll down to "OVERHEAD SIGNS (TUBULAR)".  Click on "click to view" to see a PDF of the detail.
« Last Edit: January 14, 2015, 04:17:29 PM by myosh_tino »
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Re: Arrow-Per-Lane (APL) signs
« Reply #40 on: January 14, 2015, 05:19:22 PM »

So, the monotube works in less locations, and is more expensive. Why does anyone use it?
In one word - aesthetics.  Which to me has always been stupid, because aesthetics are totally subjective and, thus, a totally irrational reason to intentionally use more expensive hardware.  Especially when color galvanizing the support structures achieves the same effect at less cost.
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jakeroot

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Re: Arrow-Per-Lane (APL) signs
« Reply #41 on: January 14, 2015, 05:45:21 PM »

So, the monotube works in less locations, and is more expensive. Why does anyone use it?

In one word - aesthetics.  Which to me has always been stupid, because aesthetics are totally subjective and, thus, a totally irrational reason to intentionally use more expensive hardware.  Especially when color galvanizing the support structures achieves the same effect at less cost.

Aesthetics is absolutely objective. But there are places where DOTs secondary interest is aesthetics. I can only assume that (in my case) WSDOT groups the gantry into the second group, and thus the more attractive gantry option is selected (given that the price difference is minimal but, in their opinion, is the preferable option given the more "airey" feeling they have).

Here is a recently widening section of freeway near Seattle:

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Re: Arrow-Per-Lane (APL) signs
« Reply #42 on: January 15, 2015, 11:45:12 AM »

So, the monotube works in less locations, and is more expensive. Why does anyone use it?
In one word - aesthetics.  Which to me has always been stupid, because aesthetics are totally subjective and, thus, a totally irrational reason to intentionally use more expensive hardware.  Especially when color galvanizing the support structures achieves the same effect at less cost.
One other advantage that monotube/pipe gantries have (such was commented on another thread) is that such are less prone to graffiti/vandalism.  It's more of a challenge to climb up a monotube/pipe gantry than a truss gantry (which is similar to a set of monkeybars in terms of climbing).
« Last Edit: January 15, 2015, 01:47:25 PM by PHLBOS »
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Re: Arrow-Per-Lane (APL) signs
« Reply #43 on: January 15, 2015, 12:47:00 PM »

One other advantage that monotube/pipe gantries have (such was commented on another thread) is that such are less prone to graffiti/vandalism.  It's more of a challenge to climb up a monotube/pipe gantry than a truss gantry (which is similar to a set of monkeybars in terms of climbing).

That's not the case in California, Nevada and Arizona.  Truss gantries in these states use single pole supports and yet graffiti is still a problem (at least in California it is).





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Re: Arrow-Per-Lane (APL) signs
« Reply #44 on: January 15, 2015, 12:50:46 PM »

So, the monotube works in less locations, and is more expensive. Why does anyone use it?
In one word - aesthetics.  Which to me has always been stupid, because aesthetics are totally subjective and, thus, a totally irrational reason to intentionally use more expensive hardware.  Especially when color galvanizing the support structures achieves the same effect at less cost.
IMO truss gantries look better than monotubes.
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Re: Arrow-Per-Lane (APL) signs
« Reply #45 on: January 15, 2015, 01:47:06 PM »

One other advantage that monotube/pipe gantries have (such was commented on another thread) is that such are less prone to graffiti/vandalism.  It's more of a challenge to climb up a monotube/pipe gantry than a truss gantry (which is similar to a set of monkeybars in terms of climbing).

That's not the case in California, Nevada and Arizona.  Truss gantries in these states use single pole supports and yet graffiti is still a problem (at least in California it is).
I mentioned less prone to vandalism not 100% immune, there is a difference.  Additionally, I was primarily referring to montube pipe gantries not single-pole-supported truss gantries.

Another gantry-magnet for vandals are those catwalks (intended for maintenance workers & support lights) shown in two of your posted-photos.
« Last Edit: January 15, 2015, 01:55:16 PM by PHLBOS »
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Re: Arrow-Per-Lane (APL) signs
« Reply #46 on: January 15, 2015, 04:18:10 PM »

One other advantage that monotube/pipe gantries have (such was commented on another thread) is that such are less prone to graffiti/vandalism.  It's more of a challenge to climb up a monotube/pipe gantry than a truss gantry (which is similar to a set of monkeybars in terms of climbing).

That's not the case in California, Nevada and Arizona.  Truss gantries in these states use single pole supports and yet graffiti is still a problem (at least in California it is).
I mentioned less prone to vandalism not 100% immune, there is a difference.  Additionally, I was primarily referring to montube pipe gantries not single-pole-supported truss gantries.

Another gantry-magnet for vandals are those catwalks (intended for maintenance workers & support lights) shown in two of your posted-photos.

If someone can get up a vertical round pipe, they can inch along a horizontal pipe up top. If someone is determined, they will tag it.
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Re: Arrow-Per-Lane (APL) signs
« Reply #47 on: January 15, 2015, 04:46:28 PM »

Monotube gantries that WSDOT uses are an ass-ton cheaper than the fu-fu artsy fartsy gantries Wisconsin and Texas use.  Honestly, I prefer the minimalist aesthetics.

Monotube designs are generally avoided in high-wind areas.  On the other hand, truss designs can be less flexible. 

« Last Edit: January 15, 2015, 04:51:04 PM by KEK Inc. »
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Re: Arrow-Per-Lane (APL) signs
« Reply #48 on: January 15, 2015, 04:58:43 PM »

Yes, truss designs are generally less flexible than monotube designs.  However, properly designed truss structures have redundant load paths, so they are able to more easily dissapate wind than monotube structures are.
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Re: Arrow-Per-Lane (APL) signs
« Reply #49 on: January 15, 2015, 05:26:57 PM »

Yes, truss designs are generally less flexible than monotube designs.  However, properly designed truss structures have redundant load paths, so they are able to more easily dissapate wind than monotube structures are.

If there's high wind, you want some level of rigidity. Truss structures provide a great amount of strength while allowing air to pass through, therefore wind has less surface area for the wind to act on.
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