AARoads Forum

National Boards => General Highway Talk => Topic started by: mariethefoxy on August 07, 2015, 12:17:40 AM

Title: Tilted Overhead Signs
Post by: mariethefoxy on August 07, 2015, 12:17:40 AM
I noticed in many of the new england states, particularly Connecticut, Massachusetts, and New Hampshire, also in Pennsylvania, they mount the overhead signs so they are tilted forward (Rhode Island does this too but not at the same level of consistency) I was wondering why they do that, is there some advantage to it, since many other states don't do that.
Title: Re: Tilted Overhead Signs
Post by: davewiecking on August 07, 2015, 08:32:25 AM
Makes it harder for snow to stick??
Title: Re: Tilted Overhead Signs
Post by: jeffandnicole on August 07, 2015, 08:46:13 AM
Doubt that's the reason.  Snow rarely sticks to those signs.  Otherwise all northern states would have this issue.  Georgia tilts them slightly as well.
Title: Re: Tilted Overhead Signs
Post by: roadman on August 07, 2015, 09:10:02 AM
Quote from: mariethefoxy on August 07, 2015, 12:17:40 AM
I noticed in many of the new england states, particularly Connecticut, Massachusetts, and New Hampshire, also in Pennsylvania, they mount the overhead signs so they are tilted forward (Rhode Island does this too but not at the same level of consistency) I was wondering why they do that, is there some advantage to it, since many other states don't do that.
Placing a slight forward tilt on overhead signs has been Massachusetts standard practice since the late 1960s.  I was told many years ago by a MassDPW sign engineer that the principal intent of this tilt was not to minimize snow accumulation, but to provide for better visibilty at night.  However, given the improvements in retro-reflective sheeting since this standard was first adopted, it would be interesting to see if the 'tilt' still makes a noticeable difference in visibility (perhaps a subject for a TRB or TTI research study?).
Title: Re: Tilted Overhead Signs
Post by: thenetwork on August 07, 2015, 11:16:30 AM
The overhead signs used around Detroit Metro Airport were tilted when I was last there in the early 90s.  With the airport practically rebuilt and a south entrance added since, I'm not sure if they still do that practice.

Otherwise, PA and MA were the two states that came to mind when I first saw the post.
Title: Re: Tilted Overhead Signs
Post by: Ian on August 07, 2015, 12:19:31 PM
When I was in New Brunswick earlier this year, I noticed that most of their overheads were actually tilted upwards in stead of downwards. Any reason why that is? I've seen it done with older overheads in Rhode Island as well.
Title: Re: Tilted Overhead Signs
Post by: ekt8750 on August 07, 2015, 12:24:04 PM
Forward tilting reduces sun glare too.
Title: Re: Tilted Overhead Signs
Post by: lordsutch on August 09, 2015, 12:34:39 AM
Most modern installations in Georgia also have what appears to be a 10 degree tilt or so. It probably helps ensure that the reflected light from headlights onto prismatic sheeting mostly goes back toward the road traffic, rather than bouncing up into the sky where it's not very useful. (I doubt snow or ice accumulation has much to do with it.)
Title: Re: Tilted Overhead Signs
Post by: Scott5114 on August 09, 2015, 07:53:50 PM
Kansas also tilts their signs. To my knowledge, OK, MO, and TX do not.
Title: Re: Tilted Overhead Signs
Post by: Marc on February 25, 2016, 12:48:39 AM
Quote from: Scott5114 on August 09, 2015, 07:53:50 PM
Kansas also tilts their signs. To my knowledge, OK, MO, and TX do not.
A few districts in Texas do. Dallas, Fort Worth, and [maybe] El Paso districts. Though, they never seem consistent with it.

Here are the states I've been to that tilt or once tilted:

Alabama (down)
Arkansas (new installations tilted down)
Georgia (down)
Louisiana (formerly up, now down)
Mississippi (formerly up, no longer tilt)
New Mexico (down)
South Carolina (up)
Tennessee (down)
Texas (down in some districts)

I believe the primary reason to tilt down is to prevent the retroreflective sheeting from appearing "washed out" when the sun hits it just right. Have you ever driven in the morning or evening hours and encountered a sign that was illegible because of the way the sun was reflecting on it? To my knowledge, this prevents that from happening. If I had my way, every state would be required to do this. Plus, I think it looks kinda cool/more modern.
Title: Re: Tilted Overhead Signs
Post by: PHLBOS on February 25, 2016, 09:14:41 AM
Quote from: Ian on August 07, 2015, 12:19:31 PM
When I was in New Brunswick earlier this year, I noticed that most of their overheads were actually tilted upwards in stead of downwards. Any reason why that is? I've seen it done with older overheads in Rhode Island as well.
Many older BGS' along I-95/MA 128 (both from the 70s and from the 90s) from the I-90/MA 30 interchanges down to either MA 135 or Great Plain Ave. interchanges had an upward tilt as well.

My guess is that somebody must have read the detail sheet or shop drawings upside down when the original BGS (from the early 70s, prior to MA 128 becoming a part of I-95).  The main reason why the 90s-era sign replacements did similar were due to the older gantries and mounting hardware were essentially reused for the new sign panels.
Title: Re: Tilted Overhead Signs
Post by: Rothman on February 25, 2016, 09:27:25 AM
Quote from: Marc on February 25, 2016, 12:48:39 AM
Quote from: Scott5114 on August 09, 2015, 07:53:50 PM
Kansas also tilts their signs. To my knowledge, OK, MO, and TX do not.
A few districts in Texas do. Dallas, Fort Worth, and [maybe] El Paso districts. Though, they never seem consistent with it.

Here are the states I've been to that tilt or once tilted:

Alabama (down)
Arkansas (new installations tilted down)
Georgia (down)
Louisiana (formerly up, now down)
Mississippi (formerly up, no longer tilt)
New Mexico (down)
South Carolina (up)
Tennessee (down)
Texas (down in some districts)


Didn't the NJ Turnpike tilt some of their signs?
Title: Re: Tilted Overhead Signs
Post by: Jardine on February 25, 2016, 01:26:12 PM
I bet it has something to do with washing machine tilt . . .

:sombrero:
Title: Re: Tilted Overhead Signs
Post by: roadman65 on May 06, 2024, 04:34:12 AM
https://www.flickr.com/photos/54480415@N08/53691142625
Thought I would post this of a full spanning cantilever that's in use near Largo, Florida. I think it's neat that it can support itself the entire width of the roadway.

Many places use full gantries for even part of this distance.
Title: Re: Tilted Overhead Signs
Post by: Big John on May 06, 2024, 04:46:09 AM
^^ Does Georgia still have the policy of no cantilever gantries?
Title: Re: Tilted Overhead Signs
Post by: freebrickproductions on May 08, 2024, 03:26:09 AM
Quote from: Big John on May 06, 2024, 04:46:09 AM^^ Does Georgia still have the policy of no cantilever gantries?

Doesn't look like it (https://www.google.com/maps/@33.7883591,-84.3909603,3a,59.4y,16.16h,98.66t/data=!3m6!1e1!3m4!1sUCGUIhBOPwf4lUXDJNv_tw!2e0!7i16384!8i8192?entry=ttu), unless they made an exception for APLs.

Unless I misunderstood what you're describing and are talking about something like the one in roadman's post.
Title: Re: Tilted Overhead Signs
Post by: Scott5114 on May 08, 2024, 05:57:01 AM
"Cantilever gantries" usually refer to the ones only supported on one side.
Title: Re: Tilted Overhead Signs
Post by: steviep24 on May 08, 2024, 06:32:13 PM
The overhead signs at Greater Rochester International Airport (ROC) are tilted.

https://www.google.com/maps/@43.1298733,-77.6633109,3a,30y,265.63h,99.46t/data=!3m6!1e1!3m4!1sO5W51nP2CCT1kTdjsqWI8g!2e0!7i16384!8i8192?authuser=0&entry=ttu