How long should retroreflective signs last?

[tolbs17]

architect77 mentioned in the "North Carolina" board and it was in this thread about the fading I-540 signs near Highway 1 (and I did see them after my recent trip to Raleigh), and are due for a replacement.

Retroreflective should last 20 years according to this link - http://www.trafficsign.us/signsheet.html

Single-layer glass bead sheetings usually fail by gradually losing their retroreflective intensity. This is due to increasing opacity of the pigmented material caused by ultraviolet ray exposure due to sunlight. This can result in a sign that looks good in daytime but is difficult to read at night. After extended exposure (20+ years), this sheeting will crack and peel from the sign substrate.   

But when looking at these overhead signs, which are nearly 15 years old, they reached the end of their life span and need replacement surprisingly. The older ones along US-264 from Zebulon to Wilson, US 64 from Zebulon to Rocky Mount, and pretty much all of I-95 did better!

https://www.google.com/maps/@35.8607013,-78.5473176,3a,15y,346.95h,92.07t/data=!3m7!1e1!3m5!1s-qqQIySom8E0efETHF8clA!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3D-qqQIySom8E0efETHF8clA%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D104.005806%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192!5m1!1e1

https://www.google.com/maps/@35.853995,-78.5287258,3a,43.2y,104.03h,100.32t/data=!3m7!1e1!3m5!1sdQesmZYDxjVICLgQBU6EKQ!2e0!5s20211001T000000!7i16384!8i8192!5m1!1e1

https://www.google.com/maps/@35.8541237,-78.5280378,3a,45.7y,298.03h,106.48t/data=!3m6!1e1!3m4!1sdkP_Y_X562u7yrXSWsLcoQ!2e0!7i16384!8i8192!5m1!1e1

Looking at another article, - https://en.wikipedia.org/wiki/Button_copy

In contrast, signs made out of retroreflective sheeting are expected to last only around 15 years.

So the signs along I-540 (near Highway 1) basically reached the end of their lifespan. But looking over here which is an older section, these are in better shape! It might be some poor design or some first introduction to retroreflective sheeting to the ones near US-1, (as there's no lighting on them compared to the other ones I linked) I guess that's how it is...

When looking at both links, they are expected to last only 15-20 years.

In 2005, I think NCDOT started the idea about eliminating overhead sign lighting and the ones along I-540 near Highway 1 are one of the very first ones without lighting.

I'm sure they'll get replaced. There were already some fading signs along I-540 near Highway 1 and these are not the only ones fading and they were replaced.

__________________________

Edit: There's more here too

https://www.google.com/maps/@35.7954959,-78.5149786,3a,23.4y,83.47h,99.3t/data=!3m6!1e1!3m4!1sFzFwhf0FzpwlQ8zonE8lAA!2e0!7i16384!8i8192!5m1!1e1

https://www.google.com/maps/@35.7956929,-78.5143399,3a,71.9y,270.49h,100.65t/data=!3m6!1e1!3m4!1sjlcnVuHcKEXO5F4iH3SN-A!2e0!7i16384!8i8192!5m1!1e1

[Bitmapped]

There are two different factors in play with sign lifespans - how long the retroreflectivity lasts and how long the characters hold up. Sun exposure affects both, but I've seen plenty of signage where the signs are still retroreflective but the letters are deteriorating, and also plenty where the opposite has taken place.

WVDOH generally uses a 25-year replacement cycle for complete replacement of signage along an Interstate corridor, although many individual signs get replaced sooner than that due to physical damage from collisions or due to needing updated messages. Green and blue signs seem to last longer. Brown signs tend to fade much faster.

In Ohio, I've seen stretches of signage that are 10-years old where retroreflectivity on letters has already failed. The signs look fine in daylight, but at night, the message is illegible.

[kalvado]

As for UV, locality and orientation should play a role. I bet that north-facing signs on I-87 near Canadian border would last a bit more than south facing signs in Denver or Phoenix.

[Max Rockatansky]

I've seen colored vinyl shields fade in less than five years in Arizona if they were exposed high amounts of direct sunlight.  Certain colors like the brown AZ 202 shields were infamous for fade and even red doesn't seem to hold up well to intense sun.  I thought the blue AZ 101 shields were basically on par with the life span of the blue coloring in Interstate shields.

Interestingly my back yard is kind of a test bed for old shields and how they respond to high levels of heat.  Some of the Michigan Trunkline shields that had a separate vinyl block M haven't respond well to the heat.  In the case of the M-44 shield the block M is about to peel off completely from heat exposure.  Single vinyl sheets seen to do fine so long as they don't face the sun directly the bulk of the day.  I have the more valuable, painted, button copy and color sensitive stuff in my garage. 

Interestingly I've found painted shields hold up really well to sun/heat along with vinyl shields on plywood.  I guess that shouldn't be a surprise given both were common to high heat/arid environments until fairly recently. 

[jeffandnicole]

Just wondering... What makes you think those signs are 15 years old?

[tolbs17]

Just wondering... What makes you think those signs are 15 years old?

They were installed in late 2006 early 2007, and now they are faded.

[Mergingtraffic]

With the new technology you'd think signs could last longer than 20-25 years.  This sign was installed in 1969 (or close to it) and still holds up well. 
Granted it's old technology but sometimes old technology lasts longer.

[tolbs17]

With the new technology you'd think signs could last longer than 20-25 years.  This sign was installed in 1969 (or close to it) and still holds up well. 
Granted it's old technology but sometimes old technology lasts longer.

Button copy signs are expected to last 40 years, but there's disadvantages to those signs as well... and it's that they are not as easy to read at night.

[Occidental Tourist]

Some of the ones in SoCal started delaminating after a couple of years.  I'm looking at you Orange Crush and the 605 south.

[Max Rockatansky]

Some of the ones in SoCal started delaminating after a couple of years.  I'm looking at you Orange Crush and the 605 south.

Are you sure it just isn't the vandalism peel off film layers?  They tend to peel off locally in the summer in the Central Valley but the vinyl underneath is unaffected.

[SkyPesos]

I don't know how old these signs are, but here's two on I-275 in OH that are in pretty bad shape:

[tolbs17]

I don't know how old these signs are, but here's two on I-275 in OH that are in pretty bad shape:

They look like button-copy signs.

[SkyPesos]

They look like button-copy signs.

They're not. Check GSV.

[wriddle082]

Lots of BGS's along I-77 here in the Columbia, SC area had peeling letters.  I'm thinking they were only around 15 years old (probably the last batch ever made to feature the old plain black and white square/rectangle state route shields), but mostly faced west and south in generally high humidity around 9 months out of the year.  This issue made the local news, and SCDOT let out a contract to replace them earlier this year.  I think all of the worst ones have since been replaced.

[wanderer2575]

I don't know how old these signs are, but here's two on I-275 in OH that are in pretty bad shape:

All the signs along I-280 between the Ohio Turnpike and OH-2 look exactly the same as these; the retroreflectivity has failed and the signs are near-impossible to read at night.  I don't know for sure but I want to say they're not more than a dozen or so years old.  (Plus they're badly-designed Clearview.)

[tolbs17]

They look like button-copy signs.

They're not. Check GSV.

Any specific part of I-275 or all of it?

[SkyPesos]

They look like button-copy signs.

They're not. Check GSV.

Any specific part of I-275 or all of it?

Mostly the part between US 27 (exit 33) and Winton Rd (Exit 39). The reflective things on signs after that are pretty good, despite both sets using the same style of BGS (and yes, Ohio have multiple styles).