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Performance and Value

Signs made with higher performance reflective sheeting are more visible and help improve safety. Report No. FHWA-HRT-07-042 confirms that over the life of a sign, use of higher performance reflective sheeting may actually cost less.
Signs deteriorate at different rates. Age, location, sun exposure and sheeting type all affect a sign’s useful lifespan. The best measure of the cost of a sign is its life-cycle cost (i.e. the cost of the sign divided by its useful life). Factor in labor, hardware, administrative expenses and other costs that are incurred each time a sign needs replacement and the savings for longer-lasting signs get even better.


Sheeting Attributes Engineer Grade Reflective Sheeting 3M™ High Intensity Prismatic Reflective Sheeting 3M™ Diamond Grade™ DG³ Reflective Sheeting
Overall Performance I III, IV XI
Retroreflectivity
(0.5°, -4°)
30 cd/lux/m² 200 cd/lux/m² 400 cd/lux/m²
ASTM Type(s) May not meet federal minimum retroreflectivity levels over the life of the sign Good Excellent
Cost of Sign* $35.94 $40.63 $55.50
Expected Life 7 years 10 years 12 years
Cost Per Year $5.13 $4.06 $4.63
*Example only—actual costs may vary.

Better, brighter signs can help agencies save money in other ways, too. State departments of transportation across the U.S. have initiatives to improve guide sign visibility and save taxpayer dollars. Many are finding one solution that helps achieve both goals by upgrading to guide signs made with high performance, “full cube” reflective sheeting from 3M, while at the same time cutting maintenance and energy costs by turning off guide sign lighting.
The Illinois Department of Transportation (IDOT) announced in 2006 that it would begin switching out all overhead signs on the state’s roadways to use high performance retroreflective sheeting (meeting IDOT Type ZZ) to improve visibility and that the new signs would also save the state money by allowing IDOT to remove lighting fixtures used on overhead signs. New signs were put up as old ones needed to be replaced, so the change-over to the more highly reflective sheeting was expected to take at least 10 years. There are costs involved in upgrading to the new sheeting, but the state could see savings of nearly $1 million a year in light maintenance and energy costs.
The Hawaii Department of Transportation installed guide signs made with high performance retroreflective sign sheeting on the Moanalua Freeway corridor. The old signs were already slated for replacement, and the new signs no longer require lighting. Energy and maintenance cost reductions on this one road corridor alone are significant. Long term electrical savings amount to about $14,000 a year. Maintenance work that goes into replacing the overhead light bulbs is estimated at $30,000 a year. This figure does not include user costs and inconvenience from road closures associated with the maintenance work.
The Wisconsin Department of Transportation (WisDOT) is evaluating the use of high performance retroreflective sheeting on guide signs near Madison as a method to turn off sign lighting in most situations to create significant energy and maintenance savings. WisDOT is expanding this performance-based sign program in the Milwaukee area including upgrade of guide signs and turning off sign lighting.
WisDOT conducted a nationwide survey to identify guide sign lighting policies and actions other states are taking to address this issue. Thirty states responded to the survey with most states indicating that they are considering some form of a guide sign lighting deactivation program except in certain situations such as locations with frequent fog problems or where road segment geometries may require lighting to supplement vehicle headlights.