Shield symbols direct road users to the right lanes near interchanges.
Pavement messages that use numbers or letters to give road users information about school zones or other directional help for decades. UDOT is using a fairly new technology to apply thermoplastic markings in the shape of shields to direct drivers to the correct lane at interchanges.
Shields are easily identifiable symbols that drivers know to represent interstates. The giant stickers are easy to see during the day and retroreflective for good visibility at night. Studies show that the shields are helpful and evaluations indicated the markings are also durable.
Pavement markings provide another visual clue to drivers besides signs. Drivers who have difficulty interpreting signs may make sudden lane changes and those movements are known to cause crashes. The thermoplastic shields are meant to give drivers a recognizable symbol as further advanced notice about which lane leads to the desired route.
Research conducted by the Texas Transportation Institute at Texas A and M University shows that road users prefer the shield or other symbol markings over plain numbers. Participants of the study, representing a broad cross section of road users, viewed photos of roadways with symbols or numbers representing freeway types and routes.
Ninety three percent of the participants preferred the symbol type of pavement marking, including shields, as opposed to number only markings. When asked, participants stated that the symbols were colorful, more easily identified and helped identify highway type.
UDOT installed the first shield pavement markings in September of 2008 under the direction of Dan Betts, Region Two Pavement Marking Supervisor. The markings were evaluated fourteen months later. Only minor chipping was found on the edges of the markings on the initial evaluation. Since northern Utah experiences several snow storms a year, pavement markings are subject to being scraped by plow blades. The first shields are still holding up well after several snow seasons.
The shield pavement markings will continue to be used where needed.