Hundreds of new signs the Ohio Department of Transportation is erecting along Toledo-area freeways will pay for themselves within a few years because they don't need electric lights to be bright at night, department officials say.
The replacements for highway signs that identify freeway exits will use modern, highly reflective materials that are brightly illuminated by headlights, Chris Waterfield, the department's district traffic engineer in Bowling Green, explained last week.
Although some individual signs have been replaced because of construction projects or traffic damage, "this is the first time we've done it on a big scale" since the local freeway network's construction, which mostly occurred 40 to 50 years ago.
"A lot of the cost is in replacing the sign structures," Mr. Waterfield said. "A rule of thumb is 45 years for the life of a steel structure, and most of our system was built in the late 1960s."
In recent weeks, crews have been replacing overhead and side-mounted signs along I-75 in northern Wood County. Overall, the Bowling Green district office expects to replace 185 signs in Wood County, 170 in Lucas County, 63 in Ottawa County, and 50 in Henry County, plus lesser numbers in other northwest Ohio counties, at a total cost of $2.8 million.
But based on a department analysis, Mr. Waterfield said, at least that much will be saved in electricity within 2 1/2 to 3 years.
Although new signs recently erected along I-280 and I-475 use tubular supports to combat vandalism, the districtwide program uses traditional latticework structures that can handle larger signs, the traffic engineer said.
The new signs have an expected service life of 10 to 15 years, Mr. Waterfield said. They could be left up much longer, even for the 40 to 50 years that current signs have been standing, "but they wouldn't be visible at night" because their reflectivity will fade over time, he said.
Besides the state-of-the-art materials, the new signs employ a new lettering style, or font, called Clearview that the Federal Highway Administration recently approved after years of studies.
The new lettering features more space inside closed-loop letters like "a," "b," "d," "e," "g," "o," "p," and "q," which the research showed makes it easier to read from a distance, especially at night and particularly for older motorists whose eyes often have trouble with reflective glow from signs' lettering at night.
The Clearview font also features a distinctive hook at the base of lower-case "l," making it more distinct from the capital "I" than those two characters are in the United States' traditional -- but never official -- sign font, known as Highway Gothic.
"Clarity from an increased viewing distance is a lot better," Mr. Waterfield said.
Older signs will be left up only in areas where the transportation department has major reconstruction projects on its drawing boards, such as on I-75 between I-475 and I-280 in Toledo, the traffic engineer said.
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