The scene may not have looked extraordinary, but in the annals of Seattle street maintenance it was, perhaps, a notable event. As the sun beat down on the blacktop at Rainier Avenue South and South Charles Street on Monday afternoon, a worker pushing a sprayer that was a bit bulkier than a shopping cart laid down fresh, white crosswalk lines.
What made the 8-inch-wide stripes unique was not their location or configuration, but the material coming out of the sprayer's nozzle. The Seattle Department of Transportation typically uses latex paint for striping street lanes, and more resilient "thermoplastic" to mark crosswalks. The material in the sprayer was Methyl Methacrylate, or MMA, an ultra-tough, high-priced road paint. The three crosswalks at the T-shaped intersection were the first ones the city has striped with the substance.
"The material is very expensive, but it lasts a long time," said the city's traffic engineer, Dongho Chang, as he stood on the street corner, watching two SDOT employees wearing coveralls, reflective vests and respirator masks mark one of the crosswalks. This year, SDOT made plans to test MMA on the crosswalks at the intersection striped on Monday and at another location in the city's downtown core. If the material holds up, and the costs pencil out, then the agency might look to use it more widely for painting crosswalks in the future.
Two members of an SDOT striping crew mark a crosswalk on South Charles Street, at the intersection of Rainier Avenue South. Photo: Bill Lucia
Crosswalk restriping is one component in the city's ongoing battle to maintain and repair Seattle's 1,677 linear miles of streets. The three crosswalks at the intersection on Rainier are among 560 that SDOT plans to mark this year using funds from the Bridging the Gap levy. Voters approved the property tax measure in 2006 to provide $365 million for roadwork.
SDOT committed to re-marking 5,000 crosswalks during the levy's nine-year term, which expires at the end of 2015. If the agency meets its 2014 goal, then by year's end SDOT crews will have restriped 5,289 since the levy went into effect.
Currently, SDOT has rated the quality of 5,253 city crosswalks. As of Tuesday, 3,122 were in good condition, 689 were fair and 1,442 were rated poor.
Not fade away: A crosswalk on Northeast 80th Street, near Lake City Way, shows its age. Photo: Bill Lucia
"I would say that restriping of crosswalks is one of the most frequent requests I receive," said City Councilmember Tom Rasmussen, who chairs the Transportation Committee. "There is probably a list of 5,000 other crosswalks from the public that we haven't painted yet," he added. "There are a lot of needs we have to meet."
Despite those frequent requests and the fact that 27 percent of the pedestrian pathways SDOT has rated are considered poor by the agency's own standards, Chang challenged the suggestion that the city's crosswalk markings were in rough shape overall, and said he was proud of the agency's restriping efforts. "We're making our crosswalks visible," he said.
The thermoplastic material the city commonly uses for crosswalk stripes tends to wear out in four to six years. In locations with heavy traffic and concrete pavement, Chang said it can fade away in just one year. Some crosswalks SDOT put down in the early days of Bridging the Gap may have already been erased by car, truck and bus tires.
By comparison, striping done with MMA can last up to 10 years, according to Chang. The downside of the product is the cost, which can be eight to 10-times as much as latex paint.
Chang could not provide an immediate dollar estimate for how much the crosswalks at Rainier and Charles would cost. But a 2010 Federal Highway Administration report to Congress stated that the price per foot for an MMA similar to the one SDOT was applying could be between $0.80 and $1.65 for a 4-inch-wide stripe. Comparable thermoplastic would cost as little as $0.47 to $0.58 per foot, based on the figures in the report.
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