A slick road surface caused by the wrong asphalt mix on the stretch of Interstate 40 between Parks and Bellemont will require the freeway to have a reduced speed limit until further notice, Arizona Department of Transportation officials said.
The speed limit, which is usually 75 mph, will be reduced to 55 mph until the department determines it is safe to raise it again.
The department’s public information office released a statement that said the asphalt that was laid during the pavement replacement and preservation project was “more permeable than typical asphalt mixes.”
“ADOT crews plan to check the surface condition next week and take appropriate action before shutting down (the) project for the winter,” ADOT officials said. “Construction crews will come back next spring when temperatures warm up and complete the project by laying a final layer of asphalt, known as friction course, through the project area.”
Residents of the communities west of Flagstaff worry about what the more permeable surface will mean for safety.
“If it’s not going to wick the moisture away and will keep it on the road, to me that sounds like black ice and that’s the worst thing that could happen,” said Andrea Thoeny, a resident of Bellemont.
Officials from the department said there is not a “typical” mix, but said crews determined that the asphalt that has been placed would work best if it is fog-sealed until another layer can be placed in the spring.
The cost for the project is $13.9 million, including $105,424 for the asphalt-rubber seal that was placed before the winter shutdown, officials said.
“Crews have since used an asphalt-rubber product to seal the 12-mile stretch of I-40 in both directions in order to help the road resist moisture from rain and snow,” the statement said.
After the asphalt-rubber product, called fog seal, was applied, ADOT crews determined the eastern portion of the project, between Bellemont and A-1 Mountain, was in good enough condition to raise the speed limit back to 75 mph. The portion between Parks and Bellemont, however, is “such that it’s safer to keep the speed limit to 55 mph for the time being,” according to the statement.
Officials said the speed limit difference is due to friction levels on the surface on the two stretches of freeway.
“After a fog seal, traffic and grit improve friction by roughing up the surface. That’s happened enough on six miles to raise the limit back to 75 mph,” ADOT officials said in a statement. “We’re continuing to test the surface on the remaining six miles to determine whether the friction level has reached the point that we can raise the limit from 55 mph.”
Residents of the area worry about what the freeway will be like once ice and snow make the road even slicker.
“I think we are definitely very concerned,” Thoeny said. “It seems like they don’t really care.”