The biggest pothole Russell Davenport has seen thus far this year measured roughly 4 feet square by 5 inches deep.
It wasn’t the worst axle-buster that the La Grange public works foreman has ever encountered, but, hey, the season’s still young.
“With the weather Chicago has and the salt we put down on the roads, that pavement just keeps popping up,” Davenport said after his crew spent Wednesday shoveling out a cold patch on busy Ogden Avenue.
Experts say Chicago area motorists have been lucky so far, pothole-wise. Since February arrived with one of the longest stretches of bitter cold in the region’s history, the freeze-thaw cycles that produce rim-benders have yet to completely kick in.
Just wait. With temperatures reaching the 50s this week, the snow is melting through cracks and fissures in roadways before freezing again at night. It’s a perfect recipe for pavement popping.
“Whenever you get freeze-thaw cycles, you can almost hear the pavement cracking,” said David Schulz, director of the Infrastructure Technology Institute at Northwestern University.
It’s basic physics, Schulz explained. Water collects under roadways, freezes and expands, weakening the pavement above. After the water dissipates, a void is left, and the roadway collapses under traffic.
“Expansion is an incredible force,” Schulz said. “It’s strong enough to break up concrete and asphalt.”
On roads around the city and suburbs, crews with trucks loaded with patching material are becoming a familiar sight.
Chicago keeps about 17 crews working daily, filling about 200,000 potholes a year, said Brian Steele, spokesman for the Chicago Department of Transportation. One crew works at night in high-traffic areas.
Residents are encouraged to report potholes by calling the city’s non-emergency number, 311, Steele said. CDOT uses those reports to track and map potholes via computer so crews can repair them efficiently.
“Instead of just having crews drive around, we can go to targeted locations and be more effective,” Steele said.
The CDOT crews might want to better target north Lake Shore Drive, according to Chicago resident Colin Howe, who said the city’s showpiece stretch of highway is extremely deteriorated.
Chunks of surface asphalt up to 10 feet wide are missing in spots both northbound and southbound on the drive at Irving Park Road and at Montrose and Lawrence Avenues, Howe said.
“You can see 3 or 4 inches straight down,” Howe said. “It’s like an archeological dig; you can see the old layers.”
Steele said that stretch of Lake Shore Drive tends to deteriorate quickly because of its age. The road is scheduled for reconstruction in the next few years, he said.
Meanwhile, he said, “I will definitely let our pothole crews know that’s an area we can give special attention to.”
