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St. Paul fields at least a dozen three-person crews when they’re not diverted to plowing snow and salting at least some roads during the late snowfalls.
Hennepin County has three dedicated patching trucks that keep asphalt warmer and more pliable because the bed is enclosed, unlike dump trucks the county also sends out with patching mix. There’s also another unit that can spray a mix of asphalt emulsion and rock into smaller potholes.
“It’s set up within minutes,” McLarty said.
Parkway: A ‘frightmare’
Meanwhile, back on West River Parkway, help for heavily patched and potholed sections has been a while coming, despite a program of joint funding by the Park Board and the city. This year’s section was held back from repaving projects last year immediately north and south of it. That’s because of metro storm tunnel construction at 4th Street, plus university concerns about accessibility during other construction. But some drivers notice the results.
“It was a frightmare,” said Jeff Spartz of Eagan, who drove the section recently. “No one was going over the speed limit, I can assure you of that.”
The parkway paving program sometimes needs to mill down only 2 inches of spalling pavement in order to lay fresh blacktop. But for this parkway, workers will mill down a full 7 inches, which may take them into virgin soil.
That’s based on what Kennedy said crews have found in other parkway locations. The parkways, built in the 1970s, were supposed to have 7 inches of paving over a gravel base. But often that’s not what crews are finding. Good road building practice lays paving atop a thick base of gravel so that roadway subsurfaces can drain. That keeps the freeze-thaw cycle from heaving pavement. It’s particularly surprising that such a base is absent given that some sections of parkway run on unstable peaty soils near lakes or swamps.
Spartz was on the Park Board when the current parkways were built but said he was surprised to hear of the skimping on base, a decision that he said sacrifices the long-term durability of a roadway. But motorists will see a better surface soon.
“They’ll love it when it’s done,” Kennedy said.
Steve Brandt • 612-673-4438