For people who drove U.S. 54 northeast into Holts Summit late Friday afternoon, this warning is old news: The state Transportation Department warned Missourians Monday "to be aware that the heat can affect the surface of roadways," causing "pavement blow-ups."
That's what happened just south of the Center Street interchange Friday afternoon, when a nearly two-foot-wide section of pavement broke apart in both northbound lanes.
Drivers slowed from the 70 mph speed limit to about 10 mph, to get across the suddenly uneven surface, causing a several-miles-long traffic back-up.
One minor injury accident was reported because of the traffic tie-up.
Sally Oxenhandler, a MoDOT spokeswoman, said Monday that a Fulton-based maintenance crew said they had fixed four other blow-ups on U.S. 54 so far - "three between New Bloomfield and Center Street, and one closer to Fulton."
Beth Wright, MoDOT's state maintenance engineer, said in the department's news release that blow-ups occur when the road surface expands at a crack or joint where moisture has seeped in.
"The crack weakens the pavement and the heat causes the pavement to buckle and warp," she said.
MoDOT crews are monitoring state roads, saying they will make repairs as soon as they occur.
But motorists who encounter a blow-up can help, Wright said, by reporting the problem.
MoDOT's toll-free customer service center can be reached at 1-888-ASK-MODOT (275-6636).