SIOUX CITY | Crews are repairing a city walking and cycling trail along Perry Creek after fissures developed during recent high temperatures. The problem has presented safety issues.

“The cracks run the way you are riding so you have to be careful,” said Frank Brinkerhoff, president of Siouxland Cyclists, a group of bicycling enthusiasts.

Buckling has occurred all along the 3.2-mile Perry Creek Trail, from the Missouri River waterfront to Stone Park Boulevard, said city Field Services Manager Brian Fahrendholz.

"We've had some blow ups due to that heat," he said.

Workers made repairs over the past two weeks and returned Friday to refill cracks after a petroleum-based sealant sank down, leaving the trail uneven, he said. The trails are made of concrete about 6 inches thick.

Last month was the eighth-hottest July on record in Sioux City, according to the National Weather Service. The warmest day of the month, July 22, registered a temperature of 104 degrees.

Similar pavement issues have been reported in Chicago, St. Louis and Memphis. Parts of a Guthrie, Okla., bridge closed Friday after extreme heat caused pavement to buckle. On Wednesday, a Davenport, Iowa, street that had been recently resurfaced melted, creating a sinkhole.

In Sioux City, city officials work with Siouxland Cyclists and the Siouxland Trails Foundation to identify areas to patch or replace.

Parks Maintenance Field Supervisor Kelly Bach said workers in the fall replaced about 60 cracked panels on the Perry Creek Trail. More fixes are planned on the trail north of 28th Street, behind the Market Place Shopping Center, Bach said.

The city replaces the pavement as money becomes available. The City Council set aside $50,000 for improvements and repairs to the city's 22 miles of trails this year.

Bicyclist Johnathan Vodochodsky, of Sioux City, who uses the trail frequently, said the city should replace more panels instead of using the sealant, which isn’t effective. He also said that the city’s heavy machinery harms the trail.

"We need a permanent solution by replacing the panels," he said. "As a taxpayer, I look at this as an investment into the community."

Fahrendholz said the trail can support the machines.

DeSmidt said he’s happy that the city works hard to keep the trails maintained.

“I think we have a positive relationship with the city,” he said. “They do listen.”

The trail cost $5.2 million to construct. It opened in 2007 and was expanded last year.

The Associated Press contributed to this report.