Pavement analysis will help City of Lawton set street repair priorities

A pavement analysis that city leaders hope will help them set priorities for street repairs and replacement will be presented to the City Council today.

The good news: 57 percent of Lawton streets fall into the Fair to Very Good categories, with another 6 percent in the Excellent category. The bad news: 53 percent fall in the Fair, Marginal and Poor categories, with another 3 percent rated Very Poor.

The City Council hired Infrastructure Management Services (IMS) in January 2022 to analyze Lawton’s streets, with a goal of driving over a majority of the city’s arterials and residential streets to analyze their condition, via lasers and cameras. When an IMS crew began its work in late May 2022, workers were driving a special van that held two laser systems on specially mounted brackets, analyzing the pavement as the vehicle passed overhead.

Tom Goodyear, lead operator for the crew, said the laser analysis captures things that may not be visible to the naked eye, helping to predict trouble before it is visible on the surface. He said IMS’ system relies on lasers and cameras to make the analysis: photographs show what is on the surface; the lasers, what is underneath.

“Lasers record the depth and thickness of cracks. How many there are and how wide they are, the deterioration of the road,” Goodyear said.

It’s a modern use of technology that replaces what had been the City of Lawton’s tried and true method for decades: a “windshield” analysis that means driving every mile of street in the city and visually inspecting its condition. However, the end result is the same.

“By using the information, we can prioritize repairs or reconstruction projects that need it the most,” Public Works Director Larry Wolcott said, adding that in the past, streets often were repaired based on a high number of complaints.

Wolcott said the laser analysis is important because it would let staff know whether a section of road is suitable for mill and overlay (grinding off the top layer of asphalt, then replacing it with new asphalt) or whether the subgrade is in such poor condition, it won’t support the surface above (making overlay pointless). That’s why the contract specified looking at defects such as cracking, potholes, corner breaks, roughness and other indications of pavement wear. The work also included details on signs, traffic signals, ramps, curbs and gutters, markings and striping, and other “right of way assets.”

IMS collected the data into a management report that the City of Lawton can use to make predictions and set priorities.

Some of IMS’ findings: 6 percent of Lawton streets fall into the Excellent category in the PCI (pavement condition index), while another 3 percent are rated Very Poor. The average PCI on 504 miles of surveyed city streets is 57 (in the Fair category), while the national average is 65 (in the Good category).

The report indicated Lawton is not spending enough on street work. It said the current annual funding level of $17.4 million will result in a backlog of 31 percent after 5 years. The backlog now is 19 percent, when the national average is 9 percent.