DOT’s Resurfacing Priorities Set By Detailed Road-Scoring System

Tue April 26, 2005 - Southeast Edition
Jim Ross

Like all states, Alabama has a resurfacing (asphalt) program to keep its roads in good shape. But how does the program work? And how does Alabama stack up when compared with the programs administered in other Southeastern states?

The Process

First, some details of how the process works here.

Since 1983, Alabama’s Department of Transportation (ALDOT) has had a pavement management system that rates flexible pavements. The program’s philosophy acknowledges the reality of roads: You have to do the right amount of resurfacing work at the right time.

“If we wait too long to resurface a roadway, the costs escalate rapidly. If we resurface too soon, we are not getting the full life out of the roadway,” department officials wrote in a presentation about the resurfacing program.

Experts examine roads for rutting, cracking, rattling, and so on, then feed the information into an algorithm that assigns each road segment a score of zero (worst) to 100 (best). Once the numbers are in hand, the next stage begins.

“Any pavement section with a score of 55 or below is a candidate for inclusion in the resurfacing program,” the presentation said. “Any section with a score between 55 and 70 can be considered due to extenuating circumstances. Any section with a score above 70 requires strong recommendation from the respective division engineer and extensive review by the maintenance engineer, and the materials and tests engineer.”

Then begins the prioritizing. The listings are reviewed at the division level, where engineers examine the roadways in their area and provide input into the selection of candidate projects. Based on that input, the division engineer submits his or her recommendations for resurfacing projects.

“The Maintenance Bureau reviews the recommendations from the nine divisions, obtains approval from the director and then provides the approved lists to the divisions and the Bureau of Materials and Tests,” the presentation said.

The next step: The bureau coordinates with the divisions and districts to schedule what is known as “Falling Weight Deflectometer” testing, which indicates the existing structural capacity of the roadway.

“The division obtains cores of the roadway to determine asphalt thickness and layer conditions,” the presentation said. “The division also requests traffic volumes from the Transportation Planning Bureau. This data is also provided to the Bureau of Materials and Tests.”

Once the priorities are set, the department conducts a study to determine how much overlay is required. The department uses the AASHTO Design Guide to determine how much capacity is required to provide the desired service life.

“We design for an eight-year time period between overlays,” the presentation says. “This seems to be a good target, as any more frequently and we spend too much time with the road under maintenance, any longer and we are putting too much money up front for some future value. This gets back to good economics and engineering practice.”

After all the documentation has been assembled, the information is sent to the Construction Bureau and the Maintenance Bureau for further processing. From there the plans are drawn, the contract is let, the project is built, accepted and turned over to the Maintenance Bureau.

(As for materials: For projects that have light to moderate traffic, Superpave mixes are used; for moderate to heavy, Superpave mixes with polymerized asphalt are used; for heavily traveled roadways, such as interstates, a stone matrix asphalt is used.)

A Comparison

As for financing, it’s difficult to compare exactly what individual states spend on resurfacing programs, since states might have different ways of accounting for money or different aspects in their programs. But here’s a general look:

• In Alabama, the state spent $100.06 million in fiscal 2002 on resurfacing roads (excluding bridges and interstates.) Approximately 668 mi. were resurfaced. In 2003, the figure dipped slightly to $100.05 million. In that year, 531 mi. were resurfaced, according to Ron Newsome, assistant state maintenance engineer, roadway, in DOT’s Maintenance Bureau.

• In Louisiana, the Department of Transportation and Development spent $204 million on pavement overlays and road and bridge preservation during the fiscal year that ended in June 2003, the latest period for which full statistics were available as of this writing. The department completed pavement preservation on 347.5 mi. of roadway that year.

• In Mississippi, for the fiscal year that ended in June 2003, the Department of Transportation spent $126.1 million on its maintenance program. With that money, the agency reshaped 5,741 mi. of non-paved shoulders, applied 4,313 mi. of pavement striping, sealed 596 mi. of highway and resurfaced 556 mi. of highway, according to the agency’s annual report. This resurfacing, the report said, ensures “a smoother, safer ride for motorists, and [extends] the life of the roadway while delaying costly reconstruction. By investing in preventative maintenance to resurface highways at the appropriate time during their life cycle, valuable highway money is being stretched even further.”

• In Florida, during 2002-03, the state resurfacing program improved 2,720 lane mi. (including interstate, turnpike, arterials and freeways and off-system roads) at a cost of $453.7 million. The program “provides for pavement resurfacing, rehabilitation, minor reconstruction and pavement milling and recycling,” according to the state Department of Transportation.

Bob Burleson, the president of the Florida Transportation Builders Association, said the state has a strict system for resurfacing, and that it has been pursued “pretty aggressively” by the Department of Transportation.

• Tennessee spent approximately $80 million on the state resurfacing program, plus $35 million a year on interstate resurfacing, in the most recent year. On the state side, in the past two years, $65 million has been taken out of the road fund and shifted to the general fund, said Kent Starwalt, executive vice president of the Tennessee Road Builders Association. In the first year, the big hit came out of resurfacing funds. “They have made a concerted effort this past year to get it up to $85 million,” Starwalt said.

How Does AL Measure Up?

Does Alabama do enough? Newsome, from DOT, said the state could always use more money for this purpose.

“In order to function effectively, we need approximately $250 to $300 million each year for improvements and maintenance of our highways,” he said. “For the past three years, the resurfacing program has averaged 585 miles of resurfacing on an average budget of approximately $98 million.”

Mel Monk, executive director of the Alabama Asphalt Pavement Association, noted that the state is consistently ranked in the 10 to 15 states nationwide in terms of quality/condition of roads.

“For the amount of money spent compared with other states, I think that’s really good,” he said. “I think a lot of that speaks to the quality of engineers at the DOT.”

(Reprinted with permission from “The Alabama Roadbuilder” magazine, fall 2004.)