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The science of roads
Published 11:11am Monday, July 9, 2012What’s the PCI?
It’s a question the city of Fergus Falls will soon have answered. Earlier in the summer, the city council voted to contract with GoodPointe Technology to do a “drive analysis” of the city’s roads. GoodPointe will put the information it finds into a program linked to the city’s Geographic Information Systems data, which will help the company come up with the pavement condition index for each of the city’s roads. The PCI of a road is an important factor in the city’s decisions regarding which roads need to be repaired or replaced.
Describing the PCI information as “just a tool in our toolbox,” Public Works Director Anne Martens explained how the drive analysis works.
“We started this in 2006 and 2007,” she said, adding that GoodPointe recommends another drive analysis every five years to keep information up to date. “They went and basically surveyed all of our roads in the sense of their quality.”
Essentially, GoodPointe compiled information about “distresses” to each road in town – from potholes to ruts to cracks to the dreaded “alligatoring,” in which several smaller cracks in one area indicates a road failure susceptible to potholes and water damage. GoodPointe uses that information to come up with a PCI, which can range from the absolute worst score of 0 to the pristine 100.
In a rural Minnesota town that sees its fair share of traffic and weather deterioration, road replacements and repairs must be prioritized. Though many other factors also go into when to put money into a road project, Martens said there is a PCI guideline the city likes to hit.
“We strive for 70s,” she said.
That was a goal hit more often than not when the city got its PCI results in 2007. At that time, 77 percent of the city’s roads were rated at a PCI of 70 or higher, with only 2 percent of the roads rated at below a PCI of 50.
The city has limited resources for road repair, resulting sometimes in what Martens called a “catch-up game.” With road maintenance funds typically budgeted at $190,000, patch-ups and similar repairs are done on roads that have deteriorated down to the 50s, increasing their PCIs and lengthening the life of the roads. It’s usually not cost-effective for the city to repair roads with sub-50 PCIs, but since there is a limited amount of funds available for road reconstruction, the city usually won’t completely rebuild a road until its PCI drops below 25 or if major repairs to the underground utilities are needed.
This year, for example, the city is rebuilding several stretches of road in the area of Mill Street near Lake Region Hospital, as well as parts of Vasa Avenue and Arlington Street. In the former case, the minimum amount of maintenance funding has been put into the Mill Street area in the last few years because the reconstruction plan has been in the works. In the latter case, reconstruction was moved up after major utility problems under Vasa and Arlington needed a more permanent solution.
Though those projects are the only reconstructions scheduled this year, mill and overlay projects are scheduled for Cedar Avenue between Cleveland Avenue and Northern Avenue, Northern between Beech Avenue and Friberg Avenue, Beech from Northern to Friberg and Spruce Street from Broadway to Vine Street.
“They are lower PCIs, (but) the utilities aren’t bad,” said Martens, explaining why those roads won’t get full-blown reconstruction.
When the city does road work, it inputs more information into its PCI program, known as ICON. Though ICON uses the new information to adjust the PCIs of roads up or down, GoodPointe recommends drive analyses every five years because they come up with more accurate figures – figures that the city can base its next several years of road work on.
“It’s like an audit of our system,” said Martens.
Though she said the analysis later this summer will come up with more specific numbers, Martens estimated that the city road with the highest PCI is the southern part of Lakeside Drive, which was reconstructed last year, probably followed by the recently overlaid Friberg Avenue. A road reconstruction resets the PCI at 100. Besides the roads getting repaired this year, other city roads with low PCIs include Junius Avenue from Union Avenue to Cascade Street and several roads in the area of Summit, Highland and East Mt. Faith avenues. Work is planned in those areas in coming years.
In addition to PCIs, funding sources and utility repairs, the city also relies on resident feedback when it comes to road work – especially when fixing potholes, which the city tries to do as soon as possible, Martens said. She knows road conditions can be frustrating at times, but she said the city does what it can.
