Home to some of the top-rated city park systems in the country, Minnesota holds a high bar for well-maintained trails — and that doesn’t happen by accident. Paved trails require planning, inspection, maintenance, and long-term investment to remain safe, accessible, and enjoyable for the communities that use them. At this year’s City Engineers Association of Minnesota Annual Conference, a breakout session on trail pavement management reviewed practical approaches for agencies looking to better maintain and extend the life of their trail infrastructure.
Pavement condition ratings
Agencies are turning towards numerical pavement ratings to frequently assess the level of maintenance needed. Primarily located in suburban Hennepin County, Three Rivers Park District encompasses 25 parks and park reserves, 27,000 acres of land, and a trail system spanning hundreds of miles. To establish a preventive maintenance program, the agency uses a visual Pavement Surface Evaluation and Rating (PASER) system developed at the University of Wisconsin–Madison. Every two years, the system assigns all trail pavement a score from 1 to 10. “Our goal is to have a PASER of 6 or higher … We noticed that anything below a 4 is when you start getting negative feedback,” said Josh Bowe, senior manager of engineering at Three Rivers Park District. This system helps the agency determine which areas need routine repairs or full reconstruction.
Taking a different approach, the City of Maple Grove worked with Cyvl, an infrastructure intelligence platform, to complete artificial intelligence (AI) trail pavement ratings in 2024. R.J. Kakach, Maple Grove city engineer, noted that retaining a human element was crucial to this process. “I reference art versus science,” he said, “science being the number that it spits out, and art being getting out there and looking at it … and really making sure the number fits what you’re seeing in the field.”
Preventive maintenance
Preventive maintenance is just as important as reactive maintenance to the overall lifespan of a trail. “If you construct a trail and don’t touch it, we anticipate you’re going to get a 20-year life out of [it],” Bowe explained. “Our goal is to extend that, to get 30 years out of the trail pavement life.”
Three Rivers Park District completes prerepair projects and microsurfacing at 7, 14, and 21 years after a trail was constructed to correct settlement and root damage, seal cracks, and fix other issues affecting pavement quality. In conjunction with PASER ratings, routine repairs are also made between these benchmark years. While preventive maintenance efforts can be expensive, they are investments that can significantly extend trail life and save agencies money down the road.
While the City of Maple Grove prioritized full reconstruction projects in the past, it’s now taking a similar approach to that of Three Rivers Park District, Kakach explained—shifting funding towards preventive maintenance, like crack sealing and microsurfacing, while pavements are within 75 percent of their lifespan.
Instead of doing full reconstructions when larger repairs are needed, the agency plans to replace trail pavements in sections — cutting out only what needs to be fixed and keeping the salvageable segments in place. “We want to have long-lasting, cost-effective trails,” Kakach said, noting that the city’s goal is to use the right treatments at the right time.
