To keep rural roads in running condition, farmers, custom forage operators and custom manure applicators should join forces with local government and industry.

So says Kevin Erb, conservation professional development and training coordinator for University of Wisconsin Extension. He recently studied the effects of large ag equipment on rural roads.

“A lot of the laws governing the movement of waste hauling and farm equipment on rural roadways were written when a Farmall M was the most common type of tractor being used on farms,” Erb says.

Although farm equipment has increased in size since then, laws haven’t changed, he adds. “We were seeing farmers and custom operators getting fined anywhere from $1,000 to $7,000 for operating over weight limits.

“We wanted to take a closer look to see if there actually was more damage with today’s larger, heavier equipment and what might be done about it,” he says.

The funded study, which ran from 2008 to 2011, was instigated through the Professional Nutrient Applicators Association of Wisconsin, of which Erb is an advisor.

Equipment from grain carts to manure-hauling machines was tested over various concrete and asphalt pavements to compare what would happen under differing load and weather conditions.

Based on research results, Erb has come up with these recommendations:

Keep equipment toward the center of roadways. His research conclusively shows that pavement edges are more susceptible to damage from heavy loads than other parts of the roadway.

Several townships in eastern Wisconsin have successfully addressed the issue by closing roads to two-way traffic during heavy hauling periods, he notes. While that requires a fair amount of coordination with town/county officials and neighbors using the roads, several custom operators and manure haulers involved reported a 20% increase in the number of loads they were moving per hour.

“Their drivers didn’t have to pull off to the side of the road when meeting other vehicles (including their own empties returning from the field),” explains Erb.

Redesign field driveways. When drivers of heavy equipment take shortcuts through ditches to enter fields rather than entering via field driveways, a fair amount of damage is done to asphalt pavement. One root cause of the problem, says Erb, is that standard driveway culverts are only 20’ long. That doesn’t give drivers enough room to pull into or out of driveways without turning wide and running on opposite shoulders.

Replacing these culverts with 60’ models would allow equipment operators to safely enter and leave fields without skirting pavement edges. Townships could also alleviate problems by installing paved shoulders at approaches to field driveways.

Avoid operating on roads at certain times of the day. “One of the things that surprised us the most in our research was that time of day can have a very big impact on asphalt damage,” says Erb. “If we were moving heavier loads in the morning, when it was cooler, we saw dramatically less damage than we saw in the afternoon.”

Keeping equipment off roads when frost is leaving the subgrade or when the subgrade is wet can also head off damage.

Encourage townships to make selective investments. One Wisconsin township opted to make drainage improvements on several roads prior to a major repair project, Erb relates. The end result: the pavement showed no damage for five years. Before that experiment, town officials reported, craters were developing in roads within two or three years of doing repairs.

In another township in the central part of the state, officials had curbs and gutters installed next to farmsteads on several rural roads. The effort kept the subgrade dry and reduced damage; it also kept drivers closer to the center of the roads.

“They had to spend some money up front,” says Erb. “But now they’ve established a track record they can use in making future decisions. Over the long run, they’re likely to save some money.”

Erb’s bottom line: “Agricultural interests need to take a proactive role on these issues. But to come up with long-term solutions, farmers, towns and counties and industry will all have to be involved.”