Evaluating the Effects of Modern Agricultural Vehicles on Rural Roads

Abstract: Rural roads are facing increasing deterioration due to the growing use of modern, heavier farm machinery, which is far heavier than the original design based on the anticipated weight when these rural roads were built. Machines like John Deere's 9RX tractor, which can weigh up to 84,000 pounds, exert heavy stress on rural roads, especially during vulnerable periods like the freeze-thaw cycle going through the seasons. The result is extensive cracking, rutting, and shoulder damage. Cracks and shoulder damage allow water to pool and penetrate road surfaces, leading to deeper structural damage. Currently, local agencies are taking preventive strategies, which include incorporating crack-filling, millings, making thicker pavements using recycled asphalt, wider lanes, and improved drainage to handle larger loads. While preventive measures are cost-effective, they are insufficient, requiring consistent repair strategies. Adding additional millings to the shoulder for support is an economical short-term solution, but it needs to be freshened yearly for it to be effective. This research surveyed several rural roads and recorded current best practices for accommodating heavy agricultural vehicles. A numerical analysis is done to understand the impact of heavy loads on the existing roads, and several scenarios, such as existing pavement structure, full-depth HMA, HMA-PCC, and PCC-PCC composite pavements, are explored. Each scenario's stress, strain, and deformation estimated under heavy loads are compared. The study will help rethink the design and maintenance practices of rural roads. The mid-west states' rural roads must accommodate the heavy agricultural vehicles since they are the nation's leading corn and soybean producers. Our role in implementing the findings of this research is crucial in ensuring the sustainability and resilience of our rural road infrastructure.