Soy-Based Tech Revamps 24 Miles of Iowa Roads

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Iowa State University engineers have developed a soy-based pavement technology that was used to rehabilitate 24 miles of rural roads in northeast Iowa's Clayton and Fayette counties and the town of Volga. The "soy roads" project used 12,000 to 15,000 bushels of soybeans and eliminated the need for 40,000 barrels of crude oil in the paving process.

Why it matters

This soy-based pavement technology provides a more sustainable and environmentally-friendly alternative to traditional petroleum-based asphalt for road construction and repair. It helps reduce reliance on fossil fuels while supporting Iowa's agricultural economy by utilizing soybeans grown in the state.

The details

The 24-mile demonstration project used soybean-based paving products developed by Iowa State University engineers Eric Cochran, Christopher Williams, and their research groups. Their startup company, SoyLei Innovative Products, now produces the technology. The paving process involved ripping up the top 4 inches of existing asphalt, grinding it, and mixing it with a soy-based emulsifier to create a new base layer. This was then topped with a layer of hot-mix asphalt also containing a soy-based binder.

• The 24-mile soy roads project was completed in the summer of 2026.
• The paving work on the 8.6-mile C14 county road south of West Union took place last summer.

What’s next

The success of this 24-mile demonstration project is expected to lead to further adoption of the soy-based pavement technology for road construction and repair across Iowa and potentially other Midwest states.