Interstate 540's Previous Life: DOT Recycles with Roadways

Traffic engineers say I-540 will relieve clogged connector roads, create another route to the Research Triangle Park and eventually form a complete outer loop around Wake County.

The partially built highway is now serving another purpose. The DOT has turned the new road into one big recycling bin.

Under the guidance of the DOT's Value Management Division, crews are putting things into the road that otherwise would have ended up in the landfill.

Asphalt shingles thrown out by builders have been melted down and mixed into the pavement. Plastic, including recycled soft-drink bottles, has been melted and compressed into fence posts. The posts will last 40 years, instead of the 15-year average life span for wood posts.

The state is also using treated sewage sludge to fertilize roadside slopes.

"It's heated to 2,000 degrees to kill all bacteria and whatever might be in it," says DOT engineer Frank Draper. "It's been run through all types of systems, and it's nothing but plain old, good old fertilizer."

Raleigh donated the sludge. The savings to the taxpayer over buying commercial fertilizer: $15,000.

DOT engineers say the next section of the Outer Loop from Leesville Road to Highway 50 will be open to traffic by Christmas.