The fabled highway, U.S. Route 66, which stretched from Chicago, Illinois, to Santa Monica, California, revolutionized transportation and the relationship Americans had with their cars. Several segments of the original highway can still be found in Illinois. One such section of original pavement was sampled by the Illinois Department of Transportation in Macoupin County, where the old road intersects a new high-speed rail crossing. The pavement core can inform materials engineers about the historic concrete used in its construction and its present condition. It can also help guide preservation and restoration efforts of remaining segments of the historic roadway.
Completed between 1926 and 1928, this highway (one of the original highways in the nation’s new highway system) stretched 2,448 miles. The “Mother Road,” as it was known, has been romanticized in songs and on TV. Songwriter Bobby Troup was the first to urge the motoring public to “get your kicks on Route 66,” and the song has been covered more than a dozen times since, notably by Chuck Berry and the Rolling Stones. The Interstate Highway System has mostly taken the place of U.S. Route 66 today, and the road was officially decommissioned in 1985. For more information about Route 66 history, preservation efforts in Illinois, and to see photographs of remaining segments, download this PDF produced by the Illinois Historic Preservation Agency in 2012.
As you do more research, you may come across the term petrography. Petrographic analysis helps engineers evaluate the condition of the materials that make up a roadway. It can help determine if there are any issues caused by wear and tear. Has freezing and thawing degraded the concrete? Are there interactions with chemicals that have caused problems? How durable is the material? Are there any concerns about its strength? Core samples like this one can help engineers answer these questions.