Building roads is hot, dirty, physically demanding work. But well-built roads are essential to our modern, highly mobile society. After the earthmovers and grading machines have prepared the roadbed, layers of sand, gravel, and crushed stone are often applied. A tamping equipment operator then guides a special machine that vibrates thousands of times a minute to pound the material into the ground. Next paving equipment operators pour concrete or asphalt, onto the roadbed (or parking lot or airport runway). For less heavily used roads, a surfacing equipment operator may spray hot tar on a tamped stone base. Small stone chips will then be added before the tar cools. Typically, these workers are trained on-the-job. The demand for new highways remains high, while at the same time, aging roads need frequent repairs. So, paving, surfacing, and tamping operators will continue to be needed to keep the nation moving in the years ahead.