And the machinery needed to lay gravel and dirt and concrete is petroleum driven machinery.

FORBES: Peak Oil and ERoEI: Still Nonsense

So, for example, a 300-acre plant near Dallas takes Bridgeport's sand and gravel and turns it into concrete pipes as big as 12 feet in diameter.

FORBES: Magazine Article

The alternatives to asphalt roads are gravel roads, dirt roads, and concrete slab roads.

FORBES: Peak Oil and ERoEI: Still Nonsense

Although feet were designed to walk barefoot on Earth's natural surfaces (grass, sand or gravel), they were not prepared to endure the concrete, asphalt and steel that covers so many landscapes today, Thompson said.

CNN: Flip-flops present feet with a painful problem