Asphalt is the most common substance used in street paving because it is waterproof, relatively cheap, easy to use and maintain and lasts a reasonable length of time. It is a petroleum derivative and contains bitumen which is dark brown or black and includes tar and other viscous substances that come from coal. This allows it to bind well with stone and sand which are the aggregates used to surface streets. Asphalt's first recorded use was in Babylon during the reign of King Naboppolassar in 625 B.C.
Concrete is seldom used in street paving anymore but in 1915 when automobiles began to replace the horse and buggy, street paving became a necessity. In fact, the California State Legislature passed a bill known as the "Get Out of the Mud Act" to encourage people to modernize the streets. The Granite Rock Company was one of the first to pave streets with its patented graniterock and proceeded to pave most of the streets of Santa Cruz and Salinas with this form of concrete.
Many cities are now using recycled materials to pave their streets. According to a report by the Rural Conservation Alliance, nine out of 31 cities that responded to a survey "used reclaimed asphalt pavement for base courses or for paving." Some of the recycled materials include tire rubber, which is used as a binder in asphalt. According to the same report, Arizona, California and Texas use 18 percent of rubber in hot asphalt which translates into using over 2,000 tires per lane for each mile of the street that is paved with this recycled material.
Cobblestone was the usual choice of street paving in most European countries and a few old North American cities have cobblestone streets that still exist today. The word cobblestones comes from old English and means "large lumps," which accurately depicts the look of a cobblestone street. Cobblestones were used over dirt roads to keep down the dust and provide a stable surface for animals, carts and people. They were durable, easy to acquire from riverbanks and free to all.