From ancient mud bricks to salty beet juice, roads have a long, winding history—and a glowing future.
Long-wandering human tribes finally hunker down in 9000 BCE and form villages. To hop between settlements, they convert game trails—like the 440-mile Natchez Trace trail between Mississippi and Tennessee—into walking paths.
Around 5000 BCE, oxen become the preferred draft animal and the travois—a V-shaped frame that shoulders heavy weights—becomes the world’s first vehicle. Trackways widen to accommodate bigger loads.
Sumerians invent the best thing to come before sliced bread—the wheel—around 4000 BCE. Roads made of mud brick appear in the Indus Valley, while Mesopotamians build stone streets near Ur, Iraq.
Around 3300 BCE, log trackways are built in London to help sleds glide along. Corduroy roads of timber appear near Glastonbury, England, to help people trudge over mushy marshland.
Metallurgy makes stone cutting easier and roads smoother around 2000 BCE. On the island of Crete, Minoans build a road of sandstone that’s cobbled together with mortar—a first!
Asphalt debuts in Babylon in 625 BCE when King Nabopolassar paves the street leading to his palace. It will take Europeans another 2000 years to catch up. (Asphalt was also used to embalm mummies!)
THE ORIGINAL TURNPIKE
The world’s first toll gate is installed on England’s Great North Road in 1656. (The gate was a new idea; the toll was not. Travelers on Iraq’s Babylon Road had to pay up as early as the seventh century BCE!)
FOOD ON THE ROAD
Special formulas like SafeLane, which contain brine and other de-icing chemicals, can prevent frost and black ice from forming. But beet juice and cheese brine effectively clear roads too—and they’re environmentally friendly. In fact, when temperatures dip, a vegetable slurry performs better than road salt!
In 2011, a 90-foot span crossing the River Tweed in Scotland was made of 100 percent recycled plastic, which means it can’t rust and will never need to be painted. Old plastic bags and bottles are working their way into pavement too. In Vancouver, a waxy goo of recycled plastic is used to make asphalt flow more smoothly.
To save money, highway streetlamps are often turned off late at night—which pretty much defeats their purpose. But in 2014, Dutch engineers found a new way to keep the roads lit: glow-in-the-dark lane lines. A 0.3-mile stretch of road near Oss, Netherlands, is now flanked with photoluminescent pathways.
In the U.S., more than 2.5 million miles of pavement absorb the sun’s rays—and we do diddly-squat with it. California-based Solar Roadways plans to harness that energy by lining roads with durable solar panels, which would bake under a plate of tough glass. The first prototype was unveiled last year, and the company claims the technology could exceed the nation’s energy needs four times over.
In Gumi, South Korea, electromagnetic cables planted in the asphalt charge the city’s electric buses while they’re on the go, eliminating the need to stop at a charging station.