Highways have existed in some form for over 2,300 years. The first major engineered road network began in 312 BCE when Rome started building the Via Appia, and the concept evolved through centuries of innovation until the modern limited-access highway emerged in the early 1900s. The word “highway” itself dates to Old English, where “heahweg” meant the main road between towns, with “high” used in the sense of “main” or “primary.”
Roman Roads Set the Template
The Via Appia, begun in 312 BCE, originally stretched 162 miles southeast from Rome to what is now Taranto, Italy, and was later extended to the Adriatic coast. It was the first of a network that would eventually radiate in every direction from the capital. By the early second century BCE, four additional major roads connected Rome to Genoa, the Adriatic coast, central Italy, and the southern region near Capua. In 145 BCE, the Romans pushed beyond Italy entirely with the Via Egnatia, which crossed into Greece and Asia Minor to link up with the ancient Persian Royal Road.
What made Roman roads remarkable was their engineering. They were built with solid foundations, cambered surfaces that shed rainwater to the sides, and concrete made from volcanic ash and lime. They were famously straight, prioritizing directness over following the natural terrain. Many of these roads survived for centuries, and the English term “high street” was used before the 1600s to describe Roman roads specifically.
Roads Fell Apart, Then Slowly Improved
After the Roman Empire collapsed, road-building in Europe largely stagnated for over a thousand years. It wasn’t until the early 1800s that a Scottish engineer named John Loudon McAdam developed a construction method that would transform travel. Working as a surveyor for the Bristol Turnpike Trust starting in 1801, McAdam figured out that roads didn’t need to be dug into the ground. Instead, he raised them above the surrounding terrain to promote water runoff and dug drainage ditches on each side. He layered large stones as a base, then topped them with smaller stones weighing no more than four ounces each. Under the weight of passing traffic, these loose stones packed tightly together into a stable, even surface.
“Macadamized” roads lasted longer, handled any vehicle size, and cost a fraction of what older techniques required. This approach spread rapidly and became the standard for road surfaces throughout the 19th century, laying the groundwork for the paved roads that would follow.
The First Highways Built for Cars
The shift from roads that happened to carry cars to roads designed specifically for them began in the early twentieth century. In Berlin, the AVUS (short for “Automobile Traffic and Training Road”) opened on September 24, 1921. It was a dedicated, controlled-access road built for motor vehicles, and it charged drivers ten Marks to use it. That stretch of road still exists today as part of a German federal highway.
Meanwhile, in the United States, the push for long-distance automobile roads was already underway. On July 1, 1913, a group of car enthusiasts and auto industry leaders formed the Lincoln Highway Association with the goal of building a continuous, improved, toll-free road from New York City to San Francisco. They announced the route on September 14, 1913: a 3,389-mile line that cut as straight a path as possible across the country.
Driving it was another matter entirely. A highly publicized trip along the route took 34 days and involved mud pits in Iowa, sand drifts in Nevada and Utah, overheating radiators, flooded roads, and cracked axles. The Lincoln Highway Association’s own 1916 road guide called the journey “something of a sporting proposition” and advised motorists to buy gasoline at every opportunity, wade through water before attempting to drive through it, and avoid drinking alkali water along the way. Firearms weren’t considered necessary, but full camping equipment was, especially west of Omaha.
The Pennsylvania Turnpike Changed Everything
The road that would become the blueprint for modern American highways broke ground on October 27, 1938. The Pennsylvania Turnpike’s first 160-mile section, running from Carlisle to Irwin, opened in 1940, and it introduced design features that no American road had combined before: four divided lanes, long entrance and exit ramps (1,200 feet for safe acceleration and deceleration), banked curves, toll booths, and service plazas. It had no speed limit at the time.
The design philosophy was consistency. As engineer Charles Noble explained in a 1940 issue of Civil Engineering, unlike existing highways where design standards changed every few miles depending on when each stretch was built, the turnpike maintained the same characteristics across its entire length. Every effort went toward giving drivers uniform, predictable conditions. The turnpike’s financial success and engineering innovations proved that this model worked, and it became the template for the 43,000 miles of interstate highway that would follow.
Eisenhower and the Interstate System
Two experiences shaped the highway system Americans drive on today. In 1919, a young Lieutenant Colonel named Dwight Eisenhower joined a military convoy attempting to cross the country. The trip was grueling and slow, exposing just how inadequate American roads were. Decades later, during World War II, General Eisenhower saw firsthand how Germany’s autobahn network allowed rapid, efficient travel across the country. The contrast stuck with him.
As president, Eisenhower pushed for a national highway network, arguing it was vital for both civilian travel and national defense. The Cold War context mattered: military planners believed that rapid evacuation of cities and movement of troops required modern, multi-lane highways. The result was the Federal-Aid Highway Act of 1956, which authorized the construction of a 40,000-mile interstate system. The initial cost estimate was $27 billion, spread over a ten-year construction program.
That system, now stretching over 48,000 miles, defines long-distance driving in the United States. Its design standards, from controlled access points to divided lanes to consistent signage, trace a direct line back through the Pennsylvania Turnpike, the German autobahn, and ultimately to the Roman engineers who first realized that a straight, well-drained, solidly built road could hold an empire together.