Nearly 10,000 years ago, with little else to occupy their time, the first humans wore natural pathways into the dirt while hunting for food and water. As populations grew, they saw the need to create more formal roadway systems to transport goods between villages. But these roads often washed away entirely in heavy rain, and early humans hated that. By 4,000 B.C., humans had developed new methods for making roadways more resilient, and the world's first paved roadways soon emerged in the Indian subcontinent and the Middle East.

It wasn’t until 312 B.C. that the Romans recognized the political advantage that reliable roadway systems could provide in building their empire.

“Hey,” one particularly forward-thinking Roman said to another (Romans were surprisingly informal in their interactions).

“These paved roads are cool and all, but if we don’t improve upon the design, they won’t last very long. Since we want to be the biggest and best empire there is, we need to spend more time making them resilient now or else we’ll end up wasting our future empire-ruling years rebuilding them over and over. And that’s going to be expensive and inefficient.”

So that’s what they did. They laid foundations of crushed stones under new roadways to make them stronger and less susceptible to flooding. More than 2,000 years later, tourists still marvel at these enduring roadways – all because the Romans saw the importance of incorporating different materials and methods into roadway construction to make them last longer than ever before.

Over time, we improved upon these fundamental roadway construction techniques. By the early 19th century, a Scottish engineer implemented a process to top multi-layer roadbeds with soil and crushed stone aggregate and then pack it all together with the use of heavy roller machinery and later, tar. With the subsequent invention of bicycles and motor vehicles, roadway construction gained new significance. Teams of men with picks and shovels began carving out modern roadways across the world. Soon they were replaced by large machinery that improved upon their methods by quickly grinding up existing pavement to use it as aggregate beneath layers of asphalt on new roads. The process continued to evolve as generations of engineers kept thinking like the Romans – these roads are great, but how can we make them better?

Modern legislature prioritized roadway development over sustainability

Millenia later, the world saw more advancements in roadway construction processes and technologies in the last 135 years than ever before. Dominated by conflict, the 20th century brought an increased need to efficiently move military resources across great distances. Just like the Romans, modern civil engineers built long stretches of highways to aid in war efforts. The resulting interstate systems revolutionized civilian travel and underscored the political and economic advantages of resilient roadways. With advancements in construction processes and the proliferation of automobiles, America raced to build roadways that met traffic demands as quickly as possible through the Great Depression and both World Wars.

In 1944, under the leadership of President Roosevelt, the country established the Federal-Aid Highway Act. By 1952, the country identified the genesis of the Interstate System, which along with other major highways, would eventually span 1.2 million miles. With funding approved by multiple administrations, construction of these highway projects continued for the next 40 years.

Subsequent administrations prioritized the development of America’s transportation network – but didn’t specify any requirements for their long-term performance:

• Eisenhower established the Highway Trust Fund in 1956 to set uniform design standards for the Interstate System
• Kennedy’s Federal-Aid Highway Act of 1962 set the foundation for modern transportation planning
• Johnson’s Highway Beautification Act of 1965 controlled outdoor advertising, and his National Traffic and Motor Vehicle Safety Act of 1966 set highway safety standards

Nixon’s National Environmental Policy Act of 1970 ushered in a new focus on environmental sustainability in construction projects, and the iconic Keep America Beautiful “Crying Indian” ad of 1971 left an enduring legacy of environmental idealism. This new interest in environmental protection could have marked a significant moment in history when America embraced sustainability in roadway construction – but it didn’t. Subsequent administrations threw more federal money at highway and bridge repairs and safety improvements, but none of them established targets to build new roads to last longer and require less upkeep. With this myopic view of transportation planning, America set the tone for decades of roadway construction initiatives that prioritized construction speed over long-term roadway resiliency. Collectively they told us, “let’s build our highways as quickly as possible now and let someone else worry about fixing them down the road” (early administrations were notoriously punny), and we never veered from the outdated approach.

America entered the 21^st century with more paved roads than ever before – and a new responsibility to keep them in good condition. With incredible advancements in technology that can prolong the lifetime of roads, we have the tools to build roads to last longer and impress future civilizations with our engineering achievements, but we’re not consistently using them. So when tourists in the year 4,020 hop out of their spaceships and check out our ancient roadway system, what will be left for them to see?

The case for building better roads now

The latest Infrastructure Report Card rates America’s roadway infrastructure as D+ – meaning it’s in poor condition and below standard, with many assets exhibiting significant deterioration and approaching the end of their service life.

This assessment isn’t an exaggeration; the condition and capacity of America’s roadways are “of serious concern with strong risk of failure.” Specific roadway assets rated as “low fair” are cracked and “unfit for high-speed travel,” while others are “poor” with excessive bumps and potholes that create “uncomfortable rides.” The congestion and accidents caused by these deteriorating road conditions cost the country nearly $120 billion annually and contribute to 38,000 highway fatalities each year. Failing infrastructure is also responsible for a staggering 6.9 billion hours wasted in traffic – that’s 42 hours of wasted time per traveler each year.

It’s not surprising given the demands on roadways. In 1958, there were 68 million vehicles on the road; in 2020 that number exceeds 253 million. Today, roadways enable 90% of American travel and the delivery of 75% of all consumer goods. Often, the crushing traffic volume from American travelers and giant 18-wheelers exceeds roadway capacity by three to four times their design weights. Despite the quadrupled traffic volume, American lane-miles of pavement have grown less than 20% in the last 60 years. With costs to construct and repair transportation infrastructure exceeding $150 billion each year and consistent funding shortfalls, we simply cannot repair aging infrastructure fast enough to keep up with increasing traffic demands.

At the current state, the country’s roads are rated 16th in quality compared to other nations – a steep drop from the 2008 eighth place ranking. Despite $28 billion spent each year on roadway maintenance, America’s roads cannot match the quality and resiliency of comparable infrastructure in other countries. In Europe, highways actually carry more traffic and heavier truck weights than U.S. roads, but they offer smoother rides and increased durability. European highways are also designed to last 40 years – double the lifetime of their American counterparts.

To remain competitive in the global economy, the United States needs a world-class, safe and efficient transportation system, and we need to take steps now to ensure its resilience in the face of increasing traffic demands. We can’t raise our grade from D+ to an A by putting bandages on old roadways and expecting them to perform better with increasing traffic volumes.

With the help of engineers specifying innovative technologies and DOTs setting clear goals for pavement performance outcomes, we can achieve A+ infrastructure that lasts for centuries to come.