Learn about how highways are designed and the geometry behind what makes them safe and efficient.

How the US built the Interstate Highway system

As late as World War II, it took a well-prepared motorist roughly 10 days to cross America from coast to coast in a car. That all changed when the nation undertook its biggest public infrastructure project in 1956, the National Interstate and Defense Highways Act, initiating a 36-year, $114B mission to lay 41,000 miles of roads across America. Watch a smart overview here.

A primer on reading the rock layers of roadcuts

Road construction often requires cutting through layers of rocks, coincidentally exposing millions of years of rock formation. This simple guide introduces basic rock types, what causes curves and folds, and the major rock formations in regions around the US.

Fascinating 3D animation shows how Romans built roads

Highly efficient engineering and materials production allowed Roman administrators to lay down nearly 50,000 miles of roads across the ancient empire. These roads were built so effectively that many are still around today. Watch this quick 3-minute video to see how they did it.

Engineering the Overseas Highway connecting the Florida Keys

A 113-mile series of bridges called the Overseas Highway connects Key West—the southernmost point of the United States—to mainland Florida. The route originally served as a railroad but has required regular reconstruction due to major storms. This video traces the history of the project in fascinating detail.

The 1956 Federal-Aid Highway Act spent $25B to build 41,000 miles of freeway

Sold to Congress as a national defense measure, the Interstate Highway Act committed the federal government to covering 90 cents of every dollar spent on a 41,000-mile freeway network, a subsidy that reshaped American cities and supercharged car dependency.

The internet explained at five levels of difficulty, from protocols to internet flattening

Resembling a roadway with traffic laws that all cars must follow, the internet is the hardware that connects a source to a destination, and these connections must follow specific software rules. Although data had to travel through about 10 networks to reach a destination in the past, data centers increasingly consolidate traffic, just as a highway does for cars, to improve data speeds.

Roman roads have lasted for millennia and were key to its military might

Known for their almost absurd straightness, Roman roads connected the empire's armies, messengers, and traders as imperial administrators sought to keep down rebellion and build up Roman wealth. Rome's highways were expertly engineered, well-patrolled, and easy to navigate.

Explore the National Highway Traffic Safety Administration's guide to automated cars

This page provides answers to questions on topics ranging from liability for crashes involving autonomous cars to the safety benefits of these cars. A timeline of the evolution of automated safety technologies is also provided.

The 52-mile marvel of engineering inside Glacier National Park

Glacier National Park is home to over one million acres of natural beauty, but it also includes 52 miles of a manmade miracle in Going-to-the-Sun Road, which takes drivers on a majestic tour through some of the park's most breathtaking views. This brief history and photo gallery allows you to gain an appreciation for the incredible engineering behind the road’s construction.

Future President Dwight D. Eisenhower's horrible experience on a cross-country road trip in 1919 helped inspire him to create the interstate highway system.

The odds of getting seriously injured on a US roller coaster are one in 15.5 million rides taken

Understanding the mechanics of a ride can help explain why they are so safe. Lift hills, launches, and breaks are each crucial components of coasters and are designed to possess numerous safety features in case of any dysfunction.

Hydroplaning occurs when a vehicle's tires lose traction on wet roads

Water depth must be over 0.1 inches, and vehicle speed must exceed 50 mph for hydroplaning to occur. Tire wear, size, and tread patterns affect the likelihood of hydroplaning, which is more common for all-wheel drive vehicles.

School buses are the safest vehicles on the road

Even without seat belts or airbags, the big yellow school bus transporting millions of students to school each day remains the safest vehicle on the road. A long history of tragic lessons led to today's highly tested school bus design, including the padded compartments created by school bus seats, multiple emergency exits, cross-view mirrors, and more.

The complex science of snow removal

Plowing snow seems simple, but its actually a technically complex task and requires significant logistics, patience, and funding. New York City's 19,000 miles of roads require days to plow at a cost of $12M per inch of fallen snow, and roughly 17 million tons of salt were applied to road surfaces across the US in a recent year. Dive into the details of snow removal with an in-depth and funny video.

Why train derailments happen, 101

In 2021 alone, there were over 1,000 reported derailments in the US—and no amount of maneuvering will reduce those numbers to zero. This 101 explains the causes of train derailments and how safety protocols look to limit them each year.

Amateur engineers built America’s first great infrastructure project

With no engineering schools in the US, the Erie Canal was designed and built by self-taught amateurs who improvised new methods and became known as the “Erie School of Engineering.”

Why high-speed rail hasn't worked in the US

High-speed rail connects cities across Europe and Asia, but American attempts have faced ballooning costs and delays. California's failed attempt to connect San Francisco and Los Angeles is the most prominent example of the dysfunction.

At the 100th birthday of Route 66, a look at what makes it distinctive

The iconic road from Chicago to Santa Monica was first laid out by Cyrus Avery, a member of the highway board, in the 1920s. Before the interstate system was created in the 1950s (rendering the route a tourist route), Route 66 became the site of major roadside attractions, food stops, and lore as early American drivers explored the countryside by highway. This visual-rich essay showcases its origins and how the route stands today.

The engineering underlying the electric grid and why it needs to be modernized

The system includes generators for producing electricity and millions of miles of transmission and distribution lines to transport the energy. The substantial increase in the number of electronic devices and electrical demand since the construction of much of the grid in the mid-1900s has strained infrastructure, requiring continuous upgrades and massive investments in new construction.

An architect ranks the best bridges in the world

Architext Ezra Groskin builds bridges and argues that the best bridges do more than allow traffic. They should, he believes, encourage human interaction and lingering to ultimately become a destination of their own. Explore ten stunning designs that connect communities, from New York to Switzerland.

The American Society of Civil Engineers' infrastructure report card gave the US a C in 2025, its highest grade since the project launched in 1998.

Why Water Towers Are Built This Way

Feds crack down on sassy highway signs

Digital signs warning drivers to make good decisions have taken on some sass in recent years. No more, says the Federal Highway Administration.

The hidden engineering of gas stations

Contemporary gas stations are the result of a century of engineering progress. In the early 1900s, only a few thousand cars drove around, and they used kerosene. As vehicles and cheaper gasoline became more popular, fire hazards grew, forcing the invention of fuel pumps, underground storage tanks, and the automatic shutoff valve—all engineering marvels.

44 states in the US have implemented ride safety laws

Rides are developed and tested for years before they host passengers. Maintenance teams perform various tests every day before opening coasters to the public. The chances of risk are rare, as exemplified in 2019 when amusement parks saw .8 injuries per million rides.

Explore the system of ancient Roman roads with this interactive

The Itiner-e map includes unpaved secondary roads that connected farms and towns to the empire's primary routes. Explore routes, view three-dimensional elevation, and compare the old roads to contemporary ones with this sprawling interactive project.

Avenues are typically wider than streets

Generally speaking, avenues are roads with buildings or trees on both sides. This article further details the differences between lanes, streets, circles, drives and more.

Today's cars use turbocharged hybrid engines and AI-assisted technologies

In addition to enhanced speed, serious accidents and technological advances have led to major innovations, leading to more aerodynamic and more protective cars.

NASCAR’s SAFER barriers help reduce tragedies at races

Following the death of Dale Earnhardt Sr. in 2001, NASCAR changed its culture to be safety-first. Part of its changes were to install barriers along tracks that would help absorb the majority of g-forces in a crash. This Daily Downforce article walks through the history of the SAFER barriers, why NASCAR originally chose concrete, and how much of the tracks are covered today.

Ingenuity and advanced engineering have allowed trains to overcome extreme landscapes

The Jungfrau Railway utilizes electric trains powered by hydroelectric energy to ascend the Swiss Alps, while Poland's Elbląg Canal hauls ships along cable-powered tracks driven by waterwheels. Germany's Wuppertal monorail navigates bends as it glides over a river valley, and New Mexico's Holloman High-Speed Test Track can achieve speeds of Mach 8.6 for rocket sleds.

The origin of shortest-path algorithms and how they became optimized for navigation apps

In 1956, Dutch programmer Edsger Dijkstra spent about 20 minutes developing an algorithm to demonstrate how computers could quickly determine the shortest route between Rotterdam and Groningen. Since then, modified versions of Dijkstra's formulation comprise the processing backbone of systems such as Google Maps and Apple Maps.

Explore landforms that exist across America's national parks

Landforms are not just scenic vistas; they are geological storytellers that shape ecosystems, climates, and our understanding of Earth's history. In this comprehensive look at landforms from the National Park Service, you will learn not only about different types of American landforms, but you will understand how these geological features are shaped by various forces, how they reveal an area's geological history, and how they influence climate and ecology.

Explore NASCAR’s dozens of tracks across the US and Mexico

See detailed information on every track used for NASCAR’s top three divisions. Tracks vary in shape, length, and seating capacity.

Every type of US national park, explained

Ever wonder what kinds of sites comprise the US National Park System? Using the recent re-designation of New River Gorge as a national park as a jumping-off point, this engaging video breaks down the 19 different designations within the National Park System. This includes parks, reserves, monuments, and scenic trails.

The US air traffic control system is safe but due for major technological updates

On any given day, over 3 million passengers fly on roughly 45,000 flights in the US. Flying today is safer than ever, but air traffic controllers deal with outdated technology that can interfere with pilot communication.

Read a complete history of urban mass transit in the United States

Explore the rise and fall of American mass transit, from the horse-drawn omnibus era through the streetcar age to the automobile's dominance. In the 1920s, streetcars carried 12 to 13 billion riders per year. By 1963, that number had shrunken to 300,000.

See how local, state, and federal governments divide the cost of public services

Federal, state, and local governments share responsibility for funding public services. Education, roads, and social programs are funded through a complicated mix of taxes and intergovernmental transfers.

Learn about the construction of the undersea fiber optic cables carrying internet data

Over 750,000 miles of fiber-optic cables run along the seafloor, serving as a freeway for the Internet's data. Despite subsea cable projects costing hundreds of millions of dollars, depending on the length of the cable, it remains the fastest and most cost-effective way to send information.