The US has over 4 million miles of roads. 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

In 2023, self-driving cars drove 3.3 million miles on California's roads

According to the state's DMV, the mileage represented a fivefold increase from the previous year. General Motors' Cruise and Alphabet's Waymo accounted for the bulk of miles, though 38 companies have received permits to test autonomous vehicles in the state.

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.

Multiple legal pathways exist for immigrating to the United States

This comprehensive guide outlines various routes to US immigration, including family-sponsored and employment-based visas, as well as humanitarian protections. Navigate the complex American immigration system and understand the options available to prospective immigrants seeking legal entry.

Stanford built a Google Maps for the Roman Empire, revealing how much it cost to travel in the ancient world

The seven major US freight rail companies

The US railroad industry is dominated by seven long-running freight conglomerates. Get the basics on each of these companies with this brief overview.

The US shipped nearly 4 billion barrels of oil abroad in 2024

More than half of the US’s oil is exported as the country produces mainly light, sweet crude but has many refineries that handle heavy, sour types.

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.

Explore US public health data

This resource tracks key US health metrics, including mortality causes, child survival rates, and life expectancy comparisons, to inform future health improvements, with regularly updated global estimates.

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

One reason Americans are bad at math

The president of Barnard College explains why we need to better understand the links between math anxiety, math avoidance, and the US’s dismal test scores.

States with the most million-dollar homes

As of 2024, the US has 621 cities where a typical home costs $1M or more. California has more million-dollar cities than any other state by a long shot, with 218. New York comes in second with 76. Want to see where other states rank? Check out this map to learn more.

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.

George Washington was an expert in maps and cartography

Trained as a surveyor, Washington routinely studied, annotated, and drew maps throughout his life. He relied on cartography to navigate frontier lands, plan military campaigns across vast distances, and make strategic decisions on borders, settlement, and governance.

Atmospheric rivers are the largest freshwater transport mechanism on Earth

Serving as highways that carry the water vapor equivalent of up to 15 times the average flow of water at the mouth of the Mississippi River, atmospheric rivers are approximately 400 to 600 kilometers (250 to 375 miles) wide and provide 30-50% of the annual precipitation of the US West Coast.

States are constitutionally mandated to draw their own congressional districts

Under Article I, Section 4 of the US Constitution, state legislatures possess the authority to determine how congressional districts are drawn. However, Congress retains the power to alter these rules if it chooses to.

Taxicab geometry defines displacement as the sum of vertical and horizontal distances

In this mathematical system, pi is valued at four, and circles aren't round—they appear as diamonds with corners instead. The system simplifies pixel distances in digital imaging and helps engineers with robot navigation and chip design.

The United States is one of only around two dozen countries with a fully federal system of government, in which power is divided between national and state governments.

Hear about the 250-year history of the United States Postal Service, complete with some of its strangest deliveries, important innovations, and the figures that made it an American institution.

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

Power lines are dotted with large, brightly colored balls to improve the visibility of these thin wires to helicopters and small planes and help prevent potential crashes.

Roughly 43 million US borrowers owe roughly $1.7T in student debt, the second-largest source of consumer debt behind mortgages.

Explore an interactive map of battles from the American Revolution, along with detailed summaries of each engagement

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

Some coin denominations have ridges etched on their sides, partly to prevent counterfeiting, in a practice called 'reeding.'

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

The US first hosted the World Cup in 1994, a tournament that lives in soccer infamy for its poor planning and the murder of Colombian player Andres Escobar, who'd accidentally scored on his own net.

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

A Yale student wrote a profound essay about the consulting industry's influence on elite college students that was published in a book of her writing after she died in a post-graduation car accident.

Hurricanes, which rely on air consistently spinning in the same direction, cannot cross the equator because air curves in opposite directions north and south of it.

Experimental hantavirus vaccines and therapies, still under development, have long been funded by the US military.

'Grand Canyon of the Yellowstone,' a work by American painter Thomas Moran, inspired Congress to establish Yellowstone National Park.

Abraham Lincoln was almost assassinated weeks before his inauguration as he traveled from Illinois to DC through Baltimore in 1861; it took two independent claims for Lincoln to be convinced the threat was real

See how each of the more than two million known species relates to each other—and to common ancestors—in this zoomable tree of life.

See how Budweiser's famous Clydesdales spend their days at Warm Springs Ranch, where roughly 70 to 80 of the beer brand's giant horses can be found at any given time.

Legendary architect Frank Lloyd Wright designed the SC Johnson headquarters in Wisconsin, aiming to make a cathedral-like workplace