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Highways Timeline


A reliable network of roads, bridges, and tunnels is so fundamental to any country's economic and social well-being that some of the greatest engineering feats of all time have involved solving the problem of how to get from Point A to Point B—or rather, how to get over, under, around, or through some natural obstacle in order to go from Point A to Point B. Before the advent of the automobile, roads in the United States amounted to little more than a collection of dusty two-lane trails and occasional short bridges. Today, thanks to 20th-century civil engineers, the driving public can travel coast to coast on a world-class interstate highway system that includes bridges and tunnels of phenomenal strength and beauty.

  1905   Office of Public Roads

The Office of Public Roads (OPR) is established, successor to the Office of Road Inquiry established in 1893. OPR’s director, Logan Waller Page, who would serve until 1919, helps found the American Association of State Highway Officials and lobbies Congress to secure the Federal Aid Highway Program in 1916, giving states matching funds for highways.

  1910   Asphalt manufactured from oil-refining byproducts

Gulf Oil, Texas Refining, and Sun Oil introduce asphalt manufactured from byproducts of the oil-refining process. Suitable for road paving, it is less expensive than natural asphalt mined in and imported from Venezuela. The new asphalt serves a growing need for paved roads as the number of motor vehicles in the United States soars from 55,000 in 1904 to 470,000 in 1910 to about 10 million in 1922.

Garrett Morgan, an inventor with a fifth-grade education and the first African-American in Cleveland to own a car, invents the electric, automatic traffic light.

  1913   First highway paved with portland cement

The first highway paved with portland cement, or concrete, is built near Pine Bluff, Arkansas, 22 years after Bellefontaine, Ohio, first paved its Main Street with concrete. Invented in 1824 by British stone mason Joseph Aspdin from a mix of calcium, silicon, aluminum, and iron minerals, portland cement is so-named because of its similarity to the stone quarried on the Isle of Portland off the English coast.

  1917   Wisconsin adopts road numbering system

Wisconsin is the first state to adopt a numbering system as the network of roads increases. The idea gradually spreads across the country and replaces formerly named trails and highways.

  1919   MacDonald appointed head of federal Bureau of Public Roads

Thomas MacDonald is appointed to head the federal Bureau of Public Roads (BPR), successor to OPR. During his 34-year tenure he helps create the Advisory Board on Highway Research, which becomes the Highway Research Board in 1924 and the Transportation Research Board in 1974. Among other things, BPR operates an experimental farm in Arlington, Virginia, to test road surfaces.

  1920   Yellow traffic lights

William Potts, a Detroit police officer, refines Garrett Morgan’s invention by adding the yellow light. Red and green traffic signals in some form have been in use since 1868, but the increase in automobile traffic requires the addition of a warning signal.

  1923   Uniform system of signs

State highway engineers across the country adopt a uniform system of signage based on shapes that include the octagonal stop sign.

  1925   Numbering system for interstate highways

BPR and state highway representatives create a numbering system for interstate highways. East-west routes are designated with even numbers, north-south routes with odd numbers. Three-digit route numbers are given to shorter highway sections, and alternate routes are assigned the number of the principal line of traffic preceded by a one.

  1927   Holland Tunnel

Completion of the Holland Tunnel beneath the Hudson River links New York City and Jersey City, New Jersey. It is named for engineer Clifford Holland, who solves the problem of venting the build-up of deadly car exhaust by installing 84 electric fans, each 80 feet in diameter.

  1930s (Late)   Air-entrained concrete introduced

Air-entrained concrete, one of the greatest advancements in concrete technology, is introduced. The addition of tiny air bubbles in the concrete provides room for expansion when water freezes, thus making the concrete surface resistant to frost damage.

  1932   Autobahn opens

The opening of a 20-mile section of Germany’s fledgling autobahn, regarded as the world’s first superhighway, links Cologne and Bonn. By the end of the decade the autobahn measures 3,000 kilometers and inspires U.S. civil engineers contemplating a similar network. Today the autobahn covers more than 11,000 kilometers.

  1937   Route 66 completed

The paving of Route 66 linking Chicago and Santa Monica, California, is complete. Stretching across eight states and three time zones, the 2,448-mile-long road is also known as "The Mother Road" and "The Main Street of America." For the next half-century it is the country’s main thoroughfare, bringing farm workers from the Midwest to California during the Dust Bowl and contributing to California’s post-World War II population growth. Officially decommissioned in 1985, the route has been replaced by sections of Interstate-55, I-44, I-40, I-15, and I-10.

  1937   Golden Gate Bridge

The Golden Gate Bridge opens and connects San Francisco with Marin County. To construct a suspension bridge in a region prone to earthquakes, engineer Joseph Strauss uses a million tons of concrete to hold the anchorages in place. Its two main towers each rise 746 feet above the water and are strung with 80,000 miles of cable.

  1940   Pennsylvania Turnpike

The Pennsylvania Turnpike opens as the country’s first roadway with no cross streets, no railroad crossings, and no traffic lights. Built on an abandoned railroad right of way, it includes 7 miles of tunnels through the mountains, 11 interchanges, 300 bridges and culverts, and 10 service plazas. By the mid-1950s America’s first superhighway extends westward to the Ohio border, north toward Scranton, and east to Philadelphia for a total of 470 route miles.

  1944   Federal Aid Highway Act

The Federal Aid Highway Act authorizes the designation of 40,000 miles of interstate highways to connect principal cities and industrial centers.

  1949   First concrete pavement constructed using slipforms

The first concrete pavement constructed using slipforms is built in O’Brian and Cerro Counties, Iowa.

  1952   Walk/Don’t Walk signal

The first "Walk/Don’t Walk" signal is installed in New York City.

  1952   Chesapeake Bay Bridge

The Chesapeake Bay Bridge, the world’s largest continuous over-water steel structure, opens, linking Maryland’s eastern and western shores of the bay. Spanning 4.35 miles, the bridge has a vertical clearance of 186 feet to accommodate shipping traffic. In 1973 another span of the bridge opens to ease increasing traffic. By the end of the century, more than 23 million cars and trucks cross the bridge each year.

  1956   New Federal Aid Highway Act

President Dwight D. Eisenhower signs a new Federal Aid Highway Act, committing $25 billion in federal funding. Missouri is the first state to award a highway construction contract with the new funding. The act incorporates existing toll roads, bridges, and tunnels into the system and also sets uniform interstate design standards.

  1956   Lake Pontchartrain Causeway opens

Lake Pontchartrain Causeway opens, connecting New Orleans with its north shore suburbs. At 24 miles it is the world’s longest over-water highway bridge. Made up of two parallel bridges, the causeway is supported by 95,000 hollow concrete pilings sunk into the lakebed. It was originally designed to handle 3,000 vehicles per day but now carries that many cars and trucks in an hour.

  1960s   Reflective paint for highway markings developed

Paint chemist and professor Elbert Dysart Botts develops a reflective paint for marking highway lanes. When rainwater obscures the paint’s reflective quality, Botts develops a raised marker that protrudes above water level. Widely known as Botts’ Dots, the raised markers were first installed in Solano County, California, along a section of I-80. They have the added benefit of making a drumming sound when driven over, warning drivers who veer from their lanes.

  1962   Pavement standards

The AASHO (American Association of State Highway Officials) road test near Ottawa, Illinois, which subjects sections of pavements to carefully monitored traffic loads, establishes pavement standards for use on the interstate system and other highways.

  1964   Chesapeake Bay Bridge- Tunnel opens

The Chesapeake Bay Bridge-Tunnel opens, connecting Virginia Beach and Norfolk to Virginia’s Eastern Shore. Its bridges and tunnels stretch 17.6 miles shore to shore and feature a pair of mile-long tunnels that run beneath the surface to allow passage above of commercial and military ships. In 1965 the bridge-tunnel is named one of the "Seven Engineering Wonders of the Modern World" in a competition that includes 100 major projects.

  1966   Highway Safety Act

The Highway Safety Act establishes the National Highway Program Safety Standards to reduce traffic accidents.

  1973   Interstate 70 opens west of Denver

Interstate 70 in Colorado opens from Denver westward. It features the 1.75-mile Eisenhower Memorial Tunnel, the longest tunnel in the interstate program.

  1980s and 1990s   Introduction of the open-graded friction course

Introduction of the open-graded friction course, allowing asphalt to drain water more efficiently and thus reducing hydroplaning and skidding, and Superpave, or Superior Performing Asphalt Pavement, which can be tailored to the climate and traffic of each job, are among refinements that improve the country’s 4 million miles of roads and highways, 96 percent of which are covered in asphalt. By the end of the century, 500 million tons of asphalt will be laid every year.

  1986   Fort McHenry Tunnel in Baltimore opens

The Fort McHenry Tunnel in Baltimore opens and at 1.75 miles is the longest and widest underwater highway tunnel ever built by the immersed-tube method. The tunnel was constructed in sections, then floated to the site and submerged in a trench. It also includes a computer-assisted traffic control system and communications and monitoring systems.

  1987   Sunshine Skyway Bridge completed

The Sunshine Skyway Bridge is completed, connecting St. Petersburg and Bradenton, Florida. At 29,040 feet long, it is the world’s largest cable-stayed concrete bridge. Twenty-one steel cables support the bridge in the center with two 40-foot roadways running along either side of the cable for an unobstructed view of the water.

  1990s   Big Dig begins

Work begins in Boston on the Big Dig, a project to transform the section of I-93 known as the Central Artery, an elevated freeway built in the 1950s, into an underground tunnel. Scheduled for completion in 2004, it will provide a new harbor crossing to Logan Airport and replace the I-93 bridge across the Charles River.

  1993   Interstate system praised

Officially designated the Dwight D. Eisenhower System of Interstate and Defense Highways, the interstate system is praised by the American Society of Civil Engineers as one of the "Seven Wonders of the United States" and "the backbone of the world’s strongest economy."

  1993   Glenn Anderson Freeway/Transitway opens

The Glenn Anderson Freeway/ Transitway, part of I-105, opens in Los Angeles, featuring a light rail train that runs in the median. Sensors buried in the pavement monitor traffic flow, and closed-circuit cameras alert officials to accidents.


     Early Years
     WWI Lessons
     Growing Network
     Ongoing Improvement
     Essay - Stephen D. Bechtel, Jr.

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