Why America Has So Many Potholes

  • For a seat-of-the-pants introduction to America's highway misery, try rattling down the joint-jangling Southwest Freeway in the shadow of the Washington Monument. On this long-neglected strip of pavement, a washboard ripple effect experts call rutting jiggles the front wheels into a dervish dance. Farther along in a newly rebuilt section, potholes already lurk, like so many blacktop booby traps.

    America's road system is a marvel and a mess. With 3.9 million miles of highways and roads, many of them built in the asphalt rush of the 1950s, it is by far the world's biggest system. Ninety percent of all U.S. travel occurs on highways, and three-quarters of all domestic goods are shipped by road. No stretches are busier than the 1.2 million miles of interstate and other major highways. And yet, despite the $28 billion spent each year on maintenance and construction, the Federal Highway Administration admits that 52% of these thoroughfares are in miserable condition. Some are rated "low fair," meaning rutted, cracked and sometimes "unfit for high-speed travel." Others are "poor," meaning they have excessive bumps, depressions and potholes that "provide an uncomfortable ride." Roads like this contribute to congestion and accidents, which the government says cost the country $120 billion a year -- and untold lives.

    Highways in rotten condition are scattered across the nation. I-35 south of Kansas City, Kans., is known as a deathtrap for shock absorbers, while the pockmarked I-5 south of Portland, Ore., and I-20 in Louisiana are renowned for testing drivers' nerves and fannies.

    Highway experts often blame such conditions on the unexpectedly heavy pounding delivered by American traffic, especially from behemoth 18-wheelers. Many U.S. roadways carry three or even four times their design weights. "Nobody in their wildest imagination predicted these load factors," says federal highway administrator Thomas Larson.

    But such excuses won't fly in Europe, where miles of smooth-riding, durable autobahns and auto routes put American roadways to shame. European highways actually carry more traffic and considerably heavier truck weights than U.S. roads, yet they are smoother and far sturdier. European highways are designed by their builders to last 40 years; the projected life of American roads is half as long.

    Why has the world's highway Goliath become the superpower of potholes? A major reason is that in its haste, America built on the cheap. Across the nation, state and local governments have tended to award competitive contracts to the lowest bidder, often meaning they got the shoddiest materials and the sloppiest work. In addition, the Federal Government has encouraged neglect by subsidizing new construction or major restructuring at 90 cents to the dollar but awarding no subsidies for maintenance work. One expert likens it to not reimbursing drivers for the cost of changing oil in their cars while paying 90% of the price of a valve job. "The attitude was the faster it crumbles, the faster we'll get brand-new," says New York Senator Daniel Patrick Moynihan, a stalwart highway watcher. Moreover, maintenance is unglamorous. "Nobody ever had a ribbon-cutting ceremony for fixing cracks," notes Moynihan.

    In Europe, by contrast, maintenance and repair work begin before damage is even visible. During a 1990 study trip to Europe, a group of U.S. civilian and government experts was amazed to see maintenance work under way on highways considered to be in superb condition by American standards.

    Given the emphasis on new construction, U.S. highway designers have badly neglected research and development, which might have kept the roads abreast of mounting traffic. "For many years, the Department of Agriculture spent more % researching dog food than the Department of Transportation did on highways," says Thomas Deen, executive director of the Transportation Research Board. Europeans routinely spend 20 times as much per capita on R. and D. Contractors in Europe add innovative polymers to asphalt and mix new additives into concrete. One additive developed in France -- based on a complex polymer akin to shredded Tupperware plastic -- increased construction costs 8% while doubling the life of a road.

    But some of the most important differences between American and European expressways lie well beneath the surface. All highways are built by bulldozing softer subsoils and either tamping them or replacing them with more durable dirt or gravel. But in Germany the roadbeds tend to be 1.5 m or 1.8 m (5 ft. or 6 ft.) deep, twice the U.S. average. European engineers also devote more time and money to designing roadbeds that resist frost and have excellent drainage, addressing two problems that play havoc with U.S. thoroughfares. Each step, from laying the subsequent gravel or concrete layer to applying the asphalt surface, is taken with long-term durability in mind.

    In the past few years, U.S. engineers and contractors have begun to apply some of the lessons from overseas, particularly in improving materials. Asphalt, a heavy petroleum residue that is typically mixed with crushed rock or even slag from steel mills, can be made much stronger and more durable by adding various polymers, including polyurethane. About half of new roads are built with asphalt (the other half are concrete), and nearly 90% of resurfacing jobs employ the sticky material.

    American contractors are gradually introducing stone-matrix asphalt, a surfacing mixture embedded with uniformly sized rocks that help the material hold together better and last longer. Road technicians are also experimenting with a more porous asphalt that provides an anti-skid surface and has the added benefit of reducing noise. And to cut costs, builders have developed imaginative ways to recycle old chunks of asphalt.

    Concrete -- a mixture of cement, sand and gravel -- has also been enhanced. A slew of additives, such as fine steel or urethane fibers, have toughened the product and lengthened its service life. To minimize traffic disruptions during repair, some quick-drying concretes cure so rapidly that highways can be opened to traffic within an hour. New bonding techniques enable concrete to adhere to old concrete slabs, which means the old layers don't have to be laboriously removed. U.S. contractors have begun to use new equipment that accelerates the laying process, including one colossus that spews out two parallel 3.7-m-wide (12-ft.-wide) strips of wet concrete like newspapers off a press.

    Alas, few of these improvements are landing where the rubber meets the road, because American contracting procedures discourage the use of novel techniques. In Europe, governments dictate only how long a highway should last under what conditions, and contractors are left to their own devices to deal with the challenge. In the U.S., contractors must meet an avalanche of government specifications on materials and procedures but are not required to guarantee the road's performance. "The Europeans create a contract climate that stimulates innovation; here we squash it," laments Douglas Bernard, director of the Office of Technology Applications in the Federal Highway Administration.

    Bernard and other highway officials would like to see the U.S. move to a performance-contract system, similar to one advocated by the National Academy of Sciences, but they face roadblocks from builders. Heavy lobbying from the construction industry eliminated such a provision in the 1991 federal highway act, passed last fall. The industry especially dreads being asked to guarantee the life-span of its products, arguing that it is unreasonable without knowing for certain what the traffic will be like, despite the fact that European contractors routinely make these assurances. Such warranties, insists David Lukens of the Associated General Contractors of America, are "an invitation to litigation and a field day for lawyers."

    In fact, many U.S. road builders are small mom-and-pop operations that would be hard pressed to pay for the new equipment and training that innovative techniques sometimes require, let alone to post the insurance bond necessary to guarantee their product over several years. In France, by contrast, the highway-construction business is dominated by half a dozen or so well-financed giants.

    The 1991 highway act does address some of the problems with American road building by giving more emphasis to maintenance and research and development. In part, the government is recognizing the exciting possibilities that truly lie down the road: innovations that go well beyond surface improvements. Initial government contracts are already out for an "intelligent vehicle" system involving electronics embedded in roadways that will someday permit drivers to punch in their destinations and watch TV or snooze while their cars or trucks race merrily on their way. But before the country can turn to such 21st century roadway wizardry, it must first win the battle against pesky and dangerous potholes.