If you've driven across the US—or even across a state line or two—you've probably noticed that the roads you're driving on suck. They suck more more than a string of gas station bathrooms, more than hundreds of bug carcasses on your windshield.
Our roads are riddled with potholes and cracks and bumpy asphalt band-aids over more potholes and cracks. It's bad. And it's our fault.
Once upon a time, our roads were even worse. In 1919, the War Department organized a 72-vehicle convoy to go from east coast to west as a sort of army toughness publicity stunt. A young Dwight Eisenhower, then a lieutenant colonel in the army, volunteered to go along. Sure, the east coast had lots of paved roads, but west of the Mississippi it was sand paths for miles. It took the group two months to get from Washington DC to San Francisco—3200 miles at an average speed of 6 miles per hour. As Geoffrey Perret points out in his Ike biography, "The world's richest country slowed down by some of the world's worst roads."
Fast forward almost 40 years and the 34th president was finally in a position to do something about the problem. Between Eisenhower's push in the 1950s and now, the Interstate Highway System has laid 42,795 miles of roads across the country. The goal was to get them down as quickly as possible, which turned the future into something a lot less far away. These roads were not build to last forever—not even close.
But the network was immediately awesome for cars. Before roads, ahem, paved the way for a trucking industry, freight was most often transported across country by train. The trains did the job, but they were a time suck. Whenever a container needed to get dropped off, the train had to be disassembled and then reassembled. Companies quickly realized that, in many cases, the interstate was a speedier option. "Picture yourself as a manufacturer of goods," says Tim Lomax, a research engineer at the Texas Transportation Institute. "You have a mode of transportation with more control over delivery time, which rail roads couldn't provide."
Planners of the country-wide network did not predict the massive shipping shift from rail to the road, so the damage inflicted by trucks was quick. See, 80,000 pound big rigs don't just do 40 times the damage of 2000 pound cars; because of the way the weight is distributed, the effect is, in fact, much more severe.
Exhibit A: the pothole. When a road is not properly sealed, water or ice can sneak underneath the asphalt, settling into the then-tiny void between the pavement and whatever is used as a base for the road. In the quickly-constructed roads of America, this is usually compacted dirt. Then, "when big trucks drive over a section of pavement, it pushes down on that water pocket," explains Lomax. "The water has to go somewhere." Now put yourself in the water's place: Where would you go? Up, through the asphalt, or down into the dirt, aided by gravity and the pressure from above. Exactly. The water goes down, and it forces some dirt out of its way in the process, creating an enlarged pocket underneath the pavement. The water or air pocket beneath the road will eventually allow what's on top of it to crack. And the more pressure on the rift and the space below it, and the bigger the hole.
Road-building is a kind of prediction game that tries to balance initial construction cost with continuing maintenance. Build a very thick road with a solid foundation—like what the Germans have done with the Autobahn—and the road wont need as much continuing maintenance. That means cracking and caving happens less often because the roads are designed to be more difficult for water to get down under. But build a thinner road with a less stable foundation, and you're looking at lots of regular upkeep.
The solution seems simple. The trouble is that building a truly sturdy road requires a bunch of money up front, something tax payers balk at. So instead we straddle that line between initial and follow-up costs. The current balance shoots for about a 30-year road life, which is really a measure of expected load.
Before a new road is built, engineers predict how much and what kind of use it's going to get. This is fine if an area's expected growth stays on track, but say a new suburb springs up or a massive manufacturing facility is constructed, then suddenly the stretch of road is flooded with more vehicles than it can handle. When the load increases dramatically, it increases the amount of upkeep and shortens the road's expected life. Furthermore, where construction is involved, what is often left off of the balance sheet is how much travelers lose in gas and time. Our pocket books are essentially being hit twice.
"The challenge is that the roads are always in some sense of a reactive mode to what businesses want to do," explains Lomax. "The transportation network is being used to help companies make more profit. That's a difficult trend to resist." He points to ‘just in time manufacturing,' where each individual part is made at its own plant and then trucked to another plant for rapid assembly, as a recent example of how companies are pushing the limits of what our roads can take, which increases their profits—but at the taxpayer's expense.
So again: it's our fault. We cut corners early on so it looks better on the budget. But a bigger investment in the infrastructure that makes us money might only bring in more. Of course that would mean starting from scratch. In the mean time, can anyone get this road a band-aid?