Wednesday, February 26, 2014

Highways of the Future

Highways, roads, and bridges are are still mostly an early to mid-20th century technology.  Clifford Winston and Fred Mannering point to some of the directions for highways of the future in "Implementing technology to improve public highway performance: A leapfrog technology from the private sector is going to be necessary," published in the Economics of Transportation. They set the stage like this (citations and notes omitted throughout):

"The nation's road system is vital to the U.S. economy.Valued at close to $3 trillion, according to the Bureau of Economic Analysis of the U.S. Department of Commerce, 75 percent of goods, based on value, are transported on roads by truck, 93 percent of workers' commutes are on roads by private automobiles and public buses, and by far the largest share of non-work and pleasure trips are taken by road. Indeed, roads can be accurately characterized as the arterial network of the United States. Unfortunately,the arteries are clogged: the benefits that commuters, families,truckers,and shippers receive from the nation's road system have been increasingly compromised by growing congestion, vehicle damage, and accident costs."
These costs are high. Estimates of the value of time and fuel spent on congested roads are $100 billion per year. Poor road conditions cost American car drivers $80 billion in operating costs and repairs. And 30,000 Americans die in traffic fatalities each year.

Many of the policy recommendations are familiar enough. For example, the traditional economist's answer to road congestion is to charge tolls for driving during congested times. "[P]oor signal timing and coordination, often caused by outdated signal control technology or reliance on obsolete data on relative  traffic volumes, contributes to some 300 million vehicle hours of annual delay on major roadways." Earlier work by Winston emphasized that roads and bridges are primarily damaged by heavier trucks, not cars: "Almost all pavement damage tends to be caused by trucks and buses because, for example, the rear axle of a typical 13-ton trailer causes over 1000 times as much pavement damage as that of a car." Thus, charging heavy vehicles for the damage they cause is a natural prescription. For greater safety, enforcement of laws against drunk driving and driving-while-texting can be a useful step.

But as Winston and Mannering note, new technologies are expanding possibilities for the highway of the future. Certain technologies, like automated collection of tolls from cars that don't need to stop, are already widespread. The combination of GPS technology and information about road conditions is already helping many drivers find alternative routes through congestion. But more is coming. As they write:
"Specific highway and vehicle technologies include weigh-in-motion capabilities, which provide real-time information to highway officials about truck weights and axle configurations that they can use to set efficient pavement-wear charges and to enforce safety standards efficiently; adjustable lane technologies,which allow variations in the number and width of lanes in response to real-time traffic flows; new vehicle attributes, such as automatic vehicle braking that could decrease vehicle headways and thus increase roadway capacities; improved construction and design technologies to increase pavement life and to strengthen roads and bridges; and photo-enforcement technologies that monitor vehicles' speeds and make more efficient use of road capacity by improving traffic flows and safety. ... The rapid evolution of material science (including nanotechnologies) has produced advances in construction materials, construction processes, and quality control that have significantly improved pavement design, resulting in greater durability, longer lifetimes, lower maintenance costs, and less vehicle damage caused by potholes."
Of course, ultimately, the driverless car may dramatically change how cars and roads are used. (Indeed, driverless trucks are already in use in places like an iron ore mine in Australia, comfortably far from public roads--at least so far.)

But the roads and bridges are not a competitive company, trying out new technologies in the hope of attracting new customer and raising profits. They are run by government bureaucracies that are set in their old ways. The federal fuel tax isn't raising enough money for new investments in road technology, partly because it is fixed in nominal terms and inflation keeps eating away at its real value, and partly because higher fuel economy means that a fuel tax collects less money. Lobbies for truckers oppose charges that would reflect road damage; lobbies for motorists oppose charges that would reflect congestion. Stir up all these ingredients, and the result is not a big push for applying new technology to America's roads and bridges.

Winston and Mannering offer a ultimately optimistic view in which private investments in the driverless car trigger a wide array of other technological investments in roads and bridges. Maybe they will be proven right. I believe the social gains from applying all kinds of technology to roads and bridges could be very large. But I also envision a complex array of interrelated and potentially costly technologies, which would be confronting a thorny tangle of political and regulatory obstacles at every turn and straightaway.