FOR a country as wealthy as America, the dilapidated state of its infrastructure sure is a sorry sight. Three weeks of motoring around Spain—an economic basket-case by comparison, with over twice the unemployment and less than two-thirds the per-capita income of the United States—has been an eye-opener for Babbage. Wide, well-engineered roads criss-cross the country, with clover-leaf accesses everywhere, and modern concrete bridges spanning ravines and gullies. Babbage returned to the crumbling freeways and surface streets of California more despondent than ever.



Once the envy of the world, America’s 47,000 miles (75,000km) of interstate highways and 115,000 miles of freeways and other dual-carriageways were built in a furious burst of road construction during the 1950s and 1960s. Half a century of heavy use later, and with little maintenance in between, America’s arteries have become clogged and cracked. “We’ve got about $2 trillion of deferred maintenance,” President Obama warned recently. The figure comes from a detailed study by the American Society of Civil Engineers. So far, however, the president's plea to a divided Congress for $50 billion to begin fixing the country’s ageing infrastructure has fallen on determinedly deaf ears.



Potholed roads take their toll on people’s vehicles, increasing maintenance costs, making motoring more hazardous than it need be, and causing untold delays. The more time people spend sitting in traffic, the more they spend on fuel, and the more pollution they produce in the process. Such things impose costs both on individuals and on society at large.



Faulty bridges impose even greater costs. When the I-35W bridge in Minneapolis collapsed into the Mississippi River in 2007, the catastrophe took 13 lives, injured 145 others and cost taxpayers $234m—not counting the months of delays and diversions. Failures among the country’s 600,000 or so bridges are increasing alarmingly. Two thirds have exceeded their normal life expectancy.



Not counting the 84,000 bridges connecting main arteries that are classified as “functionally obsolete” (meaning they can remain open, provided suitable weight and speed restrictions are enforced), there are a further 66,500 major bridges with known structural defects. Just fixing the backlog of these defective structures was estimated in 2004 to cost taxpayers $32 billion (see “A member too few”, June 3rd 2013). Today, the bill is considerably higher.



Unfortunately, the Highway Trust Fund, set up in 1956 to pay for building and maintaining the country's infrastructure, is on the verge of bankruptcy. When the money runs out next September, the federal government will be unable to reimburse states for much of the road construction and maintenance work already underway.



The fund is financed through an 18.4 cents a gallon (4.9 cents a litre) tax on petrol and 24.4 cents a gallon on diesel. The states and local authorities add their own taxes on top of that. California has the stiffest, with a combined total of 71.9 cents a gallon for petrol and 74.9 cents for diesel. The national average is around 50 cents a gallon on petrol and 55 cents on diesel.



Taxing fuel is one of the more efficient ways of getting motorists to pay for public infrastructure. Collected at the pump, the tax is cheap to administer, difficult to avoid, and charges only for what the consumer actually uses. But not all taxes collected at the pump are ploughed back into infrastructure. The state and local taxes on fuel, unlike the federal ones, can be used for other purposes, and frequently are.



To add to the problem, the federal fuel tax has not been increased since 1993. Nor is it indexed for inflation. And on top of that, motorists are not buying as much fuel as they used to do. Tax revenues have declined as vehicles have become more efficient. On average, cars today use 25% less fuel than they did 20 years ago, despite having become heavier and more powerful.



Serious attempts have been made over the years to raise the federal fuel tax incrementally to around 40 cents a gallon. With today’s bitterly divided Congress, that is more of a political non-starter than ever. Instead, the best that can be expected is that Congress will kick the can down the road, with a stop-gap measure to tide the Highway Trust Fund over for another year or so. Since 2008, the United States Treasury has had to transfer $41 billion to the Highway Trust Fund to stop it becoming insolvent. By the end of next year, that figure will have risen to $54 billion.



The real answer, of course, is to index the fuel tax for inflation, while incorporating adjustments for rising fuel-efficiency. As that is unlikely to happen (for the same reason it is impossible to raise fuel taxes), an alternative is to replenish the Highway Trust Fund with revenue raised by charging motorists a “user fee” for the miles they travel. And if Congress baulks at that, then the states need to be encouraged—and rewarded—for implementing their own user-based sources of revenue for road construction and maintenance.



Facing the possibility of not being paid for road work underway, a number of state and local governments have started experimenting with ways of monitoring motorists' mileage. The equipment being tested is similar to the telematic tracking devices used by insurance companies to offer lower premiums to customers willing to prove they drive carefully, within the law, and only during hours of daylight.



The “black box” used to track a customer's driving habits contains accelerometers, a GPS receiver, a processor and memory module, plus a cellular modem for beaming recorded data back to the insurance company. The device keeps track of the vehicle’s location, speed and acceleration as well as the braking and cornering forces, along with the time of day. Knowing where the vehicle has been and when, and how carefully it has been driven, allows the insurance company to set the premium accordingly. Careful drivers can get up to a 50% reduction in rates. Telematic insurance is handy for young drivers, who are not penalised for their age, job and type of vehicle.



The one thing motorists universally dislike about tracking devices in their vehicles—even if they lower insurance rates significantly—is that they are, well, tracking devices. With the National Security Agency’s clandestine data collection in the headlines daily, people fear that the GPS location data could be used to monitor their every move and used against them in some way. No surprise, then, that fears about Big Brother have bothered drivers participating in user-fee experiments as well.

Such trials are planned or underway in Oregon, California, Nevada, Minnesota, Illinois and New York, as well as Pennsylvania, Maryland, Virginia, Florida and other “I-95 Coalition” states on the eastern seaboard. In California, transport planners are hoping to adopt road-user fees that vary by the hour of day also to ease congestion, as well s help the state comply with its global-warming goals. Drivers who are deterred by higher rush-hour user fees from travelling during the busiest times are likely to use less fuel and emit less pollution.



The Oregon experiment—the most comprehensive in the country—involves some 5,000 drivers. To minimise the privacy issue, planners there are experimenting with giving motorists the option of having a mileage-measuring device with or without GPS; alternatively, they can choose not to have it at all, and pay a flat fee based on the average mileage of the whole group.



Meanwhile, Nevada and other states are looking at ways of dispensing with GPS altogether. They want to see whether it is possible to log the number of miles a vehicle is driven, without collecting data on where it went and when. Doing so makes motorists more comfortable. “People will be more willing to do this [ie, accept mileage-based user fees] if you do not track their speed and you do not track their location,” Ryan Morrison, president of True Mileage, told the Los Angles Times recently.



True Mileage, a start-up based in Oakland, California, has developed a mileage-based logging device for taxi services and insurance firms. The technology uses neither a GPS radio for triangulating the vehicle’s location, nor a cellular modem to beam back a stream of data on the driver’s behaviour behind the wheel. The only on-board information recorded is the vehicle’s mileage by the hour of day, and the number of times the driver hits the brakes. Analytical algorithms extract additional meaning from the accumulated data.



A summary of the user's mileage is uploaded once or twice a year to the company’s servers, simply by holding a smartphone equipped with “near-field communication” close to the monitoring device. Insurance companies use the data to determine the discount they can offer customers when their policies come up for renewal.



True Mileage’s technology looks a good deal cheaper and less intrusive than any of today’s GPS tracking systems. If trials prove it to be accurate and reliable enough for widespread deployment, then state and local transport departments could well have a solution for implementing mileage-based user fees, without causing undue alarm among the motoring public. If that helps fill the coffers for rebuilding America’s crumbling infrastructure, all to the good. Perhaps then the Highway Trust Fund would no longer be needed. Now there's a thought.