The transportation of people and goods is in many ways a necessary evil. You rarely hear any person outside of car company advertisements bemoaning that their commute to work is too short, or that they wish it took a little longer to pick up bread and milk at the grocery. You never hear a business exalting that getting some parts or inputs from a distant location took especially long or required an especially high cost. Of course, there are sensible reasons why not all economic activity happens at one location and most people do not live immediately beside where they work; in effect, transportation is the cost we pay for the benefits that arise from this diversity of locations. Clifford Winston writes \”On the Performance of the U.S. Transportation System: Caution Ahead,\” in the most recent issue of the Journal of Economic Literature (51: 3, pp. 773–824). (Full disclosure: The JEL is a sibling journal of the Journal of Economic Perspectives, where I work, both published by the American Economic Association. The JEL is not freely available on-line, but many in academia will have access through library subscriptions or through their AEA membership.)
Winston summarizes some facts about the sheer size of the US transportation sector in 2007 an eye-opening paragraph (as usual, footnotes and references are omitted for readability):
\”[C]onsumers spent $1.1 trillion on gasoline and vehicles commuting to work, traveling to perform household chores and to access entertainment, and traveling for business and vacations, and spent an astronomical 175 billion hours in transit, which averages out to about 100 minutes per day for each and every American,valued at some $760 billion. Firms spent $1 trillion shipping products using their own and for-hire transportation, while the commodities that were shipped absorbed 25 billion ton-days in transit, valued at roughly $2.2 trillion. Local, state, and federal government spending on transportation infrastructure and services contributed an additional $260 billion, bringing total pecuniary spending on transportation up to 2.4 trillion, or 17 percent of GDP in 2007, which is as much as Americans spent on health care, and total annual money and time expenditures to more than $5 trillion! Finally, transportation looms large in American life because both the public and private sector have made huge investments in the transportation capital stock, which (after deducting depreciation) is valued by the U.S. Department of Commerce at nearly $4 trillion …\”
Many of these costs are not immediately apparent. After all, the transportation costs of firms are not costs that most of us see directly, but instead costs that are wrapped into the final cost of goods and services. The costs of time spent in traffic are not monetary costs. The link from transportation capital stock paid for in is government budgets and the tax revenues that ultimately support such spending is not especially clear.
Our public conversation about transportation policy often boils down to a claim that more government spending is good: fix and expand the road system, fix the bridges, build more mass transit, and so on. The transportation legislation that emerges from Congress every few years is perhaps the classic case of pork-barrel spending, usually with juicy tidbits for almost every legislative district. As one might expect, Winston takes a disciplined perspective: how can we set up institutions so that the transportation system works more efficiently, and so that additional infrastructure spending occurs when benefits are balanced against the costs, in a way that makes society more likely to focus on projects that have a higher payoff. Some of the possibilities that go beyond pouring more concrete include:
- Cars should be charged for driving during times when traffic is congested. When you drive during a time when congestion is high, you of course experience the costs of having lots of other drivers on the road. But you also play a role in imposing those costs of time and delay on others.
- Most big cities charge too little for street parking, at least during peak times For economists, when street parking is all taken for blocks around, and people are cruising the streets looking for a spot, it seems clear that the quantity of parking demanded is exceeding the quantity supplied at the existing price–and so the price should rise.
- \”The gasoline tax that truckers are charged for highway travel does not adequately account for their damage to pavements because that damage depends on a truck’s weight per axle (for a given weight, trucks with more axles inflict less pavement damage) and for their stress on bridges, which depends on a truck’s total weight.\” Higher charges would provide an incentive to use trucks with more axles, which would save wear and tear on roads and bridges.
- \”The charge that an aircraft pays public airports to land (they are not charged to take off) is based on its weight and generally does not vary by time of day. But the volume of aircraft traffic, which determines the length of time that a plane must wait on the ground or in the air, does. Efficient takeoff and landing (marginal cost) congestion charges that vary by time of day could significantly reduce air travel delays, generating a $6.3 billion annual welfare gain, accounting for the time savings to travelers and reduced operating costs to airlines …\”
- \”[U]sers of urban bus and rail transit pay fares that are set by transit authorities below marginal cost, some even ride at discounts from those fares, and some federal employees ride free. As pointed out later, such subsidies are hard to justify on distributional grounds because transit users generally live in households with incomes that are above the national average …\”
- \”Most highways in major metropolitan areas operate under congested conditions during much of the day, yet highway design standards are based on free-flow travel speeds. Policymakers could therefore reduce the cost of delays by expanding the range of alternative highway designs that, for example, could raise speeds during peak travel periods by increasing the number of lanes, although speeds during off-peak travel periods may be slower because lanes and shoulder widths would be narrower. Technology exists to install lane dividers that can be illuminated so that they are visible to motorists and that can be adjusted to increase or decrease the number of lanes that are available in response to traffic volume.\”
- \”[I]nvestments in highway durability—that is, pavement thickness—should minimize the sum of initial capital and ongoing maintenance costs. They determined that building roads with thicker pavement at an annualized cost of $3.7 billion would generate an annualized maintenance saving of almost 4 times as much—$14.4 billion—for a net annual welfare gain of $10.7 billion. Roads could also be made more durable by implementing innovations such as tack coats between pavement levels and thicker bottom layers of asphalt to avoid buckling, both of which can extend the functional life of a highway at little extra cost. But state departments of transportation award construction contracts on the basis of the minimum bid, not on the technological sophistication of the contractor …\”