Introduction and Overview

Introduction and Overview

Transportation gateways—seaports, airports, and land border crossings—are the entry and exit points for international merchandise trade between the United States and countries around the world. During the past decade, the leading U.S. gateways handled increasing volumes of freight as the movement of merchandise trade to and from our nation rose. Some facilities increased in relative importance, while others declined. Changes in freight movement influenced investment needs for air and marine facilities, land border crossings, and connecting infrastructure linking gateways to commercial and population centers.

From 1990 through 2003, the value of U.S. international merchandise trade increased from $889 billion to about $2 trillion (in current terms), growing at an average rate of 6 percent per year (table 1).1 For most years in the period, growth in trade was steadily up, with each year showing an increase over the prior year. The exceptions were 2001 and 2002, reflecting the impact on trade of a slow economy and the September 11 terrorist attacks. By 2003, trade had rebounded to 2000 levels in inflation-adjusted terms.

While over 400 U.S. seaports, airports, and land border crossings handle international merchandise trade, most of that trade ­passes through a relatively small number of gateways.

In 2003:

  • the nation’s top five freight transportation gateways, handled more than one-fourth ($533 billion) of the total value of U.S. international merchandise trade,
  • the nation’s top 14 gateways handled more than 50 percent of U.S. international merchandise trade, and
  • the top 50 gateways handled 80 percent ($1.6 trillion) of that trade.2

America’s Freight Transportation Gateways is a data profile of the nation’s leading international transportation gateways. It is a collection of information that highlights the top 25 freight gateways and provides the most recent annual information on the goods and infrastructure at these seaports, airports, and land border crossings (box 1). A companion Gateway Resource CD provides additional information on over 200 gateways that are key points of entry and exit for U.S. international trade.

The Nation's Top Freight Transportation Gateways

The U.S. air, land, and water transportation systems and the services they provide all play critical roles in U.S. international merchandise trade. Figure 1 shows the location, by value, of the nation’s top 25 ports of exit and entry for U.S. international trade shipments in 2003. In that year, the top three gateways represented the three transportation modes—water, air, and land:

  1. The Port of Los Angeles was the leading gateway for international trade with over $122 billion in oceanborne cargo.
  2. John F. Kennedy (JFK) International Airport ranked second in value with $112 billion in total trade.
  3. The land border crossing of Detroit ranked third with a total of $102 billion in export-import trade.

Table 2 shows that the top 50 freight gateways, ranked by value of total trade, are located in 21 states and Puerto Rico.

During the 1990s, JFK Airport was the leading gateway for overall merchandise trade by total value of shipments. In 2003, the Port of Los Angeles rose to the number one position, a notable change from 1999, when it ranked fourth. Between 1999 and 2003, imports at the Port of Los Angeles jumped 52 percent in value, while exports grew about 20 percent—an overall growth of 47 percent, far above the 14 percent average growth for the top 25 gateways (table 3). This growth reflects a major increase in trade with Asia and Pacific-Rim countries, especially growth in goods from China.

Both exports and imports pass through America’s freight transportation gateways. Some serve primarily as gateways for imports into the United States and others serve more as gateways for exports from the United States to markets around the world. But among the top 25 freight gateways in 2003, only three—the land port of Detroit, Los Angeles International Airport, and the Miami International Airport—handled more exports than imports in value terms (table 2).

Modal Shares

The U.S. water transportation system carries more trade, both in terms of tonnage and value, than any other mode (figure 2) 78 percent of the weight and 41 percent of the value of U.S. merchandise trade in 2003. Pound for pound, water cargo tends to be lower in value than cargo carried by other modes. Freight moving through land gateways accounts for 22 percent of the weight of overall U.S. trade, but 28 percent of the value.

In 2003 air cargo’s share of total trade tonnage was less than 1 percent , but that cargo accounted for 26 percent of the value of all U.S. trade.

Modes vary in the proportion of imports and exports they carry. While water transportation accounted for 79 percent of U.S. import tonnage and 74 percent of U.S. export tonnage in 2003, its share of the value of all U.S. imports was 48 percent and its share of all exports was 29 percent. By contrast, trucks moved 27 percent of the value of all exports and 17 percent of all imports.

Land Freight Gateways

In 2003, nearly one-third (32 percent) of the value of overall U.S. merchandise trade was with our two largest trading partners, Canada and Mexico, and was valued at $629 billion (table 4). Land trade—carried by truck, rail, and pipeline—accounted for 89 percent of this value, or $563 billion.3 Since 1990, the value of U.S. land trade with Canada and Mexico has grown at an average annual rate of 8 percent per year, compared with about 6 percent for overall U.S. trade with all countries (table 5). As a result of this growth, land trade’s share of the value of total U.S. merchandise trade grew from 23 percent in 1990 to 28 percent in 2003 (figure 3).4 Canada, Mexico, and the United States are all participants in the North American Free Trade Agreement (NAFTA), which was put in place by the three countries in 1994. For convenience, this report refers to U.S. trade with Canada and Mexico as U.S.-NAFTA trade.

Even though there are over 75 land ports along the U.S.-Canadian border and over 25 along the U.S.-Mexican border, the land freight transported across the northern and southern borders is heavily concentrated at a few major gateways. This concentration affects traffic and congestion at the border as well as the growth of major transportation corridors. In 2003, the top three ports for U.S.-NAFTA land trade by value were Detroit, Michigan; Laredo, Texas; and Port Huron, Michigan. In total, these three ports accounted for over 41 percent of the value of all U.S.-NAFTA land trade in 2003.

Most of the top U.S. land border ports serve as national and multistate regional trade gateways in addition to serving local markets. The proportions vary quite a bit among gateways. Only about 30 percent of the value of shipments passing through Detroit originates or terminates in Michigan. And, for Laredo, the biggest U.S.-Mexican border port, only 25 percent of the value of shipments start or end within Texas. By comparison, 91 percent of the freight shipments passing through Otay Mesa, the largest California port on the U.S.-Mexican border, originate or terminate in that state.

In value terms, trucks carried nearly three-quarters (72 percent) of all U.S. land trade, worth about $404 billion in 2003, up about 2 percent from 2002. Rail transborder freight climbed to $96 billion in 2003, a 4 percent increase from the previous year. Pipelines ­carried $32 billion worth of products, a 43 percent rise from 2002, primarily due to a rise in the value of U.S. imports of petroleum products from Canada.

Although trucks haul the majority of U.S. trade by value at the major land ports, many border crossings are important rail gateways, facilitating the transport of long-haul freight to and from origins and destinations in several states. Over half of the value of U.S.-NAFTA rail trade passes through just two gateways, Laredo, Texas, and Port Huron, Michigan. These two ports, along with Eagle Pass, Texas, have seen large growth in the value of rail cargo in recent years, in part due to rail privatization in Mexico and new North American rail alliances. Rail marketing alliances, such as the NAFTA Railway formed by Kansas City Southern and other rail lines, provide integrated service from the United States into Mexico and Canada with a single freight rate.5

By weight, land modes hauled over 254 million tons of imported goods entering the United States from Canada and Mexico in 2003, exceeding the 2000 level by nearly 4 percent (table 6). The tonnage of land imports from Canada grew 3 percent, while tonnage from Mexico grew about 7 percent.6 Regarding modal shares, in 2003 trucks moved 37 percent of the tonnage of total land trade imports, rail moved 32 percent, and pipelines accounted for 31 percent. Trucks hauled a larger percentage of the tonnage of U.S. land imports from Mexico (74 percent) than from Canada (32 percent). By comparison, in 2003 rail trans­ported 25 percent of the tonnage of land imports from Mexico and 33 percent from Canada.

Vehicle Crossings at the Land Gateways

Large numbers of vehicles and equipment carrying imported goods enter the United States each day. In 2003, there were ­nearly 11 million commercial truck crossings into the United States from Canada and Mexico, down 5 percent from the 11.6 mil­lion crossings in 2000 (table 7).7 Commercial trucks crossing into the United States at the busiest land gateways—Detroit, Michigan, and Laredo, Texas—generate heavy north-south truck traffic from Detroit through Memphis, Tennessee, and San Antonio, Texas, to Laredo. These commercial trucks entering the United States carried 8.3 million full containers and 2.6 million empty containers in 2003.

The land gateways also handled over 42,000 trains carrying about 2.5 million containers headed for the United States from Canada and Mexico in 2003 (approximately 114 trains and 6,700 containers per day). Nearly 34,000 of these trains entered from Canada. Between 2000 and 2003, the number of rail containers entering the United States grew faster (14 percent) than the incoming truck containers (5 percent). Most of the growth was in incoming rail containers from Canada (table 7).

Water Freight Gateways

In 2003, over two-thirds (68 percent) of the value of U.S. international merchandise trade passing through U.S. freight gateways was to and from countries other than Canada and Mexico and was worth about $1.4 trillion (table 4). Since 1990, the value of this U.S. overseas8 trade has more than doubled, rising at an average annual rate of 6 percent per year (table 4). Maritime trade accounted for about 60 percent of this trade; air freight accounted for the rest.9

U.S. maritime trade passing through our seaports rose from $434 billion in 1990 to $811 billion in 2003 at about a 5 percent annual rate (table 5). This robust growth in U.S. overseas trade highlights the rising importance of China, which now ranks as our second largest provider of merchandise imports by value of shipments.10 The growth also underscores the continued expansion of trade with several Pacific Rim nations and the rise of the Port of Los Angeles as the nation’s top freight gateway by value in 2003. While cargo passing through our seaports in 2003 accounted for the largest modal share (41 percent) of the value of overall U.S. merchandise trade, this share declined from 49 percent in 1990 as land and air trade’s share increased (figure 3).

The Port of Los Angeles’ prominence as a top gateway by value of goods reflects the specialization among U.S. seaports. The Pacific and Atlantic coast ports are heavily involved in container trade, while the U.S. Gulf Coast ports are primarily involved in dry bulk and tanker trade. Gulf ports such as Houston, Texas, lead other U.S. ports in terms of tonnage of international cargo shipments—agricultural, petroleum, coal, and other bulk commodities. In general, bulk commodities are lower value per ton, and containerized commodities are higher value per ton.

Over 1.2 billion short tons of international maritime cargo was transported through U.S. seaports in 2003, with exports accounting for 30 percent and imports accounting for 70 percent of that tonnage. Table 8 shows that the list of the largest seaports changes when ranked by tonnage rather than by cargo value. In 2003, the top three seaport gateways by weight were the Port of Houston (over 126 million tons of freight), followed by the Port of South Louisiana (80 million tons) and the Port of New York and New Jersey (78 million tons). The top 20 seaports accounted for 64 percent of the maritime export tonnage and 72 percent of the import tonnage.

Air Freight Gateways

In 2003, air freight accounted for 26 percent ($523 billion) of the total U.S. merchandise trade of nearly $2 trillion, up from 23 percent in 1990 (figure 3). Between 1990 and 2003, the value of inbound and outbound air cargo handled at the U.S. gateway airports grew at an average annual rate of about 8 percent (table 5).

John F. Kennedy (JFK) International Airport in New York was the leading U.S. airport for international freight by value in 2003, handling over one-fifth (21 percent) of U.S. air imports and exports, valued at $112 billion. JFK Airport also was the leading overall gateway by value until 2003, when it was overtaken by the maritime Port of Los Angeles because of huge growth in U.S.-Asia trade.

Over 8 million tons of international air freight was moved on nonstop international air segments through all the U.S. air gateways in 2003. Anchorage was the nation’s leading air gateway by weight, handling 26 percent of the total international airfreight tonnage. Because the types of commodities transported by air are higher in value per ton (e.g., cut flowers, electronics, and clothing) than those transported by other freight modes, the value of shipments is a much better indicator than weight in revealing the importance of air gateways to the nation’s international commerce.

The Gateways and Data Needs

Research and analysis needed to aid effective transportation decisionmaking is hampered by the lack of complete data on U.S. international freight. No single data source provides all the data needed for international transportation research (see box 2). Fully understanding trends in the movement of goods and having reliable forecasts for transportation decisionmaking requires consistent and comparable data on both the weight and the value of internationally traded goods. The lack of weight data for land exports is a problem for transportation freight analysis. Shipment weight data are currently not collected for exports transported by truck, rail, and pipeline. The International Trade Data System (ITDS), a federal information technology initiative led by the U.S. Customs and Border Protection, is expected to meet this need, providing not only the weight information by mode of transportation but also better origin and destination data. The ITDS is expected to be fully operational in 2010.11

Another data gap for international freight transportation analysis is the lack of outbound border crossing information from official U.S. government sources. Data are only collected for incoming trucks and trains and the containers they carry. This data gap limits analysis of the level of transportation activity at the land border gateways regarding capacity needs, congestion management, traffic delays, and safety.

1 In inflation-adjusted terms, U.S. international trade grew from $837 billion to $2 trillion (in chained 2000 dollars).

2 This report uses the value of traded goods instead of the weight of traded goods to rank the leading freight gateways, because weight data for land exports are not collected by U.S. authorities (see box 1). Hence, this report does not cite weight data for land exports at individual gateways. However, BTS has estimated the weight of land exports at the national level based on value-to-weight ratios from the import data and this is presented in figure 2. Additional information on U.S. trade data is presented in box 2.

3 Maritime vessels accounted for about 6 percent and air cargo 5 percent.

4 Official figures are unavailable by tonnage because weight data for surface exports are not collected by U.S. authorities.

5 Kansas City Southern (KCS). 2002. The NAFTA Railway. Available at as of October 2004. The primary partners of NAFTA Railway are Kansas City Southern Railway (KCSR), Texas Mexican Railway (Tex Mex), Grupo Transportacion Ferroviaria Mexicana (TFM) and Panama Canal Railway Co. (PCRC).

6 As mentioned in box 1, weight data for land modes are only available for imports; BTS has estimated the weight of land exports at the national level based on value-to-weight ratios from import data.

7 These figures represent the number of incoming crossings and not the number of unique individual vehicles. They include both loaded and unloaded commercial trucks. For example, if a truck crosses the border multiple times in one day, each incoming crossing is counted. Official data for outgoing trucks, trains, and containers for all land border crossing ports are not collected by U.S. government agencies. Some State Departments of Transportation (e.g., Texas) and Metropolitan Planning Organizations (e.g., Whartcom County in Washington State) collect outgoing crossings data for border ports in their areas.

8 Canada remains the top overall partner for total imports and exports followed by Mexico.

9 For comparison purposes U.S.-NAFTA maritime and air trade are excluded from these statistics. In 2003, U.S. maritime trade with Canada and Mexico was $38 billion; U.S. air trade was $28 billion.

10 Canada remains the top overall partner for total imports and exports, followed by Mexico.

11 Additional information on the ITDS is available at