The transportation category includes vehicles and equipment used to transport people and products (i.e., automobiles, ships, aircraft, etc.). The study shows the annual cost of corrosion in the transporation category is $29.7 billion, which is 21.5% of the total cost of the sector categories examined in this study. The transportation category is divided into five industry sectors: motor vehicles, ships, aircraft, railroad cars, and hazardous materials transport.

Motor Vehicles

There are over 200 million registered vehicles in the U.S. Assuming an average value of $5,000, the total investment Americans have made in vehicles can be estimated at more than $1 trillion. Until the late 1950s, corrosion of motor vehicles was limited to marine environments; however, with the increased use of de-icing salts, vehicles in the snowbelt regions began to corrode and literally fell apart within a few years after purchase. In the late 1970s, automobile manufacturers started to increase the corrosion resistance of vehicles by using corrosion resistant materials, employing better manufacturing processes, and by designing more corrosion resistant vehicles through corrosion engineering knowledge. Because of the steps taken by the manufacturers, today’s automobiles have very little visible corrosion and most vehicles survive structurally until the vehicle wears out mechanically. The total annual cost incurred however, is high and much can be done to further reduce the cost.

The total cost of corrosion for motor vehicles is estimated at $23.4 billion per year or 79% of the transportation category. This cost is divided into the following three components: 1) increased manufacturing costs due to corrosion engineering and the use of corrosion-resistant materials ($2.56 billion per year), 2) repairs and maintenance necessitated by corrosion ($6.45 billion per year), and 3) corrosion-related depreciation of the vehicles ($14.46 billion per year).

Ships

Most ships that serve U.S. ports do not sail under U.S. flag, but under that of nations with less restrictive laws and taxation; therefore, it is difficult to estimate the national cost of corrosion for this sector. That being said, the U.S. flag fleet consists of: Great Lakes with 737 vessels at 62 billion ton-miles, inland with 33,668 vessels at 294 billion ton-miles, ocean with 7,014 vessels at 350 billion ton-miles, recreational with 12.3 million boats, and cruise ship with 122 boats serving North American ports (5.4 million passengers). The total annual direct cost of corrosion to the U.S. shipping industry is estimated at $2.7 billion. This cost is divided into costs associated with new ship construction ($1.1 billion), with maintenance and repairs ($0.8 billion), and with corrosion-related downtime ($0.8 billion).

Aircraft

In 1998, the combined commercial aircraft fleet operated by airlines in the U.S. was over 7,000 airplanes. At the start of the jet age (1950s to 1960s), little or no attention was paid to corrosion and corrosion control. One of the concerns is the continued aging of the airplanes beyond the 20-year design life. Only the most recent designs (e.g. Boeing 777 and late version 737) have incorporated significant improvements in corrosion prevention and control in design and manufacturing. The total annual direct cost of corrosion to the U.S. aircraft industry is estimated at $2.2 billion, which includes the cost of design and manufacturing ($0.2 billion), corrosion maintenance ($1.7 billion), and downtime ($0.3 billion).

Railroad Cars

In 1998, 1.3 million freight cars and 1,962 passenger cars were operating in the United States. The type of commodities transported range from coal (largest volume) to chemicals, motor vehicles, farm products, food products, ores and minerals. Railroad cars suffer from both external and internal corrosion. The total annual direct cost of corrosion is estimated to be $0.5 billion, divided over external coatings ($0.25 billion) and internal coatings and linings ($0.25 billion).

Hazardous Materials Transportation

Each year, close to 2 billion tons of hazardous materials are produced in the United States. The amount of hazardous materials shipments that are shipped each year is approximately three billion tons. Each shipment will be moved several times before reaching its destination. Bulk transportation of hazardous materials includes overland shipping by tanker truck and rail tank car, and by special containers that are loaded onto vehicles. Over water, ships loaded with specialized containers, tanks, and drums are used. The total cost of corrosion for hazardous materials transportation is at least $0.887 billion per year. The elements of this cost include the corrosion-related cost of transport vehicles ($400 million per year), the cost of specialized packaging ($487 million per year), and the direct cost of $0.5 million per year of accidental releases and other corrosion-related transportation incidents. The indirect costs of releases are not known.