Box cars are an aging technology that is still relied upon by many shippers.

Steve Raetz, from the Transportfolio blog, described in depth the situation in his recent post. Here’s a portion of the article:

The story of the disappearing boxcars seems to be one that is best understood through the data and in the eyes of individual shippers and the industries that leverage these assets.
The current boxcar fleet consists of 115,000 cars; 65,276 boxcars will retire over the next 15 years. But new technologies, such as newer boxcars with higher freight capacities, are slowly replacing the older versions.

At the same time, this isn’t an absolute solution; older infrastructure can’t handle the larger freight cars, especially in the northeast.

• Railroads own more than 75% of all boxcars; the average age of these boxcars is close to 30 years. Privately-owned boxcars account for 22% of the market, and boxes have an average age of 19 years. It appears that railroad companies do not foresee a need to increase their ownership or increase their orders for new boxcars in the near future. In fact, they provide incentives and reduced rates to those who use private freight cars instead of using the railroad’s fleet.
• Fewer industries today—especially paper, beer, plywood, and metals—still rely on boxcar use. Products that have traditionally shipped by boxcars are now being moved on newer types of freight cars that are more efficient. Lumber is now shipped on center beam flat cars, which can haul more product per car than boxcar, and are easier to load and unload. Auto manufacturers have moved manufacturing facilities closer to suppliers, making trucks a more economical transportation choice.
• Boxcar fleets are shipping a decreasing number of shipments. In the last 10 years, rail ton-mile shipments have decreased 42% for lumber/wood, 42% for motor vehicles and parts, and 13.2% in pulp and paper. In addition, railroads find boxcars less attractive than unit trains. Boxcars cost $135,000 each, and they have higher dwell times and lower turns than much more profitable unit trains—large trains with similar equipment that go point to point without stopping.

See more here.