The current economic downturn must not be allowed to obscure the fact that the nation needs more transportation capacity, and needs it now. Our economy will not grow if goods and people aren’t able to effectively and efficiently move from one section of the country to another. Yet highways are packed today, with congestion already costing the country more than $80 billion annually, according to the Texas Transportation Institute.

[IMGCAP(1)]Meanwhile, there is a growing consensus that much more needs to be done to clean up the environment. But depending largely on highways to meet the country’s growing transportation needs will make it far more difficult to meet environmental goals.

One way to solve this seeming contradiction is to expand both passenger and freight rail. We welcome the commitment of the Obama administration in its pursuit of high-speed passenger rail as a way to improve mobility while at the same time reducing pollution and conserving energy.

Freight railroads already make substantial contributions in all three areas — and they can make even more, so long as there is sufficient capacity to meet the nation’s growing transportation needs.

Freight trains relieve congestion and improve mobility. A single intermodal train can remove 280 trucks from the highways. That’s the equivalent of removing 1,100 automobiles. It would take 500 trucks to move as much freight as a single-unit train carrying bulk commodities such as coal and lumber. That’s the equivalent of removing almost 2,000 autos.

Intermodal trains are especially effective in reducing congestion from already crowded roads and highways. Working with trucking companies, ocean steamship lines and logistics companies, railroads move containers and truck trailers over long distances while cooperating with motor carriers to provide short haul pickup and delivery service. Last year, rail intermodal service took nearly 12 million trucks off the highways — the equivalent of about 45 million automobiles.

Freight trains also reduce pollution. The Environmental Protection Agency says locomotives are on average three times cleaner than trucks. Greenhouse gas emissions would fall by 12 million tons annually if just 10 percent of the long-haul freight moving on the highways instead moved by rail. New technology is making locomotives even cleaner, reducing idling, improving fuel mileage and reducing harmful emissions.

And freight trains conserve energy. In 2008, freight trains were able to move a ton of freight an average of 457 miles on a gallon of diesel fuel, more than three times as far as a truck can move it. Just since 1980, railroads have improved their fuel efficiency by 80 percent. If just 10 percent of long-haul truck tonnage moved instead by rail, the nation could save more than 1 billion gallons of fuel annually.

Railroads are increasing capacity, yet they are limited in what they can prudently invest to accomplish that. Unlike highways, which are publicly owned and funded, railroads are privately owned and don’t receive public funds to build and grow their network infrastructure and increase rail capacity. They provide the full cost of their infrastructure and its maintenance.

If our society is to become increasingly mobile, policymakers need to look closely at what they can do to encourage expansion of rail capacity to meet future growth challenges.

One idea is to provide tax credits for investments that expand rail capacity and allowing rail to depreciate all capital improvements in the year they are made. This would make it economically feasible to invest in more projects where the return otherwise would be inadequate. Bipartisan legislation to accomplish that has been introduced by Reps. Kendrick Meek (D-Fla.) and Eric Cantor (R-Va.) in the House, where it has gained a wide range of supporters.

Another way to encourage new funding is public-private partnerships, where the public pays for public benefits and the railroad pays for the benefits it receives. One example of this is the Chicago CREATE program — a public-private partnership that includes construction of a number new overpasses or underpasses where roads cross railroad tracks to reduce highway congestion, air pollution and grade crossing accidents. The program also includes streamlining Chicago’s rail network to benefit both passenger and freight services.

America’s growing congestion must be addressed to foster the nation’s continued economic growth. There is no one solution to the problem, but most assuredly rail has is a part of the solution. Public-private partnerships and a relatively modest program of tax incentives are just two approaches worth considering.

Edward R. Hamberger is president and CEO of the Association of American Railroads.