Construction aggregates — like crushed stone, sand and gravel — are found in nearly every state in the nation, making long distance shipments of these materials unnecessary.
As a result, freight trains, which typically specialize in long-haul movement of freight, may seem like an unlikely transportation partner. However, over the past decade, efficiency enhancements and investments have allowed railroads to become serious players in the movement of rock. And because one railcar can carry as much aggregate as four truck-trailers, freight rail is an environmentally friendly way to move aggregates.
In 2018, freight railroads moved 1.5 million carloads of sand, stone and gravel.
Aggregates are used in virtually every construction project, from roads to runways to buildings and sewer systems. Analysts estimate that that approximately 80% of U.S. crushed stone is used as a construction material, mainly for road construction, while 43% of U.S. sand and gravel is used for concrete aggregates.
Freight railroads transport raw materials such as crushed stone, limestone, sand, gravel and gypsum from quarries or suppliers to cement and ready-mix concrete plants where cement and clay products materials such as brick and concrete are produced. These materials are then transported to construction distribution centers and construction sites where they serve a wide range of purposes, from cement used in building foundations to Gypsum used in wallboard production and clay-base ceramic tile used in floors and walls.
Texas is the largest producer and consumer of aggregates among the 50 states. In fact, Texas’ growing population — particularly around Houston and Dallas, Ft. Worth — has driven the most demand for aggregates shipped by freight rail.