The Indiana Harbor Belt Railroad is the largest switch carrier in the U.S. with 54 miles of mainline track (24 miles of which is double main track) and 266 miles of additional yard and siding track.

The IHB provides a wide variety of services, including industrial switching with 160 customers, generating 170,000 carloads of business annually. The IHB interchanges daily with 16 other rail carriers in Chicago. A growing fleet of approximately 1,400 freight cars is geared predominately to the steel industry. The industrial traffic base includes 4 of the 5 largest steel producers in the U.S. and a large aluminum processor, oil refineries, corn millers, grain elevators, chemical plants, warehouses, lumber transloading, and bulk transfer operations. IHB's industrial traffic consists of 38% primary metals, 12% chemicals & petroleum products, 11% food products, 8% scrap iron, 7% coal & coke, 6% whole grain, as well as a variety of other products including lumber, paper, and aggregates. The IHB also operates as an intermediate switch carrier between the 12 trunk-line railroads for traffic interchanged between them in Chicago, generating an additional 475,000 revenue cars.

The IHB circles Chicago from near O'Hare to Northwest Indiana and roughly parallels Interstate 294 (Tri-state Expressway) and I-80/94. Along this route are IHB yards: Blue Island (a 44 class track hump yard) at Riverdale, IL; Gibson (in Hammond, IN) which classifies cars of new autos; and Michigan Avenue Yard (in East Chicago, Indiana) servicing extensive steel plants. The IHB’s diversified portfolio of business includes steel, autos, and oil related commodities. From East Chicago, Indiana, the IHB operates east for an additional 16 miles on trackage rights to access Burns Harbor, IN and Portage, IN, which includes Indiana's International Port.