CSX CORP

When used in this report, unless otherwise indicated by the context, these terms are used to mean the following:

Car hire - A charge paid by one railroad for its use of cars belonging to another railroad or car owner.

Class I freight railroad - One of the largest line haul freight railroads as determined based on operating revenue; the exact revenue required to be in each class is periodically adjusted for inflation by the Surface Transportation Board. Smaller railroads are classified as Class II or Class III.

Common carrier mandate - A federal mandate that requires U.S. railroads to accommodate reasonable requests from shippers to carry any freight, including hazardous materials.

Demurrage - A charge assessed by railroads for the use of rail cars by shippers or receivers of freight beyond a specified free time.

Department of Transportation ("DOT") - A U.S. government agency with jurisdiction over matters of all modes of transportation.

Depreciation study - Conducted by a third-party specialist and analyzed by management, a periodic statistical analysis of fixed asset service lives, salvage values, accumulated depreciation, and other factors for group assets along with a comparison of similar asset groups at other companies.

Double-stack - Stacking containers two-high on specially equipped cars.

Economic Profit (CSX Cash Earnings or CCE)- A non-GAAP measure designed to incentivize strategic investments earning more than the required return. Economic Profit is calculated as CSX’s gross cash earnings (after-tax adjusted EBITDA) minus the capital charge (long-term average cost of capital) on gross operating assets.

Environmental Protection Agency (“EPA”) - A U.S. government agency that has regulatory authority with respect to environmental law.

Federal Railroad Administration ("FRA") - The branch of the DOT that is responsible for developing and enforcing railroad safety regulations, including safety standards for rail infrastructure and equipment.

Free cash flow ("FCF") - The calculation of a non-GAAP measure by using net cash provided by operating activities and adjusting for property additions and certain other investing activities. Free cash flow is a measure of cash available for paying dividends, share repurchases and principal reduction on outstanding debt.

Group-life depreciation- A type of depreciation in which assets with similar useful lives and characteristics are aggregated into groups. Instead of calculating depreciation for individual assets, depreciation is calculated as a whole for each group.

Incidental charges - Charges for switching, demurrage, storage, etc.

Intermodal - A flexible way of transporting freight over highway, rail and water without being removed from the original transportation equipment, namely a container or trailer.

CSX 2024 Form 10-K p.26

Mainline - The main track thoroughfare, exclusive of terminals, yards, sidings and turnouts.

Pipeline and Hazardous Materials Safety Administration (“PHMSA”) - An agency within the DOT that, together with the FRA, has broad jurisdiction over railroad operating standards and practices, including hazardous materials requirements.

Positive Train Control ("PTC")- An interoperable train control system designed to prevent train-to-train collisions, over-speed derailments, incursions into established work-zone limits, and train diversions onto another set of tracks.

Revenue adequacy - The achievement of a rate of return on investment over time at least equal to the industry cost of investment capital, as measured by the STB.

Shipper - A customer shipping freight via rail.

Siding - Track adjacent to the mainline used for passing trains.

Staggers Act of 1980 - Congressional law that significantly deregulated the rail industry, replacing the regulatory structure in existence since the 1887 Interstate Commerce Act. Where previously rates were controlled by the Interstate Commerce Commission, the Staggers Act allowed railroads to establish their own rates for shipments, enhancing their ability to compete with other modes of transportation.

Surface Transportation Board ("STB") - An independent governmental adjudicatory body administratively housed within the DOT, responsible for the economic regulation of interstate surface transportation within the United States.

Switching - Putting cars in a specific order, placing cars for loading, retrieving empty cars or adding or removing cars from a train at an intermediate point.

Terminal - A facility, typically owned by a railroad, for the handling of freight and for the breaking up, making up, forwarding and servicing of trains.

Transportation Security Administration (“TSA”) - A component of the Department of Homeland Security with broad authority over railroad operating practices that may have homeland security implications.

TTX Company ("TTX") - A company that provides its owner-railroads with standardized fleets of intermodal, automotive and general use railcars at time and mileage rates. CSX owns about 20 percent of TTX's common stock, and the remainder is owned by the other leading North American railroads and their affiliates.

Turnout - A track that diverts trains from one track to another.

Yard - A system of tracks, other than main tracks and sidings, used for making up trains, storing cars and other purposes.

CSX 2024 Form 10-K p.27