Operations and Segmentation – We are a Class I railroad operating in the U.S. Our network includes 32,340 route miles, linking Pacific Coast and Gulf Coast ports with the Midwest and Eastern U.S. gateways and providing several corridors to key Mexican gateways. We own 26,094 miles and operate on the remainder pursuant to trackage rights or leases. We serve the western two-thirds of the country and maintain coordinated schedules with other rail carriers for the handling of freight to and from the Atlantic Coast, the Pacific Coast, the Southeast, the Southwest, Canada, and Mexico. Export and import traffic is moved through Gulf Coast and Pacific Coast ports and across the Mexican and Canadian borders.

The Railroad, along with its subsidiaries and rail affiliates, is our one reportable operating segment. Although we provide and analyze revenue by commodity group, we treat the financial results of the Railroad as one segment due to the integrated nature of our rail network. Our operating revenues are primarily derived from contracts with customers for the transportation of freight from origin to destination. The following table represents a disaggregation of our freight and other revenues:



Millions	2019		2018		2017
Agricultural Products	$	4,444	$	4,469	$	4,303
Energy		3,761		4,608		4,498
Industrial		5,796		5,679		5,204
Premium		6,242		6,628		5,832
Total freight revenues	$	20,243	$	21,384	$	19,837
Other subsidiary revenues		880		881		885
Accessorial revenues		514		502		458
Other		71		65		60
Total operating revenues	$	21,708	$	22,832	$	21,240

Although our revenues are principally derived from customers domiciled in the U.S., the ultimate points of origination or destination for some products we transport are outside the U.S. Each of our commodity groups includes revenue from shipments to and from Mexico. Included in the above table are freight revenues from our Mexico business which amounted to $2.3 billion in 2019, $2.5 billion in 2018, and $2.3 billion in 2017.

Basis of Presentation – The Consolidated Financial Statements are presented in accordance with accounting principles generally accepted in the U.S. (GAAP) as codified in the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC).