Properties (Tables)

12 Months Ended

Dec. 31, 2020

The following tables list the major categories of property and equipment as well as the weighted-average estimated useful life for each category (in years):



Millions, Except Estimated Useful Life			Accumulated		Net Book		Estimated
As of December 31, 2020	Cost		Depreciation		Value		Useful Life
Land	$	5,246	$	N/A	$	5,246	N/A
Road:
Rail and other track material		17,620		6,631		10,989	42
Ties		11,051		3,331		7,720	34
Ballast		5,926		1,753		4,173	34
Other roadway [a]		21,030		4,329		16,701	48
Total road		55,627		16,044		39,583	N/A
Equipment:
Locomotives		9,375		3,555		5,820	17
Freight cars		2,118		789		1,329	25
Work equipment and other		1,107		351		756	18
Total equipment		12,600		4,695		7,905	N/A
Technology and other		1,199		520		679	13
Construction in progress		748		-		748	N/A
Total	$	75,420	$	21,259	$	54,161	N/A



Millions, Except Estimated Useful Life			Accumulated		Net Book		Estimated
As of December 31, 2019	Cost		Depreciation		Value		Useful Life
Land	$	5,276	$	N/A	$	5,276	N/A
Road:
Rail and other track material		17,178		6,381		10,797	42
Ties		10,693		3,186		7,507	34
Ballast		5,752		1,669		4,083	34
Other roadway [a]		20,331		4,056		16,275	48
Total road		53,954		15,292		38,662	N/A
Equipment:
Locomotives		9,467		3,434		6,033	18
Freight cars		2,083		779		1,304	25
Work equipment and other		1,081		322		759	18
Total equipment		12,631		4,535		8,096	N/A
Technology and other		1,136		503		633	12
Construction in progress		1,249		-		1,249	N/A
Total	$	74,246	$	20,330	$	53,916	N/A

[a]Other roadway includes grading, bridges and tunnels, signals, buildings, and other road assets.