Properties

6 Months Ended

Jun. 30, 2021

11. Properties

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 June 30, 2021	Cost		Depreciation		Value		Useful Life
Land	$	5,279	$	N/A	$	5,279	N/A
Road:
Rail and other track material		17,795		6,746		11,049	43
Ties		11,208		3,428		7,780	34
Ballast		5,997		1,808		4,189	34
Other roadway [a]		21,175		4,467		16,708	49
Total road		56,175		16,449		39,726	N/A
Equipment:
Locomotives		9,315		3,674		5,641	17
Freight cars		2,145		806		1,339	25
Work equipment and other		1,117		377		740	18
Total equipment		12,577		4,857		7,720	N/A
Technology and other		1,207		528		679	13
Construction in progress		744		-		744	N/A
Total	$	75,982	$	21,834	$	54,148	N/A



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

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