Properties (Tables)

12 Months Ended

Dec. 31, 2019

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, 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



Millions, Except Estimated Useful Life			Accumulated		Net Book		Estimated
As of December 31, 2018	Cost		Depreciation		Value		Useful Life
Land	$	5,264	$	N/A	$	5,264	N/A
Road:
Rail and other track material		16,785		6,156		10,629	43
Ties		10,409		3,025		7,384	34
Ballast		5,561		1,595		3,966	34
Other roadway [a]		19,584		3,766		15,818	48
Total road		52,339		14,542		37,797	N/A
Equipment:
Locomotives		9,792		3,861		5,931	19
Freight cars		2,229		929		1,300	24
Work equipment and other		1,040		301		739	19
Total equipment		13,061		5,091		7,970	N/A
Technology and other		1,117		493		624	12
Construction in progress		1,024		-		1,024	N/A
Total	$	72,805	$	20,126	$	52,679	N/A

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