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 As of June 30, 2026	Cost		Accumulated depreciation		Net book value		Estimated useful life
Land	$	5,493	N/A		$	5,493	N/A
Road:
Rail and other track material	19,905		8,089		11,816		43
Ties	12,998		4,405		8,593		34
Ballast	6,729		2,375		4,354		34
Other roadway [a]	24,879		6,288		18,591		47
Total road	64,511		21,157		43,354		N/A
Equipment:
Locomotives	10,127		3,817		6,310		17
Freight cars	3,091		1,155		1,936		22
Work equipment and other	1,362		572		790		17
Total equipment	14,580		5,544		9,036		N/A
Technology and other	1,461		724		737		12
Construction in progress	1,579		N/A		1,579		N/A
Total	$	87,624	$	27,425	$	60,199	N/A


Millions, except estimated useful life As of December 31, 2025	Cost		Accumulated depreciation		Net book value		Estimated useful life
Land	$	5,471	N/A		$	5,471	N/A
Road:
Rail and other track material	19,747		7,936		11,811		45
Ties	12,779		4,305		8,474		34
Ballast	6,646		2,309		4,337		34
Other roadway [a]	24,610		6,080		18,530		47
Total road	63,782		20,630		43,152		N/A
Equipment:
Locomotives	9,926		3,813		6,113		18
Freight cars	3,080		1,107		1,973		23
Work equipment and other	1,318		540		778		17
Total equipment	14,324		5,460		8,864		N/A
Technology and other	1,414		669		745		12
Construction in progress	1,413		N/A		1,413		N/A
Total	$	86,404	$	26,759	$	59,645	N/A