Properties (Tables)

12 Months Ended

Dec. 31, 2011

Properties Tables [Abstract]

Properties [Table Text Block]

The following tables list the major categories of property and equipment, as well as the weighted-average composite depreciation rate for each category:

Millions, Except Percentages			Accumulated		Net Book		Depreciation
As of December 31, 2011	Cost		Depreciation		Value		Rate for 2011
Land	$	5,098	$	N/A	$	5,098	N/A
Road:
Rail and other track material [a]		12,461		4,592		7,869	3.3%
Ties		7,987		2,028		5,959	2.9%
Ballast		4,178		1,008		3,170	3.0%
Other [b]		14,118		2,502		11,616	2.6%
Total road		38,744		10,130		28,614	2.9%
Equipment:
Locomotives		6,502		3,003		3,499	5.7%
Freight cars		1,957		1,061		896	3.5%
Work equipment and other		529		57		472	6.5%
Total equipment		8,988		4,121		4,867	5.3%
Technology and other		610		259		351	12.3%
Construction in progress		1,004		-		1,004	N/A
Total	$	54,444	$	14,510	$	39,934	N/A

Millions, Except Percentages				Accumulated		Net Book		Depreciation
As of December 31, 2010		Cost		Depreciation		Value		Rate for 2010
Land		$	4,984	$	N/A	$	4,984	N/A
Road:
Rail and other track material [a]			11,992		4,458		7,534	3.1%
Ties			7,631		1,858		5,773	2.8%
Ballast			4,011		944		3,067	3.0%
Other [b]			13,634		2,376		11,258	2.5%
Total road			37,268		9,636		27,632	2.8%
Equipment:
Locomotives			6,136		2,699		3,437	5.6%
Freight cars			1,886		1,040		846	3.6%
Work equipment and other			305		39		266	4.0%
Total equipment			8,327		3,778		4,549	5.1%
Technology and other			565		241		324	13.2%
Construction in progress			764		-		764	N/A
Total		$	51,908	$	13,655	$	38,253	N/A
[a]	Includes a weighted-average composite depreciation rate for rail in high-density traffic corridors as discussed below.
[b]	Other includes grading, bridges and tunnels, signals, buildings, and other road assets.