Details of the Company’s net properties are as follows:
(Dollars in Millions) AccumulatedNet BookAnnual DepreciationEstimated Useful LifeDepreciation
December 2025CostDepreciationValueRate
(Avg. Years)
Method
Road 
 Rail and Other Track Material$10,318 $(2,311)$8,007 2.5%41Group Life
 Ties7,488 (2,374)5,114 3.5%28Group Life
 Grading3,240 (726)2,514 1.3%75Group Life
 Ballast3,581 (1,183)2,398 2.6%38Group Life
 Bridges, Trestles, and Culverts3,391 (591)2,800 1.7%60Group Life
 Signals and Interlockers3,476 (1,464)2,012 4.1%24Group Life
 Buildings1,577 (580)997 2.5%40
Group Life/ Straight Line (a)
 Other6,197 (2,739)3,458 4.1%25
Group Life/ Straight Line (a)
Total Road39,268 (11,968)27,300   
Equipment      
 Locomotive5,374 (2,267)3,107 3.8%26Group Life
 Freight Cars2,246 (358)1,888 3.1%32Group Life
 Work Equipment and Other3,644 (2,412)1,232 8.9%11
Group Life/ Straight Line (a)
Total Equipment11,264 (5,037)6,227   
Land 2,286 — 2,286 N/AN/AN/A
Construction In Progress998 — 998 N/AN/AN/A
Total Properties$53,816 $(17,005)$36,811    
(a) For depreciation method, certain asset categories contain intermodal terminals, trucking or technology-related assets, which are depreciated using the straight-line method.
NOTE 6.  Properties, continued
(Dollars in Millions) AccumulatedNet BookAnnual DepreciationEstimated Useful LifeDepreciation
December 2024CostDepreciationValueRate(Avg. Years)Method
Road 
 Rail and Other Track Material$9,883 $(2,199)$7,684 2.5%41Group Life
 Ties7,269 (2,252)5,017 3.5%28Group Life
 Grading2,813 (699)2,114 1.3%75Group Life
 Ballast3,494 (1,159)2,335 2.6%38Group Life
 Bridges, Trestles, and Culverts3,234 (572)2,662 1.7%60Group Life
 Signals and Interlockers3,476 (1,480)1,996 4.1%24Group Life
 Buildings1,498 (568)930 2.5%40
Group Life/ Straight Line (a)
 Other6,017 (2,719)3,298 4.1%25
Group Life/ Straight Line (a)
Total Road37,684 (11,648)26,036   
Equipment      
 Locomotive5,252 (2,175)3,077 3.8%26Group Life
 Freight Cars2,311 (407)1,904 3.1%32Group Life
 Work Equipment and Other3,599 (2,303)1,296 8.9%11
Group Life/ Straight Line (a)
Total Equipment11,162 (4,885)6,277   
Land 2,276 — 2,276 N/AN/AN/A
Construction In Progress1,069 — 1,069 N/AN/AN/A
Total Properties$52,191 $(16,533)$35,658    
(a) For depreciation method, certain asset categories contain intermodal terminals, trucking or technology-related assets, which are depreciated using the straight-line method.

About PP&E Disclosures

The PP&E disclosure details a company's physical asset base — land, buildings, machinery, and equipment — along with the depreciation methods and useful life assumptions that determine how these costs flow through the income statement. Capitalization policy thresholds reveal management's judgment on the boundary between expense and asset, directly affecting both reported earnings and asset values.

Key signals: changes in estimated useful lives or depreciation methods can materially shift reported earnings without any operational change. Compare capital expenditures against depreciation expense — when capex consistently trails depreciation, the asset base may be aging and underinvested. Watch for large asset impairments or write-downs that signal overvalued carrying amounts. Asset retirement obligations reveal future environmental or decommissioning costs that are often underappreciated. Compare PP&E intensity (PP&E-to-revenue) against industry peers to assess capital efficiency and competitive positioning.