The change in the carrying amount of goodwill by segment is as follows:


In millions	Freight Segment		Transit Segment		Total
Balance at December 31, 2024	$	7,248	$	1,462	$	8,710
Additions/adjustments	14		—		14
Foreign currency impact	29		183		212
Balance at June 30, 2025	$	7,291	$	1,645	$	8,936

As of June 30, 2025 and December 31, 2024, the Company’s trade names had a net carrying amount of $646 million and $595 million, respectively. The Company believes these intangibles have indefinite lives, with the exception of the right to use the GE Transportation trade name, to which the Company had assigned a useful life of 5 years and became fully amortized in the first quarter of 2024.


	June 30, 2025						December 31, 2024
In millions	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount
Backlog	$	1,310	$	(568)	$	742	$	1,415	$	(629)	$	786
Customer relationships	1,379		(532)		847		1,329		(480)		849
Acquired technology	1,321		(667)		654		1,318		(614)		704
Total	$	4,010	$	(1,767)	$	2,243	$	4,062	$	(1,723)	$	2,339

At June 30, 2025, the weighted average remaining useful lives of backlog, customer relationships and acquired technology were 9 years, 14 years and 6 years, respectively. The backlog intangible asset primarily consists of in-place long-term service agreements acquired by the Company in conjunction with the acquisition of GE Transportation. Amortization expense for intangible assets was $69 million and $142 million for the three and six months ended June 30, 2025, respectively, and $71 million and $145 million for the three and six months ended June 30, 2024, respectively.

Amortization expense for the five succeeding years is estimated to be as follows:


In millions
Remainder of 2025	$	137
2026	$	272
2027	$	268
2028	$	266
2029	$	264