The components of property and equipment, net as of December 31, 2018 and September 30, 2019 were as follows (in millions):



	As of
	December 31, 2018			September 30, 2019
Land	$	67		$	67
Building and site improvements	93			40
Leasehold improvements	315			349
Computer equipment	858			903
Leased computer equipment	288			484
Leased vehicles	34			26
Internal-use software	51			90
Furniture and fixtures	39			41
Dockless e-bikes	10			72
Construction in progress	832			758
Total	2,587			2,830
Less: Accumulated depreciation and amortization	(946		)	(1,293		)
Property and equipment, net	$	1,641		$	1,537

Depreciation expense relating to property and equipment was $120 million and $294 million for the three and nine months ended September 30, 2018, respectively, and $92 million and $344 million for the three and nine months ended September 30, 2019, respectively.

Amounts in construction in progress represent buildings, leasehold improvements, assets under construction, other assets not placed in service, and build-to-suit leases prior to the adoption of ASC 842 on January 1, 2019. Upon adoption of ASC 842, the Company derecognized build-to-suit assets from construction in progress. Refer to Note 1 - Basis of Presentation and Summary of Significant Accounting Policies for further information.