Minimum annual capital and operating lease payments, as of December 31, 2018, under non-cancelable leases, principally for chassis, other equipment and real estate, as well as other commitments are payable as follows (in thousands):

				Operating
				Leases and
	Capital			Other
	Lease			Commitments		Total
2019	$	3,091		$	14,942	$	18,033
2020		3,099			11,879		14,978
2021		1,795			9,308		11,103
2022		-			8,350		8,350
2023		-			6,770		6,770
2024 and thereafter		-			9,831		9,831
	$	7,985		$	61,080	$	69,065
Less: Imputed interest		(401	)
Net capital lease liability	$	7,584

Total rental expense included in general and administrative expense, which relates primarily to real estate, was approximately $10.6 million in 2018, $9.5 million in 2017 and $8.1 million in 2016. Many of the real estate leases contain renewal options and escalation clauses which require payments of additional rent to the extent of increases in the related operating costs. We straight-line rental expense in accordance with the FASB guidance in the Leases Topic of the Codification.

We incur rental expense for our leased containers, tractors and trailers that are included in transportation costs and totaled $10.7 million, $6.0 million, and $3.6 million for 2018, 2017 and 2016, respectively.

We incur user charges for use of a fleet of rail owned chassis, chassis under capital lease and dedicated rail owned containers on the Union Pacific and Norfolk Southern railroads which are included in transportation costs. Such charges were $80.4 million, $77.6 million and $73.7 million for 2018, 2017 and 2016, respectively. We have the ability to return the majority of the containers and pay for the rail owned chassis only when we are using them under these agreements. As a result, no minimum commitments related to these rail owned chassis and containers have been included in the table above.

In February 2016, the FASB issued ASU No. 2016-02, Leases, which requires lessees to recognize a right-of-use asset (“ROU”) and a lease obligation for all leases. We adopted the standard as of January 1, 2019, as required.

We anticipate the adoption of this standard will result in the recognition of approximately $29 million to $37 million of ROU assets and liabilities on our consolidated balance sheet. The lease liabilities to be recognized will be measured based upon the present value of minimum future payments and the ROU assets to be recognized will be equal to lease liabilities, adjusted for prepaid and accrued rent balances which are recorded in the Consolidated Balance Sheets as of December 31, 2018.

Hub currently does not have any variable lease payments that depend on an index or a rate (such as the Consumer Price Index or a market interest rate). Additionally, some leases have options to extend or terminate, which Management will determine if exercised or not. If any of the options are exercised, this will be reflected in the ROU asset and lease liability accordingly. As of January 1, 2019, the ROU asset and lease liabilities do not reflect any options to extend or terminate any of the leases as management is not reasonably certain it will exercise any of these options. Also, current leases do not contain any restrictions or covenants imposed by the leases or residual value guarantees.

Occasionally, Hub will sublease office space or parking spaces. The subleases do not relieve Hub of any of its primary obligations under the original agreement. Currently, Hub has subleases with an expected annual income totaling $0.5 million.

Subsequent to January 1, 2019, Hub signed property lease contracts which have not commenced yet but that creates significant rights and obligations for Hub. Based on the present value of the lease payments, the estimated ROU assets and lease liabilities related to this contract will total approximately $6.7 million.