(4) Allowance for Probable Loan Losses

The allowance for probable loan losses primarily consists of the aggregate loan loss allowances of the bank subsidiaries. The allowances are established through charges to operations in the form of provisions for probable loan losses. Loan losses or recoveries are charged or credited directly to the allowances. The allowance for probable loan losses of each bank subsidiary is maintained at a level considered appropriate by management, based on estimated probable losses in the loan portfolio. The allowance for probable loan losses is derived from the following elements: (i) allowances established on specific impaired loans, which are based on a review of the individual characteristics of each loan, including the customer’s ability to repay the loan, the underlying collateral values, and the industry in which the customer operates, (ii) allowances based on actual historical loss experience for similar types of loans in the Company’s loan portfolio, and (iii) allowances based on general economic conditions, changes in the mix of loans, company resources, border risk and credit quality indicators, among other things.

The Company’s management continually reviews the allowance for loan losses of the bank subsidiaries using the amounts determined from the allowances established on specific impaired loans, the allowance established on quantitative historical loss percentages, and the allowance based on qualitative data to establish an appropriate amount to maintain in the Company’s allowance for loan losses. Should any of the factors considered by management in evaluating the adequacy of the allowance for probable loan losses change, the Company’s estimate of probable loan losses could also change, which could affect the level of future provisions for probable loan losses. While the calculation of the allowance for probable loan losses utilizes management’s best judgment and all information available, the adequacy of the allowance is dependent on a variety of factors beyond the Company’s control, including, among other things, the performance of the entire loan portfolio, the economy, changes in interest rates and the view of regulatory authorities towards loan classifications.

The loan loss provision is determined using the following methods. On a weekly basis, loan past due reports are reviewed by the credit quality committee to determine if a loan has any potential problems and if a loan should be placed on the Company’s internal classified report. Additionally, the Company’s credit department reviews the majority of the Company’s loans for proper internal classification purposes regardless of whether they are past due and segregates any loans with potential problems for further review. The credit department will discuss the potential problem loans with the servicing loan officers to determine any relevant issues that were not discovered in the evaluation. Also, an analysis of loans that is provided through examinations by regulatory authorities is considered in the review process. After the above analysis is completed, the Company will determine if a loan should be placed on an internal classified report because of issues related to the analysis of the credit, credit documents, collateral and/or payment history.

The U.S. economy continues to face uncertainty, with particular attention being paid to continued depressed oil and gas prices, the unprecedented debt and trade deficit of the United States, possible interest rate movement, political changes, the continued impact of overseas markets on the U.S. and the negative impact on US exports and cross border trade between the U.S. and Mexico arising from the strength of the U.S. dollar. Although the Texas and Oklahoma economies continue to perform better than the U.S. economy as a whole, the same issues that are creating uncertainty in the U.S. economy may also negatively impact the economies of Texas and Oklahoma. Economic risk factors are minimized by the underwriting standards of the bank subsidiaries. The general underwriting standards encompass the following principles: (i) the financial strength of the borrower including strong earnings, a high net worth, significant liquidity and an acceptable debt to worth ratio, (ii) managerial and business competence, (iii) the ability to repay, (iv) for a new business, projected cash flows, (v) loan to value, (vi) in the case of a secondary guarantor, a guarantor financial statement, and (vii) financial and/or other character references. Although the underwriting standards reduce the risk of loss, unique risk factors exist in each type of loan in which the bank subsidiaries invest.

Commercial and industrial loans are mostly secured by the collateral pledged by the borrower that is directly related to the business activities of the company such as accounts receivable and inventory. The ability of the borrower to collect accounts receivable, and to turn inventory into sales are risk factors in the repayment of the loan.

Construction and land development loans can carry risk of repayment when projects incur cost overruns, have an increase in the price of building materials, encounter zoning and environmental issues, or encounter other factors that may affect the completion of a project on time and on budget. Additionally, repayment risk may be negatively impacted when the market experiences a deterioration in the value of real estate. Risks specifically related to 1‑4 family development loans also include the practice by the mortgage industry of more restrictive underwriting standards, which inhibits the buyer from obtaining long term financing and excessive housing and lot inventory in the market.

Commercial real estate loans demonstrate a risk of repayment when market values deteriorate, the business experiences turnover in key management, the business has an inability to attract or keep occupancy levels stable, or when the market experiences an exit of a specific business industry that is significant to the local economy, such as a manufacturing plant.

First and second lien residential 1-4 family mortgage and consumer loan repayments may be affected by unemployment or underemployment and deteriorating market values of real estate.

A summary of the changes in the allowance for probable loan losses by loan class is as follows:


	December 31, 2016
	Domestic														Foreign
			Commercial
			real estate:
			other		Commercial
			construction &		real estate:		Commercial
			land		farmland &		real estate:		Residential:		Residential:
	Commercial		development		commercial		multifamily		first lien		junior lien		Consumer		Foreign		Total
	(Dollars in Thousands)
Balance at December 31,	$	21,431	$	13,920	$	19,769	$	1,248	$	3,509	$	5,321	$	638	$	1,152	$	66,988
Losses charge to allowance		(32,959)		(16)		(1,890)		(180)		(70)		(331)		(414)		(41)		(35,901)
Recoveries credited to allowance		7,110		6,099		119		—		21		278		69		19		13,715
Net losses charged to allowance		(25,849)		6,083		(1,771)		(180)		(49)		(53)		(345)		(22)		(22,186)
Provision (credit) charged to operations		30,067		(6,114)		(1,267)		(262)		(1,005)		(1,552)		238		(246)		19,859
Balance at December 31,	$	25,649	$	13,889	$	16,731	$	806	$	2,455	$	3,716	$	531	$	884	$	64,661


	December 31, 2015
	Domestic																					Foreign
				Commercial
				real estate:
				other				Commercial
				construction &				real estate:			Commercial
				land				farmland &			real estate:			Residential:			Residential:
	Commercial				development			commercial			multifamily			first lien			junior lien			Consumer			Foreign			Total
	(Dollars in Thousands)
Balance at December 31,	$	22,352	$			12,955	$		18,683	$		846	$		3,589	$		4,683	$		660	$		1,060	$		64,828
Losses charge to allowance		(24,802)				(695)			(492)			—			(157)			(275)			(704)			—			(27,125)
Recoveries credited to allowance		3,135				141			963			—			30			431			170			10			4,880
Net losses charged to allowance		(21,667)				(554)			471			—			(127)			156			(534)			10			(22,245)
Provision (credit) charged to operations		20,746				1,519			615			402			47			482			512			82			24,405
Balance at December 31,	$	21,431	$			13,920	$		19,769	$		1,248	$		3,509	$		5,321	$		638	$		1,152	$		66,988


	December 31, 2014
	Domestic														Foreign
			Commercial
			real estate:
			other		Commercial
			construction &		real estate:		Commercial
			land		farmland &		real estate:		Residential:		Residential:
	Commercial		development		commercial		multifamily		first lien		junior lien		Consumer		Foreign		Total
	(Dollars in Thousands)
Balance at December 31,	$	22,433	$	12,541	$	24,467	$	776	$	3,812	$	4,249	$	750	$	1,133	$	70,161
Losses charge to allowance		(19,110)		(680)		(1,893)		—		(351)		(661)		(719)		(51)		(23,465)
Recoveries credited to allowance		2,979		72		107		—		49		242		210		50		3,709
Net losses charged to allowance		(16,131)		(608)		(1,786)		—		(302)		(419)		(509)		(1)		(19,756)
Provision (credit) charged to operations		16,050		1,022		(3,998)		70		79		853		419		(72)		14,423
Balance at December 31,	$	22,352	$	12,955	$	18,683	$	846	$	3,589	$	4,683	$	660	$	1,060	$	64,828

The allowance for probable loan losses is a reserve established through a provision for probable loan losses charged to expense, which represents management’s best estimate of probable loan losses when evaluating loans (i) individually or (ii) collectively. The increase in losses charged to the allowance for probable loan losses for the year ended December 31, 2016 can be attributed to further deterioration in a previously identified and charged down relationship primarily secured by multiple pieces of transportation equipment. In March 2016, litigation against the management of the borrower was filed in the State of Nevada, resulting in a going concern issue with the borrower’s operations and the future use of the transportation equipment pledged as collateral on the relationship. As a result, management, in accordance with its credit review procedures, re-evaluated the collateral values on the equipment in light of the new circumstances and reduced the collateral values accordingly, resulting in a further charge-down of the relationship of approximately $19.4 million, which is included in the losses charged to the allowance in the commercial category in the table detailing the year ended December 31, 2016 activity. The impact of the charge-down is also reflected in the various tables in this Note including impaired loans, non-accrual loans and the credit quality indicator summary. The relationship was classified as Watch-List Impaired at December 31, 2015. Two large recoveries on loans charged off in prior years are included in the recoveries credited to the allowance in the table detailing activity for the year ended December 31, 2016. The recoveries occurred in the first and third quarters of 2016 in the amounts of $4.4 million and $6 million, respectively and are included in the Commercial and Commercial Real Estate: Other Construction and Land Development categories. The increase in charge-offs for the years ended December 31, 2015 and 2014 in the Commercial category can be attributed to a charge down of the previously discussed relationship that is primarily secured by multiple pieces of transportation equipment. The relationship was charged down by $13.5 million and $8.5 million for the years ended December 31, 2015 and December 31, 2014, respectively.

The table below provides additional information on the balance of loans individually or collectively evaluated for impairment and their related allowance, by loan class:


	December 31, 2016
	Loans Individually				Loans Collectively
	Evaluated For				Evaluated For
	Impairment				Impairment
	Recorded				Recorded
	Investment		Allowance		Investment		Allowance
	(Dollars in Thousands)
Domestic
Commercial	$	22,412	$	—	$	887,255	$	25,649
Commercial real estate: other construction & land development		4,776		371		1,712,099		13,518
Commercial real estate: farmland & commercial		10,810		546		1,932,260		16,185
Commercial real estate: multifamily		552		—		139,914		806
Residential: first lien		6,836		44		415,068		2,411
Residential: junior lien		978		—		609,340		3,716
Consumer		1,295		—		53,873		531
Foreign		746		—		166,474		884

Total	$	48,405	$	961	$	5,916,283	$	63,700


	December 31, 2015
	Loans Individually				Loans Collectively
	Evaluated For				Evaluated For
	Impairment				Impairment
	Recorded				Recorded
	Investment		Allowance		Investment		Allowance
	(Dollars in Thousands)
Domestic
Commercial	$	30,946	$	1,704	$	935,905	$	19,727
Commercial real estate: other construction & land development		6,221		100		1,643,606		13,820
Commercial real estate: farmland & commercial		13,806		202		1,981,643		19,567
Commercial real estate: multifamily		777		200		138,671		1,048
Residential: first lien		5,699		—		404,545		3,509
Residential: junior lien		950		—		551,388		5,321
Consumer		1,297		—		56,447		638
Foreign		752		—		178,261		1,152

Total	$	60,448	$	2,206	$	5,890,466	$	64,782

Loans accounted for on a non‑accrual basis at December 31, 2016, 2015 and 2014 amounted to $37,245,000, $47,685,000 and $63,559,000, respectively. The effect of such non‑accrual loans reduced interest income by approximately $2,461,800, $3,298,000 and $4,013,000 for the years ended December 31, 2016, 2015 and 2014, respectively. Amounts received on non‑accruals are applied, for financial accounting purposes, first to principal and then to interest after all principal has been collected. Accruing loans contractually past due 90 days or more as to principal or interest payments at December 31, 2016, 2015 and 2014 amounted to approximately $5,226,000, $11,616,000 and $9,988,000, respectively.

The table below provides additional information on loans accounted for on a non‑accrual basis by loan class:


	December 31, 2016		December 31, 2015
	(Dollars in Thousands)
Domestic
Commercial	$	22,369	$	30,894
Commercial real estate: other construction & land development		4,776		3,668
Commercial real estate: farmland & commercial		8,314		11,543
Commercial real estate: multifamily		552		777
Residential: first lien		655		383
Residential: junior lien		166		21
Consumer		26		34
Foreign		387		365
Total non-accrual loans	$	37,245	$	47,685

Impaired loans are those loans where it is probable that all amounts due according to contractual terms of the loan agreement will not be collected. The Company has identified these loans through its normal loan review procedures. Impaired loans are measured based on (1) the present value of expected future cash flows discounted at the loan’s effective interest rate; (2) the loan’s observable market price; or (3) the fair value of the collateral if the loan is collateral dependent. Substantially all of the Company’s impaired loans are measured at the fair value of the collateral. In limited cases the Company may use other methods to determine the level of impairment of a loan if such loan is not collateral dependent.

The following tables detail key information regarding the Company’s impaired loans by loan class for the year ended December 31, 2016:


	December 31, 2016
			Unpaid				Average
	Recorded		Principal		Related		Recorded		Interest
	Investment		Balance		Allowance		Investment		Recognized
	(Dollars in Thousands)
Loans with Related Allowance
Domestic
Commercial real estate: other construction & land development	$	1,958	$	1,971	$	371	$	2,512	$	—
Commercial real estate: farmland & commercial		2,808		3,948		546		3,247		—
Residential: first lien		62		62		44		62		—
Total impaired loans with related allowance	$	4,828	$	5,981	$	961	$	5,821	$	—


	December 31, 2016
			Unpaid		Average
	Recorded		Principal		Recorded		Interest
	Investment		Balance		Investment		Recognized
	(Dollars in Thousands)
Loans with No Related Allowance
Domestic
Commercial	$	21,412	$	50,737	$	19,354	$	3
Commercial real estate: other construction & land development		2,818		4,419		2,336		67
Commercial real estate: farmland & commercial		8,002		9,054		8,523		110
Commercial real estate: multifamily		552		562		401		—
Residential: first lien		6,774		6,847		6,860		298
Residential: junior lien		978		1,017		1,011		52
Consumer		1,295		1,295		1,214		1
Foreign		746		746		751		16
Total impaired loans with no related allowance	$	42,577	$	74,677	$	40,450	$	547

The following tables detail key information regarding the Company’s impaired loans by loan class for the year ended December 31, 2015:


	December 31, 2015
			Unpaid				Average
	Recorded		Principal		Related		Recorded		Interest
	Investment		Balance		Allowance		Investment		Recognized
	(Dollars in Thousands)
Loans with Related Allowance
Domestic
Commercial	$	4,016	$	4,156	$	1,704	$	3,758	$	—
Commercial real estate: other construction & land development		167		169		100		893		—
Commercial real estate: farmland & commercial		4,003		4,309		202		444		92
Commercial real estate: multifamily		599		599		200		599		—
Total impaired loans with related allowance	$	8,785	$	9,233	$	2,206	$	5,694	$	92


	December 31, 2015
			Unpaid		Average
	Recorded		Principal		Recorded		Interest
	Investment		Balance		Investment		Recognized
	(Dollars in Thousands)
Loans with No Related Allowance
Domestic
Commercial	$	26,930	$	38,845	$	30,847	$	4
Commercial real estate: other construction & land development		6,054		6,204		6,455		85
Commercial real estate: farmland & commercial		9,803		10,717		7,258		—
Commercial real estate: multifamily		178		178		205		—
Residential: first lien		5,699		5,822		5,853		264
Residential: junior lien		950		972		1,182		68
Consumer		1,297		1,298		1,227		3
Foreign		752		752		548		17
Total impaired loans with no related allowance	$	51,663	$	64,788	$	53,575	$	441

A portion of the impaired loans have adequate collateral and credit enhancements not requiring a related allowance for loan loss. Management is confident the Company’s loss exposure regarding these credits will be significantly reduced due to the Company’s long‑standing practices that emphasize secured lending with strong collateral positions and guarantor support. Management is likewise confident the reserve for probable loan losses is adequate.

Management of the Company recognizes the risks associated with these impaired loans. However, management's decision to place loans in this category does not necessarily mean that losses will occur. In the current environment, troubled loan management can be protracted because of the legal and process problems that delay the collection of an otherwise collectable loan. Additionally, management believes that the collateral related to these impaired loans and/or the secondary support from guarantors mitigates the potential for losses from impaired loans.

The following table details loans accounted for as “troubled debt restructuring,” segregated by loan class. Loans accounted for as troubled debt restructuring are included in impaired loans.


	December 31, 2016		December 31, 2015
		(Dollars in Thousands)
Domestic
Commercial	$	10,710	$	2,419
Commercial real estate: other construction & land development		—		2,553
Commercial real estate: farmland & commercial		3,086		2,853
Residential: first lien		6,181		5,316
Residential: junior lien		812		929
Consumer		1,269		1,263
Foreign		360		386

Total troubled debt restructuring	$	22,418	$	15,719

The increase in loans accounted for as troubled debt restructurings for December 31, 2016 is due to the renewal of an impaired loan that was previously charged down. The loan is primarily secured by multiple pieces of transportation equipment, as previously discussed with respect to the detail in the changes in the allowance for probable loan losses in this Note. The loan remains on non-accrual status and is included in total impaired loans in the various tables in this Note.

The bank subsidiaries charge off that portion of any loan which management considers to represent a loss, as well as that portion of any other loan which is classified as a “loss” by bank examiners. Commercial and industrial or real estate loans are generally considered by management to represent a loss, in whole or part, when an exposure beyond any collateral coverage is apparent and when no further collection of the loss portion is anticipated based on the borrower’s financial condition and general economic conditions in the borrower’s industry. Generally, unsecured consumer loans are charged‑off when 90 days past due.

While management of the Company considers that it is generally able to identify borrowers with financial problems reasonably early and to monitor credit extended to such borrowers carefully, there is no precise method of predicting loan losses. The determination that a loan is likely to be uncollectible and that it should be wholly or partially charged‑off as a loss is an exercise of judgment. Similarly, the determination of the adequacy of the allowance for probable loan losses can be made only on a subjective basis. It is the judgment of the Company’s management that the allowance for probable loan losses at December 31, 2016 and December 31, 2015, was adequate to absorb probable losses from loans in the portfolio at that date.

The following table presents information regarding the aging of past due loans by loan class:


	December 31, 2016
							90 Days or		Total
	30 - 59		60 - 89		90 Days or		greater &		Past				Total
	Days		Days		Greater		still accruing		Due		Current		Portfolio
	(Dollars in Thousands)
Domestic
Commercial	$	4,081	$	829	$	21,123	$	392	$	26,033	$	883,634	$	909,667
Commercial real estate: other construction & land development		1,502		396		4,456		9		6,354		1,710,521		1,716,875
Commercial real estate: farmland & commercial		3,454		3,054		6,150		289		12,658		1,930,412		1,943,070
Commercial real estate: multifamily		44		—		552		—		596		139,870		140,466
Residential: first lien		5,615		1,350		4,143		3,756		11,108		410,796		421,904
Residential: junior lien		762		178		540		382		1,480		608,838		610,318
Consumer		910		95		413		387		1,418		53,750		55,168
Foreign		931		425		397		11		1,753		165,467		167,220
Total past due loans	$	17,299	$	6,327	$	37,774	$	5,226	$	61,400	$	5,903,288	$	5,964,688


	December 31, 2015
							90 Days or		Total
	30 - 59		60 - 89		90 Days or		greater &		Past				Total
	Days		Days		Greater		still accruing		Due		Current		Portfolio
		(Dollars in Thousands)
Domestic
Commercial	$	3,361	$	940	$	28,615	$	2,566	$	32,916	$	933,936	$	966,852
Commercial real estate: other construction & land development		193		293		3,502		—		3,988		1,645,839		1,649,827
Commercial real estate: farmland & commercial		2,684		1,328		8,292		3,373		12,304		1,983,144		1,995,448
Commercial real estate: multifamily		49		442		826		49		1,317		138,131		139,448
Residential: first lien		5,299		1,545		4,295		4,093		11,139		399,105		410,244
Residential: junior lien		713		413		646		640		1,772		550,566		552,338
Consumer		646		175		487		453		1,308		56,436		57,744
Foreign		2,639		83		807		442		3,529		175,484		179,013
Total past due loans	$	15,584	$	5,219	$	47,470	$	11,616	$	68,273	$	5,882,641	$	5,950,914

The Company’s internal classified report is segregated into the following categories: (i) “Special Review Credits,” (ii) “Watch List—Pass Credits,” or (iii) “Watch List—Substandard Credits.” The loans placed in the “Special Review Credits” category reflect the Company’s opinion that the loans reflect potential weakness which require monitoring on a more frequent basis. The “Special Review Credits” are reviewed and discussed on a regular basis with the credit department and the lending staff to determine if a change in category is warranted. The loans placed in the “Watch List—Pass Credits” category reflect the Company’s opinion that the credit contains weaknesses which represent a greater degree of risk, which warrant “extra attention.” The “Watch List—Pass Credits” are reviewed and discussed on a regular basis with the credit department and the lending staff to determine if a change in category is warranted. The loans placed in the “Watch List—Substandard Credits” classification are considered to be potentially inadequately protected by the current sound worth and debt service capacity of the borrower or of any pledged collateral. These credit obligations, even if apparently protected by collateral value, have shown defined weaknesses related to adverse financial, managerial, economic, market or political conditions which may jeopardize repayment of principal and interest. Furthermore, there is the possibility that some future loss could be sustained by the Company if such weaknesses are not corrected. For loans that are classified as impaired, management evaluates these credits in accordance with the provision of. ASC 310‑10, “Receivables,” and, if deemed necessary, a specific reserve is allocated to the credit. The specific reserve allocated under ASC 310‑10, is based on (i) the present value of expected future cash flows discounted at the loan’s effective interest rate; (ii) the loan’s observable market price; or (iii) the fair value of the collateral if the loan is collateral dependent. Substantially all of the Company’s loans evaluated as impaired under ASC 310‑10 are measured using the fair value of collateral method. In limited cases, the Company may use other methods to determine the specific reserve of a loan under ASC 310‑10 if such loan is not collateral dependent.

The allowance based on historical loss experience on the Company’s remaining loan portfolio, which includes the “Special Review Credits,” “Watch List—Pass Credits,” and “Watch List—Substandard Credits” is determined by segregating the remaining loan portfolio into certain categories such as commercial loans, installment loans, international loans, loan concentrations and overdrafts. Installment loans are then further segregated by number of days past due. A historical loss percentage, adjusted for (i) management’s evaluation of changes in lending policies and procedures, (ii) current economic conditions in the market area served by the Company, (iii) other risk factors, (iv) the effectiveness of the internal loan review function, (v) changes in loan portfolios, and (vi) the composition and concentration of credit volume is applied to each category. Each category is then added together to determine the allowance allocated under ASC 450‑20.

A summary of the loan portfolio by credit quality indicator by loan class is as follows:


			December 31, 2016
			Special		Watch		Watch List—		Watch List—
	Pass		Review		List—Pass		Substandard		Impaired
			(Dollars in Thousands)
Domestic
Commercial	$	720,350	$	90,746	$	1,121	$	75,038	$	22,412
Commercial real estate: other construction & land development		1,648,633		1,986		—		61,480		4,776
Commercial real estate: farmland & commercial		1,792,542		7,983		59,872		71,863		10,810
Commercial real estate: multifamily		139,914		—		—		—		552
Residential: first lien		413,638		814		—		616		6,836
Residential: junior lien		609,190		150		—		—		978
Consumer		53,873		—		—		—		1,295
Foreign		166,474		—		—		—		746
Total	$	5,544,614	$	101,679	$	60,993	$	208,997	$	48,405


			December 31, 2015
			Special		Watch		Watch List—		Watch List—
	Pass		Review		List—Pass		Substandard		Impaired
			(Dollars in Thousands)
Domestic
Commercial	$	771,999	$	42,152	$	31,539	$	90,215	$	30,946
Commercial real estate: other construction & land development		1,582,683		1,164		13,765		45,994		6,221
Commercial real estate: farmland & commercial		1,849,587		2,283		37,765		92,008		13,806
Commercial real estate: multifamily		138,546		—		—		125		777
Residential: first lien		401,053		—		—		3,492		5,699
Residential: junior lien		551,138		—		—		250		950
Consumer		56,440		—		—		7		1,297
Foreign		178,261		—		—		—		752
Total	$	5,529,707	$	45,599	$	83,069	$	232,091	$	60,448

The increase in Special Review credits for December 31, 2016 compared to December 31, 2015 can be attributed to the re-classification of a commercial loan relationship secured mainly by transportation equipment used in the shipping industry to the Pass category. The decrease in Watch-List Pass credits can be attributed to the re-classification of a commercial loan relationship secured mainly by assets, including contract rights of the borrower to the Pass category. Additionally impacting the Watch-List Pass credits in the real estate farmland and commercial category is a reclassification of a relationship secured mainly by warehouses from the Pass category. Also impacting the Watch-List Pass and Watch-List Substandard category at December 31, 2016 is the reclassification of a relationship secured by all assets, equipment, and accounts receivable from Watch-List Substandard to the Pass category. The decrease in Watch-List Impaired loans can be attributed to the charge-down of the loan relationship that is mainly secured by multiple pieces of transportation equipment previously discussed.