Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

                The following discussion and analysis of our financial condition and results of operations should be read together with the selected consolidated financial data and our consolidated condensed financial statements and the related notes appearing elsewhere in this report. This discussion and analysis contains forward-looking statements that involve risks, uncertainties and assumptions. Our actual results may differ materially from those anticipated in these forward-looking statements as a result of many factors, including but not limited to those included in our Form 10-K, Part 1, Item 1A for the year ended December 31, 201 4 . We do not assume, and specifically disclaim, any obligation to update any forward-looking statement contained in this report.

Overview

The primary source of our operating revenue is provided by our Truckload segment through a combination of regional short-haul and medium-to-long-haul full-load transportation services. We transport food and other consumer packaged goods that require a temperature-controlled or insulated environment across the United States and into and out of Mexico and Canada.

Our Dedicated segment provides customized transportation solutions tailored to meet individual customers’ requirements, utilizing temperature-controlled trailers, dry vans and other specialized equipment within the United States. Our customer contracts range from three to five years and are subject to annual rate reviews.

Generally, we are paid by the mile for our Truckload and Dedicated services. We also derive Truckload and Dedicated revenue from fuel surcharges, loading and unloading activities, equipment detention and other ancillary services. The main factors that affect our Truckload and Dedicated revenue are the rate per mile we receive from our customers, the percentage of miles for which we are compensated, the number of miles we generate with our equipment and changes in fuel prices. We monitor our revenue production primarily through average Truckload and Dedicated revenue, net of fuel surcharges, per tractor per week. We also analyze our average Truckload and Dedicated revenue, net of fuel surcharges, per total mile, non-revenue miles percentage, the miles per tractor we generate, our fuel surcharge revenue, our accessorial revenue and our other sources of operating revenue.

Our Intermodal segment transports our customers’ freight within the United States primarily utilizing our temperature-controlled trailers and also, through March 2015, our dry containers on railroad flatcars for portions of trips, with the balance of the trips using our tractors or, to a lesser extent, contracted carriers. The main factors that affect our Intermodal revenue are the rate per mile and other charges we receive from our customers.

Our Brokerage segment arranges for smaller third-party carriers to transport freight for our customers in temperature-controlled trailers and dry vans within the United States and into and out of Mexico while we retain the billing, collection and customer management responsibilities. The main factors that affect our Brokerage revenue are the rate per mile and other charges we receive from our customers.

In addition to the factors discussed above, our operating revenue is also affected by, among other things, the United States economy, inventory levels, the level of truck and rail capacity in the transportation market, a contracting driver market, severe weather conditions and specific customer demand.

Our operating revenue decreased $3.0 million, or 0.9%, in the first six months of 2015. Our operating revenue, net of fuel surcharges, increased $21.4 million, or 8.1%, compared with the first six months of 2014. Truckload segment revenue, net of fuel surcharges, decreased 0.8% from the 2014 period. Dedicated segment revenue, net of fuel surcharges, increased 88.1% primarily due to an increase in our average fleet size of 80.5% from the 2014 period. Intermodal segment revenue, net of fuel surcharges, decreased 14.6% due to the disposal in March 2015 of the overhead-intensive containers that were used in our intermodal operations, partially offset by increased volume with our temperature-controlled intermodal trailer service. Brokerage revenue increased 35.0% in the first six months of 2015 due to an increase in volume. Fuel surcharge revenue decreased to $40.2 million in the first six months of 2015 from $64.6 million in the first six months of 2014, which was due to lower fuel prices.

Our profitability is impacted by the variable costs of transporting freight for our customers, fixed costs, and expenses containing both fixed and variable components. The variable costs include fuel expense, driver-related expenses, such as wages, benefits, training, and recruitment, and independent contractor costs, which are recorded under purchased transportation. Expenses that have both fixed and variable components include maintenance and tire expense and our cost of insurance and claims. These expenses generally vary with the miles we travel, but also have a controllable component based on safety, fleet age, efficiency and other factors. Our main fixed costs relate to the acquisition of long-term assets, such as revenue equipment and operating terminals. We expect our annual cost of tractor and trailer ownership will increase in future periods as a result of higher prices of new equipment. Although certain factors affecting our expenses are beyond our control, we monitor them closely and attempt to anticipate changes in these factors in managing our business. For example, fuel prices have significantly fluctuated over the past several years. We manage our exposure to changes in fuel prices primarily through fuel surcharge programs with our customers, as well as through volume fuel purchasing arrangements with national fuel centers and bulk purchases of fuel at our terminals. To help further reduce fuel expense, we have installed and tightly manage the use of auxiliary power units in our tractors to provide climate control and electrical power for our drivers without idling the tractor engine, and also have improved the fuel usage in the temperature-control units on our trailers. For our Intermodal and Brokerage segments, our profitability is impacted by the percentage of revenue we pay to providers for the transportation services we arrange, which is included within purchased transportation in our consolidated condensed statements of operations.

Our operating expenses as a percentage of operating revenue, or “operating ratio,” improved to 90.3% in the first six months of 2015 from 93.4% in the first six months of 2014. Operating expenses as a percentage of operating revenue, with both amounts net of fuel surcharges, improved to 88.9% in the first six months of 2015 from 91.8% in the first six months of 2014. Our operating ratio for the first six months of 2015, net of a gain on the disposition of a facility of $3.7 million, improved to 91.5% and, net of both fuel surcharges and the facility disposition gain, improved to 90.2%. Our net income increased by 40.4% to $18.5 million, or $0.55 per diluted share, in the first six months of 2015 from $13.2 million, or $0.39 per diluted share, in the first six months of 2014. The increase in profitability in the first six months of 2015 was primarily driven by the $0.06 per diluted share impact of the facility disposition gain, the increase in our average Truckload and Dedicated revenue per tractor, the disposal in March 2015 of the overhead-intensive containers that were used in a portion of our intermodal operations, an improvement in net fuel expense with the lower fuel prices, and the impact that the severe weather conditions had on the first quarter of 2014 on both freight volumes and operating costs, partially offset by an increase in insurance and claims.

Our business requires substantial, ongoing capital investments, particularly for new tractors and trailers. At June 30, 2015, we had $4.5 million of cash and cash equivalents, $408.4 million in stockholders’ equity and no long-term debt outstanding. In the first six months of 2015, net cash flows provided by operating activities of $71.8 million were primarily used to purchase new revenue equipment, net of proceeds from dispositions, in the amount of $39.7 million, to repay $24.4 million of long-term debt, to partially construct regional operating facilities in the amount of $4.4 million, and to pay cash dividends of $1.7 million. We estimate that capital expenditures, net of proceeds from dispositions, will be approximately $92 million for the remainder of 2015. We believe our sources of liquidity are adequate to meet our current and anticipated needs for at least the next twelve months. Based upon anticipated cash flows, existing cash and cash equivalents balances, current borrowing availability and other sources of financing we expect to be available to us, we do not anticipate any significant liquidity constraints in the foreseeable future.

              We have transformed our business strategy to a multifaceted set of transportation service solutions, primarily regional Truckload temperature-controlled operations along with Dedicated, Intermodal and Brokerage services, while developing a diverse customer base that gains value from and expands each of these operating segments. We believe that we are well-positioned regardless of the economic environment with this transformation of our services combined with our competitive position, cost control emphasis, modern fleet and strong balance sheet.

This Management’s Discussion and Analysis of Financial Condition and Results of Operations includes discussions of operating revenue, net of fuel surcharge revenue; Truckload, Dedicated and Intermodal revenue, net of fuel surcharge revenue; operating expenses as a percentage of operating revenue, each net of fuel surcharge revenue, the facility disposition gain, and the sum of both amounts; and net fuel expense (fuel and fuel taxes net of fuel surcharge revenue and surcharges passed through to independent contractors, outside drayage carriers and railroads). We provide these additional disclosures because management believes these measures provide a more consistent basis for comparing results of operations from period to period. These financial measures in this report have not been determined in accordance with U.S. generally accepted accounting principles (GAAP). Pursuant to Item 10(e) of Regulation S-K, we have included the amounts necessary to reconcile these non-GAAP financial measures to the most directly comparable GAAP financial measures of operating revenue, operating expenses divided by operating revenue, and fuel and fuel taxes.

C omparison of Three Months Ended June 30, 2015 to Three Months Ended June 30, 2014

The following table sets forth for the periods indicated our operating revenue, operating income and operating ratio by segment, along with the change for each component:

Our operating revenue decreased $4.8 million, or 2.9%, to $163.6 million in the 2015 period from $168.4 million in the 2014 period. Our operating revenue, net of fuel surcharges, increased $8.2 million, or 6.1%, to $143.9 million in the 2015 period from $135.7 million in the 2014 period. This increase was primarily due to a $10.8 million increase in Dedicated revenue, net of fuel surcharges, and a $3.3 million increase in Brokerage revenue, partially offset by a $4.3 million decrease in Intermodal revenue, net of fuel surcharges. Fuel surcharge revenue decreased to $19.7 million in the 2015 period from $32.7 million in the 2014 period, which was due to lower fuel prices.

Truckload segment revenue decreased $11.3 million, or 9.9%, to $102.8 million in the 2015 period from $114.0 million in the 2014 period. Truckload segment revenue, net of fuel surcharges, decreased to $88.8 million in the 2015 period from $90.3 million in the 2014 period. The increase in profitability in the 2015 period was primarily due to an improvement in our net fuel expense with the lower fuel prices, partially offset by a decrease in our average revenue per tractor.

Dedicated segment revenue increased $10.3 million, or 68.3%, to $25.4 million in the 2015 period from $15.1 million in the 2014 period. Dedicated segment revenue, net of fuel surcharges, increased 90.8% primarily due to an increase in our average fleet size of 76.6% driven by a significant increase in our number of Dedicated contracts with customers. The increase in profitability in the 2015 period was primarily due to an increase in our average revenue per tractor.

Intermodal segment revenue decreased $7.2 million, or 27.3%, to $19.0 million in the 2015 period from $26.2 million in the 2014 period. Intermodal segment revenue, net of fuel surcharges, decreased 21.1% due to the disposal in March 2015 of the dry containers that were used in a portion of our intermodal operations, partially offset by increased volume with our temperature-controlled intermodal trailer service. The increase in profitability in the 2015 period was primarily due to the disposal of our dry container service, which produced a higher operating ratio than our temperature-controlled trailer service, and rate increases beginning in the fourth quarter of 2014.

Brokerage segment revenue increased $3.3 million, or 25.0%, to $16.4 million in the 2015 period from $13.1 million in the 2014 period, primarily due to an increase in volume. The increase in profitability in the 2015 period was primarily due to a decrease in our overhead expenses.  

The following table sets forth for the periods indicated the dollar and percentage increase or decrease of the items in our unaudited consolidated condensed statements of operations, and those items as a percentage of operating revenue:

Salaries, wages and benefits consist of compensation for our employees, including both driver and non-driver employees, employees’ health insurance, 401(k) plan contributions and other fringe benefits. These expenses vary depending upon the size of our Truckload, Dedicated and Intermodal tractor fleets, the ratio of company drivers to independent contractors, our efficiency, our experience with employees’ health insurance claims, changes in health care premiums and other factors. The increase in salaries, wages and benefits from the 2014 period resulted primarily from increases to several components of the amount paid to company drivers, an increase in bonus compensation expense for our non-driver employees and an increase in employees’ health insurance due to an increase in our self-insured medical claims.

Purchased transportation consists of payments to railroads and carriers for transportation services we arrange in connection with Brokerage and Intermodal operations and to independent contractor providers of revenue equipment. This category will vary depending upon the amount and rates, including fuel surcharges, we pay to third-party railroad and motor carriers, the ratio of company drivers versus independent contractors and the amount of fuel surcharges passed through to independent contractors. Purchased transportation expense decreased $2.7 million in total, or 8.6%, in the 2015 period from the 2014 period. Payments to carriers for transportation services we arranged in our Brokerage segment increased $2.8 million to $13.9 million in the 2015 period from $11.1 million in the 2014 period. Payments to railroads and drayage carriers for transportation services within our Intermodal segment decreased $5.9 million to $12.1 million in the 2015 period from $18.0 million in the 2014 period. This decrease was due to the disposal in March 2015 of the dry containers that were used in a portion of our intermodal operations. The portion of purchased transportation expense related to our independent contractors within our Truckload and Dedicated segments, including fuel surcharges, increased $444,000 in the 2015 period. We expect that purchased transportation expense will increase as we grow our Intermodal and Brokerage segments.

Fuel and fuel taxes decreased by $12.2 million in the 2015 period from the 2014 period. Net fuel expense (fuel and fuel taxes net of fuel surcharge revenue and surcharges passed through to independent contractors, outside drayage carriers and railroads) decreased $1.7 million, or 13.8%, to $10.9 million in the 2015 period from $12.7 million in the 2014 period. Fuel surcharges passed through to independent contractors, outside drayage carriers and railroads were $2.3 million in the 2015 period and $4.9 million in the 2014 period. We have worked diligently to control fuel usage and costs by improving our volume purchasing arrangements and optimizing our drivers’ fuel purchases with national fuel centers, focusing on shorter lengths of haul, installing and tightly managing the use of auxiliary power units in our tractors to minimize engine idling and improving fuel usage in the temperature-control units on our trailers. Auxiliary power units, which we have installed in our company-owned tractors, provide climate control and electrical power for our drivers without idling the tractor engine. The decrease in net fuel expense was primarily due to a decrease in the DOE national average cost of fuel to $2.85 per gallon in the 2015 period from $3.94 per gallon in the 2014 period and continued progress with the cost control measures stated above. Net fuel expense represented 8.6% of Truckload, Dedicated and Intermodal segment revenue, net of fuel surcharges, in the 2015 period, compared with 10.3% in the 2014 period.

Depreciation relates to owned tractors, trailers, auxiliary power units, communication units, terminal facilities and other assets. The increase in depreciation was primarily due to a continued increase in the cost of revenue equipment. We expect our annual cost of tractor and trailer ownership will increase in future periods as a result of higher prices of new equipment, which will result in greater depreciation over the useful life.

Gain on disposition of revenue equipment increased to $1.8 million in the 2015 period from $1.3 million in the 2014 period primarily due to an increase in the market value for used revenue equipment. Future gains or losses on dispositions of revenue equipment will be impacted by the market for used revenue equipment, which is beyond our control.

As a result of the foregoing factors, our operating expenses as a percentage of operating revenue, or “operating ratio,” improved to 91.3% in the 2015 period from 92.3% in the 2014 period. The operating ratio for our Truckload segment was 90.5% in the 2015 period and 90.9% in the 2014 period, for our Dedicated segment was 89.9% in the 2015 period and 90.5% in the 2014 period, for our Intermodal segment was 94.9% in the 2015 period and 98.2% in the 2014 period, and for our Brokerage segment was 95.0% in the 2015 period and 95.4% in the 2014 period. Operating expenses as a percentage of operating revenue, with both amounts net of fuel surcharges, improved to 90.2% in the 2015 period from 90.5% in the 2014 period.

The decrease in other non-operating income was primarily due to decreased earnings in the 2015 period by MWL, a 45% owned affiliate.

Our effective income tax rate decreased to 41.0% in the 2015 period from 41.5% in the 2014 period.

As a result of the factors described above, net income increased to $8.4 million in the 2015 period from $7.9 million in the 2014 period. Net earnings per diluted share increased to $0.25 in the 2015 period from $0.24 in the 2014 period.  

Our operating revenue decreased $3.0 million, or 0.9%, to $324.9 million in the 2015 period from $327.8 million in the 2014 period. Our operating revenue, net of fuel surcharges, increased $21.4 million, or 8.1%, to $284.6 million in the 2015 period from $263.2 million in the 2014 period. This increase was primarily due to a $19.9 million increase in Dedicated revenue, net of fuel surcharges, and an $8.7 million increase in Brokerage revenue, partially offset by a $5.6 million decrease in Intermodal revenue, net of fuel surcharges. Fuel surcharge revenue decreased to $40.2 million in the 2015 period from $64.6 million in the 2014 period, which was due to lower fuel prices.

Truckload segment revenue decreased $20.4 million, or 9.1%, to $204.2 million in the 2015 period from $224.5 million in the 2014 period. Truckload segment revenue, net of fuel surcharges, decreased to $175.6 million in the 2015 period from $177.1 million in the 2014 period. The increase in profitability in the 2015 period was primarily due to an increase in our average revenue per tractor, an improvement in our net fuel expense with the lower fuel prices, and the impact of severe weather conditions in the first quarter of 2014 on both freight volumes and operating costs, partially offset by an increase in insurance and claims.

Dedicated segment revenue increased $19.2 million, or 67.1%, to $47.9 million in the 2015 period from $28.6 million in the 2014 period. Dedicated segment revenue, net of fuel surcharges, increased 88.1% primarily due to an increase in our average fleet size of 80.5% driven by a significant increase in our number of Dedicated contracts with customers. The operating ratio for our Dedicated segment in the 2015 period was consistent with the 2014 period.

Intermodal segment revenue decreased $10.5 million, or 21.0%, to $39.4 million in the 2015 period from $49.9 million in the 2014 period. Intermodal segment revenue, net of fuel surcharges, decreased 14.6% due to the disposal in March 2015 of the dry containers that were used in a portion of our intermodal operations, partially offset by increased volume with our temperature-controlled intermodal trailer service. The increase in profitability in the 2015 period was primarily due to the disposal of our dry container service, which produced a higher operating ratio than our temperature-controlled trailer service, rate increases beginning in the fourth quarter of 2014, and the impact of severe weather conditions in the first quarter of 2014 on both freight volumes and operating costs.

Brokerage segment revenue increased $8.7 million, or 35.0%, to $33.4 million in the 2015 period from $24.8 million in the 2014 period, primarily due to an increase in volume. The increase in the operating ratio for our Brokerage segment in the 2015 period was primarily due to an increase in the payments to carriers for transportation services which we arranged as a percentage of our Brokerage revenue.  

The following table sets forth for the periods indicated the dollar and percentage increase or decrease of the items in our unaudited consolidated condensed statements of operations, and those items as a percentage of operating revenue:

The increase in salaries, wages and benefits from the 2014 period resulted primarily from increases to several components of the amount paid to company drivers and an increase in bonus compensation expense for our non-driver employees.

Purchased transportation expense decreased $1.3 million in total, or 2.2%, in the 2015 period from the 2014 period. Payments to carriers for transportation services we arranged in our Brokerage segment increased $7.6 million to $28.6 million in the 2015 period from $21.0 million in the 2014 period. Payments to railroads and drayage carriers for transportation services within our Intermodal segment decreased $9.6 million to $25.1 million in the 2015 period from $34.8 million in the 2014 period. This decrease was due to the disposal in March 2015 of the dry containers that were used in a portion of our intermodal operations. The portion of purchased transportation expense related to our independent contractors within our Truckload and Dedicated segments, including fuel surcharges, increased $729,000 in the 2015 period.

Fuel and fuel taxes decreased by $25.6 million in the 2015 period from the 2014 period. Net fuel expense (fuel and fuel taxes net of fuel surcharge revenue and surcharges passed through to independent contractors, outside drayage carriers and railroads) decreased $5.8 million, or 23.0%, to $19.4 million in the 2015 period from $25.2 million in the 2014 period. Fuel surcharges passed through to independent contractors, outside drayage carriers and railroads were $4.9 million in the 2015 period and $9.5 million in the 2014 period. We have worked diligently to control fuel usage and costs by improving our volume purchasing arrangements and optimizing our drivers’ fuel purchases with national fuel centers, focusing on shorter lengths of haul, installing and tightly managing the use of auxiliary power units in our tractors to minimize engine idling and improving fuel usage in the temperature-control units on our trailers. Auxiliary power units, which we have installed in our company-owned tractors, provide climate control and electrical power for our drivers without idling the tractor engine. The decrease in net fuel expense was primarily due to a decrease in the DOE national average cost of fuel to $2.88 per gallon in the 2015 period from $3.95 per gallon in the 2014 period and continued progress with the cost control measures stated above. Net fuel expense represented 7.7% of Truckload, Dedicated and Intermodal segment revenue, net of fuel surcharges, in the 2015 period, compared with 10.6% in the 2014 period.

The increase in depreciation was primarily due to a continued increase in the cost of revenue equipment.

Insurance and claims consist of the costs of insurance premiums and accruals we make for claims within our self-insured retention amounts, primarily for personal injury, property damage, physical damage to our equipment, cargo claims and workers’ compensation claims. These expenses will vary primarily based upon the frequency and severity of our accident experience, our self-insured retention levels and the market for insurance. The $2.1 million increase in insurance and claims in the 2015 period was primarily due to an increase in the cost of our self-insured auto liability claims. Our significant self-insured retention exposes us to the possibility of significant fluctuations in claims expense between periods which could materially impact our financial results depending on the frequency, severity and timing of claims.

Gain on disposition of revenue equipment increased to $2.9 million in the 2015 period from $1.9 million in the 2014 period primarily due to an increase in the market value for used revenue equipment.

Gain on disposition of facility was $3.7 million in the 2015 period. The disposition of the facility, located in Ontario, CA, is part of our ongoing program to expand and update the footprint of our facilities throughout the United States, in which we have spent over $76 million since 2008. Any future gains or losses on disposition of facilities will be impacted by the market for real estate, which is beyond our control.

As a result of the foregoing factors, our operating expenses as a percentage of operating revenue, or “operating ratio,” improved to 90.3% in the 2015 period from 93.4% in the 2014 period. The operating ratio for our Truckload segment was 90.5% in the 2015 period and 92.6% in the 2014 period, for our Dedicated segment was 90.5% in the 2015 period and 90.4% in the 2014 period, for our Intermodal segment was 94.4% in the 2015 period and 98.1% in the 2014 period, and for our Brokerage segment was 95.3% in the 2015 period and 94.9% in the 2014 period. Operating expenses as a percentage of operating revenue, with both amounts net of fuel surcharges, improved to 88.9% in the 2015 period from 91.8% in the 2014 period. Our operating ratio for the 2015 period, net of the facility disposition gain, improved to 91.5% and, net of both fuel surcharges and the facility disposition gain, improved to 90.2%.

The decrease in other non-operating income was primarily due to decreased earnings in the 2015 period by MWL, a 45% owned affiliate.

Our effective income tax rate increased to 41.0% in the 2015 period from 40.7% in the 2014 period.

As a result of the factors described above, net income increased by 40.4% to $18.5 million in the 2015 period from $13.2 million in the 2014 period. Net earnings per diluted share increased to $0.55 in the 2015 period from $0.39 in the 2014 period.

Liquidity and Capital Resources

Our business requires substantial, ongoing capital investments, particularly for new tractors and trailers. Our primary sources of liquidity are funds provided by operations and our revolving credit facility. A portion of our tractor fleet is provided by independent contractors who own and operate their own equipment. We have no capital expenditure requirements relating to those drivers who own their tractors or obtain financing through third parties.

The table below reflects our net cash flows provided by operating activities, net cash flows used for investing activities and net cash flows (used for) provided by financing activities for the periods indicated.

In the first six months of 2015, net cash flows provided by operating activities of $71.8 million were primarily used to purchase new revenue equipment, net of proceeds from dispositions, in the amount of $39.7 million, to repay $24.4 million of long-term debt, to partially construct regional operating facilities in the amount of $4.4 million, and to pay cash dividends of $1.7 million. In the first six months of 2014, net cash flows provided by operating activities of $40.7 million, borrowings under our credit facility of $16.8 million, and cash and cash equivalents of $12.7 million were primarily used to purchase new revenue equipment, net of proceeds from dispositions, in the amount of $44.7 million, to acquire and partially construct regional operating facilities in the amount of $22.0 million, and to pay cash dividends of $1.7 million.

We estimate that capital expenditures, net of proceeds from dispositions, will be approximately $92 million for the remainder of 2015. Quarterly cash dividends of $0.025 per share of common stock totaling $1.7 million were declared in each of the first two quarters of 2015 and 2014, respectively. We currently expect to continue to pay quarterly cash dividends in the future. The payment of cash dividends in the future, and the amount of any such dividends, will depend upon our financial condition, results of operations, cash requirements, and certain corporate law requirements, as well as other factors deemed relevant by our Board of Directors. As current federal and state bonus depreciation provisions have expired, we expect an increase in our current income tax payments as a portion of our deferred tax liability for property and equipment reverses. We believe our sources of liquidity are adequate to meet our current and anticipated needs for at least the next twelve months. Based upon anticipated cash flows, existing cash and cash equivalents balances, current borrowing availability and other sources of financing we expect to be available to us, we do not anticipate any significant liquidity constraints in the foreseeable future.

We maintain a credit agreement that provides for an unsecured committed credit facility which matures in December 2019. The aggregate principal amount of the credit facility of $50.0 million may be increased at our option, subject to completion of signed amendments with the lender, up to a maximum aggregate principal amount of $75.0 million. At June 30, 2015, there was no outstanding principal balance on the credit facility. As of that date, we had outstanding standby letters of credit of $10.4 million and remaining borrowing availability of $39.6 million. This facility bears interest at a variable rate based on the London Interbank Offered Rate or the lender’s Prime Rate, in each case plus/minus applicable margins.

Our credit facility prohibits us from paying, in any fiscal year, dividends in excess of 25% of our net income from the prior fiscal year. This facility also contains restrictive covenants which, among other matters, require us to maintain compliance with cash flow leverage and fixed charge coverage ratios. We were in compliance with all of these covenants at June 30, 2015.

The following is a summary of our contractual obligations as of June 30, 2015.

Due to uncertainty with respect to the timing of future cash flows, the obligation under our nonqualified deferred compensation plan at June 30, 2015 of 70,671 shares of Company common stock with a value of $1.5 million has been excluded from the above table.

Related Parties

We purchase fuel and obtain tires and related services from Bauer Built, Inc., or BBI. Jerry M. Bauer, one of our directors, is the chairman of the board and chief executive officer and the principal stockholder of BBI. We paid BBI $203,000 in the first six months of 2015 and $289,000 in the first six months of 2014 for fuel and tire services. In addition, we paid $628,000 in the first six months of 2015 and $706,000 in the first six months of 2014 to tire manufacturers for tires that were provided by BBI. BBI received commissions from the tire manufacturers related to these purchases. Other than any benefit received from his ownership interest, Mr. Bauer receives no compensation or other benefits from our business with BBI.

We own a 45% equity interest in MWL, a third-party provider of logistics services to the transportation industry. We received $3.7 million and $3.6 million of our revenue for loads transported by our tractors and arranged by MWL in the six-month periods ended June 30, 2015 and June 30, 2014, respectively. As of June 30, 2015, we also had a trade receivable in the amount of $558,000 from MWL and an accrued liability of $2.6 million to MWL for the excess of payments by MWL’s customers into our lockbox account over the amounts drawn on the account by MWL.

We believe that the transactions with related parties noted above are on reasonable terms which, based upon market rates, are comparable to terms available from unaffiliated third parties.

Off-balance Sheet Arrangements

Other than standby letters of credit maintained in connection with our self-insurance programs in the amount of $10.4 million and operating leases summarized above in our summary of contractual obligations, we did not have any other material off-balance sheet arrangements at June 30, 2015.

Inflation and Fuel Costs

Most of our operating expenses are inflation-sensitive, with inflation generally producing increased costs of operations. During the last two years, the most significant effects of inflation have been on revenue equipment prices, accident claims, health insurance and employee compensation. We attempt to limit the effects of inflation through increases in freight rates and cost control efforts.

In addition to inflation, fluctuations in fuel prices can affect our profitability. We require substantial amounts of fuel to operate our tractors and power the temperature-control units on our trailers. Substantially all of our contracts with customers contain fuel surcharge provisions. Although we historically have been able to pass through a significant portion of long-term increases in fuel prices and related taxes to customers in the form of fuel surcharges and higher rates, such increases usually are not fully recovered. These fuel surcharge provisions are not effective in mitigating the fuel price increases related to non-revenue miles or fuel used while the tractor is idling.

Seasonality

Our tractor productivity generally decreases during the winter season because inclement weather impedes operations and some shippers reduce their shipments. At the same time, operating expenses generally increase, with harsh weather creating higher accident frequency, increased claims and more equipment repairs.

Critical Accounting Policies

The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions about future events, and apply judgments that affect the reported amounts of assets, liabilities, revenue and expenses in our consolidated condensed financial statements and related notes. We base our estimates, assumptions and judgments on historical experience, current trends and other factors believed to be relevant at the time our consolidated condensed financial statements are prepared. However, because future events and their effects cannot be determined with certainty, actual results could differ from our estimates and assumptions, and such differences could be material. We believe that the following critical accounting policies affect our more significant estimates, assumptions and judgments used in the preparation of our consolidated condensed financial statements.

Revenue Recognition. We recognize revenue, including fuel surcharges, at the time shipment of freight is completed. We account for revenue of our Intermodal and Brokerage segments and revenue on freight transported by independent contractors within our Truckload and Dedicated segments on a gross basis because we are the primary obligor in the arrangements, we have the ability to establish prices, we have the risk of loss in the event of cargo claims and we bear credit risk with customer payments. Accordingly, all such revenue billed to customers is classified as operating revenue and all corresponding payments to carriers for transportation services we arrange in connection with brokerage and intermodal activities and to independent contractor providers of revenue equipment are classified as purchased transportation expense.

Accounts Receivable. We are dependent upon a limited number of customers, and, as a result, our trade accounts receivable are highly concentrated. Trade accounts receivable are recorded at the invoiced amounts, net of an allowance for doubtful accounts. Our allowance for doubtful accounts was $439,000 as of June 30, 2015 and $475,000 as of December 31, 2014. A considerable amount of judgment is required in assessing the realization of these receivables including the current creditworthiness of each customer and related aging of the past-due balances, including any billing disputes. In order to assess the collectibility of these receivables, we perform ongoing credit evaluations of our customers’ financial condition. Through these evaluations, we may become aware of a situation where a customer may not be able to meet its financial obligations due to deterioration of its financial viability, credit ratings or bankruptcy. The allowance for doubtful accounts is based on the best information available to us and is reevaluated and adjusted as additional information is received. We evaluate the allowance based on historical write-off experience, the size of the individual customer balances, past-due amounts and the overall national economy. We review the adequacy of our allowance for doubtful accounts monthly.

Property and Equipment. The transportation industry requires significant capital investments. Our net property and equipment was $509.8 million as of June 30, 2015 and $465.7 million as of December 31, 2014. Our depreciation expense was $36.1 million for the first six months of 2015 and $33.2 million for the first six months of 2014. We compute depreciation of our property and equipment for financial reporting purposes based on the cost of each asset, reduced by its estimated salvage value, using the straight-line method over its estimated useful life. We determine and periodically evaluate our estimate of the projected salvage values and useful lives primarily by considering the market for used equipment, prior useful lives and changes in technology. We have not changed our policy regarding salvage values as a percentage of initial cost or useful lives of tractors and trailers within the last ten years. We believe that our policies and past estimates have been reasonable. Actual results could differ from these estimates. A 5% decrease in estimated salvage values would have decreased our net property and equipment as of June 30, 2015 by approximately $10.6 million, or 2.1%.

Impairment of Assets. Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future net undiscounted cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or fair value less the costs to sell.

Insurance and Claims. We self-insure, in part, for losses relating to workers’ compensation, auto liability, general liability, cargo and property damage claims, along with employees’ health insurance with varying risk retention levels. We maintain insurance coverage for per-incident and total losses in excess of these risk retention levels in amounts we consider adequate based upon historical experience and our ongoing review. However, we could suffer a series of losses within our self-insured retention limits or losses over our policy limits, which could negatively affect our financial condition and operating results. We are responsible for the first $1.0 million on each auto liability claim and for the first $750,000 on each workers’ compensation claim. We have $10.4 million in standby letters of credit to guarantee settlement of claims under agreements with our insurance carriers and regulatory authorities. The insurance and claims accruals in our consolidated condensed balance sheets were $13.6 million as of June 30, 2015 and $14.0 million as of December 31, 2014. We reserve currently for the estimated cost of the uninsured portion of pending claims. We periodically evaluate and adjust these reserves based on our evaluation of the nature and severity of outstanding individual claims and our estimate of future claims development based on historical claims development factors. We believe that our claims development factors have historically been reasonable, as indicated by the adequacy of our insurance and claims accruals compared to settled claims. Actual results could differ from these current estimates. In addition, to the extent that claims are litigated and not settled, jury awards are difficult to predict. If our claims settlement experience worsened causing our historical claims development factors to increase by 5%, our estimated insurance and claims accruals as of June 30, 2015 would have needed to increase by approximately $3.6 million.

Share-based Payment Arrangement Compensation. We have granted stock options to certain employees and non-employee directors. We recognize compensation expense for all stock options net of an estimated forfeiture rate and only record compensation expense for those shares expected to vest on a straight-line basis over the requisite service period (normally the vesting period). Determining the appropriate fair value model and calculating the fair value of stock options require the input of highly subjective assumptions, including the expected life of the stock options and stock price volatility. We use the Black-Scholes model to value our stock option awards. We believe that future volatility will not materially differ from our historical volatility. Thus, we use the historical volatility of our common stock over the expected life of the award. The assumptions used in calculating the fair value of stock options represent our best estimates, but these estimates involve inherent uncertainties and the application of judgment. As a result, if factors change and we use different assumptions, stock option compensation expense could be materially different in the future.

We have also granted performance unit awards to certain employees which are subject to vesting requirements over a five-year period, primarily based on our earnings growth. The fair value of each performance unit is based on the closing market price on the date of grant. We recognize compensation expense for these awards based on the estimated number of units probable of achieving the vesting requirements of the awards, net of an estimated forfeiture rate.

Recent Accounting Pronouncements

In May 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-09, “Revenue from Contracts with Customers” which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The standard, which is currently effective for the first quarter of 2018 , will replace most existing revenue recognition guidance required by U.S. generally accepted accounting principles. The adoption of this standard is not expected to have a significant impact on our consolidated condensed balance sheets, statements of operations or statements of cash flows.