(13) Segment Information Landstar markets its integrated transportation management solutions primarily through independent commission sales agents and exclusively utilizes third party capacity providers to transport customers freight. Landstars independent commission sales agents enter into contractual arrangements with the Company and are responsible for locating freight, making that freight available to Landstars capacity providers and coordinating the transportation of the freight with customers and capacity providers. The Companys third party capacity providers consist of independent contractors who provide truck capacity to the Company under exclusive lease arrangements (the BCO Independent Contractors), unrelated trucking companies who provide truck capacity to the Company under non-exclusive contractual arrangements (the Truck Brokerage Carriers), air cargo carriers, ocean cargo carriers and railroads. Through this network of agents and capacity providers linked together by Landstars information technology systems, Landstar operates an integrated transportation management solutions business primarily throughout North America with revenue of $4.6 billion during the most recently completed fiscal year. The Company reports the results of two operating segments: the transportation logistics segment and the insurance segment. The transportation logistics segment provides a wide range of integrated transportation management solutions. Transportation services offered by the Company include truckload and less-than-truckload transportation, rail intermodal, air cargo, ocean cargo, expedited ground and air delivery of time-critical freight, heavy-haul/specialized, U.S.-Canada and U.S.-Mexico cross-border, intra-Mexico, intra-Canada, project cargo and customs brokerage. Examples of the industries serviced by the transportation logistics segment include automotive products, building products, metals, chemicals, foodstuffs, heavy machinery, retail, electronics and military equipment. In addition, the transportation logistics segment provides transportation services to other transportation companies, including third party logistics and less-than-truckload service providers. Each of the independent commission sales agents has the opportunity to market all of the services provided by the transportation logistics segment. Billings for freight transportation services are typically charged to customers on a per shipment basis for the physical transportation of freight. The results of operations from Landstar Metro and Landstar Servicios are presented as part of the Companys transportation logistics segment. The insurance segment is comprised of Signature Insurance Company (Signature), a wholly owned offshore insurance subsidiary, and Risk Management Claim Services, Inc. The insurance segment provides risk and claims management services to certain of Landstars operating subsidiaries. In addition, it reinsures certain risks of the Companys BCO Independent Contractors and provides certain property and casualty insurance directly to certain of Landstars operating subsidiaries. Revenue at the insurance segment represents reinsurance premiums from third party insurance companies that provide insurance programs to BCO Independent Contractors where all or a portion of the risk is ultimately borne by Signature. Internal revenue for premiums billed by the insurance segment to the transportation logistics segment is calculated each fiscal period based primarily on an actuarial calculation of historical loss experience and is believed to approximate the cost that would have been incurred by the transportation logistics segment had similar insurance been obtained from an unrelated third party. The accounting policies of the segments are the same as those described in the summary of significant accounting policies. The Company evaluates a segments performance based on operating income. No single customer accounted for more than 10% of the Companys consolidated revenue in fiscal years 2018, 2017 and 2016. Substantially all of the Companys revenue is generated in North America, primarily through customers located in the United States. The following tables summarize information about the Companys reportable business segments as of and for the fiscal years ending December 29, 2018, December 30, 2017 and December 31, 2016 (in thousands): Transportation Logistics Insurance Total 2018 External revenue $ 4,562,796 $ 52,348 $ 4,615,144 Internal revenue 37,872 37,872 Investment income 3,816 3,816 Interest and debt expense 3,354 3,354 Depreciation and amortization 43,570 43,570 Operating income 303,426 28,309 331,735 Expenditures on long-lived assets 9,747 9,747 Goodwill 38,232 38,232 Capital lease additions 46,595 46,595 Total assets 1,175,040 205,524 1,380,564 2017 External revenue $ 3,599,382 $ 46,982 $ 3,646,364 Internal revenue 37,110 37,110 Investment income 2,498 2,498 Interest and debt expense 3,166 3,166 Depreciation and amortization 40,560 40,560 Operating income 209,615 34,353 243,968 Expenditures on long-lived assets 15,586 15,586 Goodwill 39,065 39,065 Capital lease additions 33,560 33,560 Total assets 1,132,766 219,694 1,352,460 2016 External revenue $ 3,121,210 $ 46,424 $ 3,167,634 Internal revenue 36,118 36,118 Investment income 1,502 1,502 Interest and debt expense 3,794 3,794 Depreciation and amortization 35,796 35,796 Operating income 187,813 35,438 223,251 Expenditures on long-lived assets 22,645 22,645 Goodwill 31,134 31,134 Capital lease additions 61,504 61,504 Total assets 913,667 182,924 1,096,591