National Interstate Corporation and its subsidiaries operate as an insurance holding company that underwrites and sells traditional and alternative property and casualty insurance products to the passenger transportation, trucking and moving and storage industries, general commercial insurance to small businesses in Hawaii and Alaska and personal insurance to owners of recreational vehicles throughout the United States. The Company is a specialty property and casualty insurance company with a focus on the transportation industry. The Company operates through property and casualty insurance segment. The Company offers approximately 40 product lines in the specialty property and casualty insurance market, which it groups into approximately four general business components: alternative risk transfer (ART), transportation, specialty personal lines, and Hawaii and Alaska based on the class of business, insureds' risk participation or geographic location.