The advance of transportation technology depends on science and economics. During the 1930s, airships and airplanes competed head-to-head for the Atlantic passenger market. When World War 2 broke out, everything changed. Over the next five years, the combined combatants built over half of a million military airplanes. By the end of the war, four-engine, high-altitude bombers and jet engines were developed. Further investment in airplane technology was stimulated by the Cold War. All this public investment was adapted to civilian passenger jet airplanes. By 1980, dedicated jet airplanes were in use as cargo carriers. Despite the growth of the cargojet market over the past three decades, rising fuel costs and environmental concerns are changing the economics of airships and airplanes again. Investment in large cargo airships is returning. Much of the technology developed for fixed-wing aircraft can be applied to cargo airships. New materials, better engines, control systems and engineering eliminate the need for large ground crews and improve airship reliability and safety. However, two fundamental design issues have yet to be resolved: structural integrity and buoyancy control. A worldwide competition is underway on three continents to develop the dominant design for a cargo airship. This paper examines the alternative design approaches and presents the status of the international competition.

Transportation networks are high-value targets for terrorists and criminals. They are widely accessible, visible, attract intense media attention, and have a significant degree of government ownership. Since the 9/11 terrorist attack in 2001, transportation networks have been the focus of increasing security improvements worldwide. Much of the analytical work with respect to improved security of transportation networks has been related to the costs of the security improvements.

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Until the outbreak of the Second World War, uncertainty existed whether airships and airplanes would dominate intercontinental passenger transportation. The massive investments in fixed-wing aircraft during these hostilities made airplanes the decisive winner, and relegated airships to a negligible role in transportation. As the 21st Century progresses, airships are making a comeback fueled by the 21st Century progresses, airships are making a comeback fueled by the growing demand for air cargo, the unique environmental and operational characteristics of buoyant flight, and advances in engineering science and materials. This paper examines the market niche for airships that exists between air and marine transport and the inherent advantages and disadvantages of this mode of transportation. The economics of airships are considered in light of their past achievements and current designs. The paper concludes with the discussion of two potential applications. A long haul mission for airships between Hawaii and the U.S. mainland is considered for perishable freight, and a short haul mission for airships in northern Canada is considered for the transport of freight and passengers to remote communities.

Gravity models have a long history in the empirical analysis of trade flows and market penetration, but lack a strong economic foundation. This paper demonstrates that the gravity model can be reconciled with existing economic theory within the framework of an interregional trade model. An empirical gravity model of interregional trade is specified for Canadian pork exports to the United States. The estimated results show that, among other things, demand for transport is highly elastic, suggesting that pork producers and truckers have a mutual interest in exploring means to lower freight costs. Finally, the gravity model is used to identify potential markets for each of the five major exporting provinces. The Canadian pork industry has its best opportunity for further penetration in Illinois, Texas, New York and New Jersey.Les modèles de gravitation sont utilisés depuis longtemps pour l'analyse empirique des flux commerciaux et de la pénétration des marchés, mais ils n'ont pas une base économique solide. L'objet de l'article est de démontrer que le modèle de gravitation est compatible avec la théorie économique existante dans le cadre d'un modèle commercial interrégional. Un modèle de gravitation empirique des échanges interrégionaux est utilisé pour décrire les exportations de porc canadien vers les États-Unis. Les résultats calculés font voir, qu'entre autres facteurs, la demande de moyens de transport est très élastique et que, par conséquent, les producteurs de porcs et les camionneurs ont tous deux intérêt à rechercher les moyens d'abaisser les coûts du transport. Enfin, le modèle de gravitation est utilisé pour identifier les marchés éventuels ouverts à chacune des cinq grandes provinces exportatrices. Les meilleures ouvertures à l'exportation du secteur porcin canadien seraient l'Illinois, le Texas, l'État de New York et le New Jersey.