Scale Environmental Historical Technological Political Economic
Local Hydrography and geomorphology Culture and settlement patterns Roads Zoning Employment
Regional Altitude Colonies Railways and canals Taxation and regulations Modal competition and complementarity
Continental Distance Colonialism / imperialism Sea routes Trade agreements Markets
Global Oceanic masses Globalization Air transport and telecommunications Multilateral agreements (WTO) Interdependency and comparative advantages
Source: Adapted from B. Hoyle and J. Smith (1998) "Transport and Development: Conceptual Frameworks".
Factors behind the Development of Transport Systems