THE GEOGRAPHY OF TRANSPORT SYSTEMS
| Function | Main Mode | Nexus |
| Trade City | Water transport (maritime and fluvial). | Waterfront (Heavy industries, Intermodal terminals). |
| Industrial City | Railway | Central stations. Rail terminals and railyards. |
| Mobile City | Highway. Transit. | Shopping districts. Distribution clusters. |
| Network City | Telecommunication | Financial / management districts. High technology clusters. |
A city performs different but interdependent functions related to its connectivity: