C Transportation Networks1. Transport Networks2. The Topology and Typology of Networks3. Networks and Space

1. Transport NetworksTransport networkFramework of routes between locations:A permanent track (e.g. roads, rail and canals).A scheduled service (e.g. airline, transit, train).Various types of links between points along which movement can take place. Creates accessibility.Network structureRanges from centripetal to centrifugal.Express inequalities between places.Express transport rates.Integration processes impacted on the structure and flows of transportation networks.

Centrifugal and Centripetal NetworksCentrifugalCentripetal

Network StructuresCentralizedDecentralizedDistributed

Transport HubPoint-to-PointHub-and-SpokeHub

Cost, Revenue and Level of Network Coverage537410Cost: 10Revenue: 15Benefit: 5ACost: 12Revenue: 18Benefit: 6BCost: 14Revenue: 25Benefit: 11CCost: 19Revenue: 29Benefit: 10D

Impacts of Integration Processes on Networks and FlowsNetworkFlowsBefore IntegrationAfter IntegrationInternational border

2. The Topology and Typology of NetworksTopologyThe arrangement and connectivity of a network.Each network has a specific topology.

Topology of a NetworkNodeLinkUnidirectional linkBi-directional linkEntry and exitExitEntry

Types of Network TopologyMeshHub-and-SpokeLinearTree

Network Strategies to Service a Set of LocationsABCDEF

2. The Topology and Typology of NetworksMode of territorial occupationClearly defined and delimited:Strictly reserved space for transport infrastructure.Ownership can also be clearly established.Major examples include road, canal and railway networks. Vaguely defined and delimited:Space may be shared with other modes.Not the object of any particular ownership, only rights of passage.Examples include air and maritime transportation networks. Without definition:Space has no tangible meaning, except for the distance it imposes.Little control and ownership are possible.Agreements must be reached for common usage.Examples are radio, television and cellular networks.

Mode of Territorial Occupation by Transport NetworksClearly definedVaguely definedWithout definitionRoadRailAir corridorMaritime corridorCellular coverageOverlapNo service

3. Networks and SpaceTransportation networks and spaceTerritorial organization of economic activities.Efforts incurred to overcome distance.Measured in absolute or relative termsRelated to continuity, topographic space and spatial control.The territory is a topological space having two or three dimensions, depending on the transport mode considered.Flows and infrastructures are linear; having one dimension.

Transport Networks and SpaceTransport NetworkSpaceAccessibility

Absolute and Relative Distance in a Network10 km30 minutes

3. Networks and SpaceSpatial continuityUbiquity:The possibility to reach any location from any other location. Fractionalization:The possibility for a traveler or an unit of freight to be transported without depending on a group. Instantaneous:The possibility to undertake transportation at the desired moment. Topographic spaceNot a continuous space.Variety of physical features.Level of influence on the structure of transport networks:Depends on the mode.

Networks and Spatial ContinuityABC

3. Networks and SpaceTool for spatial controlRoman and Chinese empires relied on transportation networks to control their respective territories.During the colonial era, maritime networks became a significant tool of trade, exploitation and political control.In the 19th century, transportation networks also became a tool of nation building and political control.In the 20th century, road and highways systems were built to reinforce this purpose.For the early 21st century, telecommunication networks have become means of spatial cohesion and interactions.

D Transportation Supply and Demand1. Context2. Supply and Demand Functions3. Supply / Demand Relationships

1. ContextTransport supplyThe capacity of infrastructures and transport modes.Over a geographically defined transport system and for a specific period of time.Expressed in terms of infrastructures, services and networks.Quantification:Per unit of time and space.Number of passengers.Volume (for liquids or containerized traffic).Mass (for freight).

1. ContextTransport demandExpression of the transport needs of a territory:Generated by the economy.Composed persons, institutions and industries.Generates movements of people and freightThose needs can be satisfied, fully, partially or not at all.Quantification:Number of people, volume, or tons per unit of time and space. Ton-km and Passenger-kmMeasures expressing the realized transport demand.Compares a transported quantity with a distance.

Ton-Miles of Freight Transported within the United States, 1975-2000 (millions)

Passenger-Miles Transported within the United States, 1975-2000 (millions)

Share of Total Domestic Freight Activity by Mode, G7 Countries, 1996

Growth Factors in Transport DemandQuantity of Passengers or FreightAverage DistanceGrowth in production and consumptionIncome growthIndustrial relocationEconomic specializationSuburbanizationPassenger or ton-kmsKMPassengersFreight

2. Supply and Demand FunctionsTransport supplyFunctions representing what are the main variables influencing the capacity of transport systems.Variables are different for each mode.Road, rail and telecommunications:Dependent on the capacity of the routes and the vehicles.Air and maritime transportation:Influenced by the capacity of the terminals.Transport of people and freight:Expressed in number of vehicles, people or tons over a time period.The supply of one mode influences the supply of others.Dependent of the capacity of intermodal infrastructures.

Major Supply Variables for Transportation ModesRoadRailAirMaritimeLanesWidthSpeed limitParkingSpeedPassengersTonnageAtmospheric ConditionsTracksGradeYardsTransshipmentSpeedPassengersTonnageCorridorsSpeedPassengersTonnageRunwaysDockwaysCanalsLocksDocksTransshipmentSpeedTonnageRoutesTerminalsVehicles

2. Supply and Demand FunctionsTransport demandRelated to economic and social activity patterns.Stable and recurrent; allows the planning of services.Unstable and uncertain; difficult to offer an adequate level of service. Passengers:Function of demographic attributes of the population such as income, age, standard of living, race and sex, as well as modal preferences. Freight:Function of economic activities (GDP, commercial surface, number of tons of ore extracted, etc.) and of modal preferences. Information:Population (telephone calls) and the volume of financial activities (stock exchange).Standard of living and education levels.

3. Supply / Demand RelationshipsTransport supply and demand interactionsSupply curve:Quantity of transport services offered according to price.The higher the price, the more suppliers are willing to offer a transport service.Demand curve:Quantity of transport services consumed according to price.The higher the price, the less users are willing to consume that service.Equilibrium price:Supply and demand interact until an equilibrium is reached.Quantity of transportation the market is willing to use at a given price.Quantity being supplied.

Classic Transport Demand / Supply FunctionTrafficCostDemandSupplyT1C1DS1S2C2T2Equilibrium

2. Supply and Demand FunctionsConsiderationsEntry costs:High in some sectors (maritime, rail and air). Oligopolisitc.Low in other (trucking).Public sector:High level of public involvement. Provision of transport infrastructures.Transport costs are partially subsidized.Government control (and direct ownership).Elasticity.Variation of demand in response to a variation of cost.Transport demand has a tendency to be inelastic.Commuting: inelastic in terms of costs but elastic in terms of time.Freight: inelastic.Air transportation: elastic (tourism).

Transport Elasticity by ActivityTrafficCost100%0%EmergencyCommutingMajor PurchaseSpecial EventSocial ActivitiesRecreation

Transport Supply, Demand and Travel TimeT>AT