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Conceptual System Model of Transport and Traffic

Website: Hamburg Open Online University
Kurs: MoGoLo - Mobility of Goods and Logistics Systems
Buch: Conceptual System Model of Transport and Traffic
Gedruckt von: Gast
Datum: Samstag, 19. Oktober 2024, 00:23

Beschreibung

In this section, you will learn more about the different elements and relations of the conceptual system model of transport and traffic.

1. Introduction

This section gives you an overview of the conceptual system model of transport and traffic and helps you to understand the upcoming sections better, as their structure is based on the elements and relations presented in this section.

After learning more about the activities, that are driving the system, the persons, goods and information of the system are being presented to you. Subsequently, you learn more about the movables as well as the needed infrastructure. This topic is concluded by the facilities of the system. Besides the presentation of the elements, you will learn more about the relations between the different elements like transport, traffic, land use and accession

This framework for transportation systems analysis and design, which was developed by Ridley and Sjöstedt (1996) helps to illustrate the possibilities of different transport chains and the inherent characteristics of their elements as well as the interactions between these elements. The framework  is based on a conceptual model for transportation presented by Manheim (1979).

The following figure "Conceptual system model of transport and traffic" shows the conceptual system model of transport and traffic by Flämig (2002). It consists of 5 elements (green circles) and 4 relations (lines between the circles).

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The main elements of the conceptual system model are:
  • Moving objects like goods, people, bytes
  • Carrying objects (movables) like vessels/vehicles
  • Traffic Infrastructure
  • Facilities and
  • Activities, that drive the system

All elements are connected via relations. The relations between the main elements are:
  • Transport
  • Traffic 
  • Land Use
  • Accession 

All elements and relations are explained to you in detail on the following pages of this topic.

If you want to listen to Prof. Dr.-Ing. Heike Flämig explaining the conceptual system model, you can check out the following video. 


Now you know of which elements and relations the conceptual system model consists.

Literature
Flämig, H.; Sjöstedt, L.; Hertel, C. (2002): Multimodal Transport: An Integrated Element for Last-Mile-Solutions? Proceedings, part 1; International Congress on Freight Transport Automation and Multimodality: Organisational and Technological Innovations

Manheim, M.L. (1979): The Challenge of Transportation Systems Analysis. In: Fundamentals of Transportation Systems Analysis, MIT Press., pp.10-49

Sjöstedt, L. (1996): A Theoretical Framework – from an Applied Engineering Perspective. In: Eurocase - Mobility, Transport and Traffic: in the perspective of growth, competitiveness, employment. Paris, France.

1.1. Quiz - Elements of the conceptual system model

In order to test, if you understood it, you can test yourself by answering the following question:

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2. Activities

On this page, the first element „Activities“ of the conceptual system model will be presented to you.

Activities are driving the system and require the presence of persons and goods at specific facilities that are specially designed to incorporate certain types of activities. 


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Each such activity creates the demand to ensure accession to the facility where the activity is scheduled to take place. This creates the demand for offering transport options. When the transport option is realised, traffic is generated.
Thus all demand is a derived demand, which are all generated by the planning and execution of human activities.

To better illustrate this, here are a few examples for goods movement relevant activities:
  • design of products
  • procurement strategies
  • production concepts
  • distribution concepts
  • waste management
  • re-distribution concepts
  • location choice

Literature
Flämig, H.; Sjöstedt, L.; Hertel, C. (2002): Multimodal Transport: An Integrated Element for Last-Mile-Solutions? In: Conference Proceeding of the International Conference “Freight Transport Automation and Multimodality. Organisational and Technological Innovations,Delft, Niederlande


3. Persons, goods and information

This page will give you more information about the second element „Persons, Goods and Information“ of the conceptual system model. All are types of flows that occur in logistics. 

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Goods, persons and bytes are the objects of flow.
  • Persons as the object of flow are named passengers.
  • Goods are often bundled and packed to a packaging unit so the number of moving goods is bigger than the number of shipments.
  • Bytes are the object of information flow.
  • Information and communications technology (ICT) can change the form and number of objects that flow (e.g. Internet of Things).

The two important differences between passengers and goods are:
  • Goods need to be handled (loaded and unloaded), while most passengers are capable of using their legs (built in movement tools) while embarking and disembarking a vehicle or vessel.
  • Passengers are intelligent and require much less planning support than (today) the goods which are entirely dependent on someone carrying out the forwarding function for each movement stage.
 
Without transport, the flow of goods, persons or information is not possible.  


Transport 

Transport is the change of address from A to B of persons and goods. Excluding here pedestrians, who only use their legs (manual tools) transport is an interaction between persons/goods and vehicles/vessels.
A change of position is a change of system state. There are only three system states relating to transport: 
  • it has not yet left A, 
  • it has left A but not reached B and 
  • it has reached B.
In contrast traffic has an unlimited number of possible states.

Transport is measured either by volume (tonnes) or by transport work (TKT). The transport capacity is the maximum load of a specific vehicle/vessel in tonnes or m³ or the maximum amount of goods in tonnes or m³ that can be moved from A to B per time unit, usually day or week.

Thus transport statistics is usually given in tonnes or TKT, which says nothing about the value added by the transport. This is a growing problem as supply chains grow longer and the average specific goods value increases. In e.g. air transport it makes little sense to talk about how many tonnes of micro chips have been transported.
 
Now you know the element “goods, persons and bytes” and what transport has to do with it. 

Literature
Flämig, H.; Sjöstedt, L.; Hertel, C. (2002): Multimodal Transport: An Integrated Element for Last-Mile-Solutions? In: Conference Proceeding of the International Conference “Freight Transport Automation and Multimodality. Organisational and Technological Innovations,Delft, Niederlande

3.1. Quiz - Goods and persons

In order to test your new knowledge, you can answer the following question.


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4. Movables

In order to further understand the conceptual system model, we will now deal with the third element „Movables“. In the upcoming topics, the different vehicle types for each means of transport will be explained there. 

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A vehicle/vessel is a tool designed to perform the movement on infrastructure for the purpose of carrying a load of persons and/or goods. It needs to have as a basic function a system to support and safely contain its load.
In addition it has as a minimum needs the following functions:
  • A system that supports it relative to its infrastructure. If the supporting medium is the ground the tool is called a vehicle. It is called a vessel if it is mainly supported by air or water. 
  • A system for forward propulsion by muscle or machine power relative to the infrastructure. 
  • A system for steering, i.e. change direction. 
  • A system for braking.

Some examples for movables are:
  • trucks / cars,
  • trains,
  • ships,
  • airplanes,
  • cargo bikes,
  • drones,
  • hand truck, etc.

The relation between vehicles/vessels and infrastructure is called traffic.


Traffic 

Traffic is  the interaction between vehicles/vessels and infrastructure and the movement of vehicles or vessels.
  • These movements take place on infrastructure with movables. In other words: Excluding here pedestrians, who only use their legs (manual tools) traffic is an interaction between vehicles/vessels and infrastructure.
  • Movements in traffic requires space, and since space is restricted, every traffic system has a maximum capacity.
  • Traffic is where most of the resulting metabolism of the system (energy use to drive the system) takes place. Traffic is also the last in the chain of derived demands and therefore the most difficult to change. This must be remembered e.g. when carrying out environmental analysis and suggesting changes of traffic systems.

Traffic flow and capacity are measured in traffic units per hour that are passing a specific segment of infrastructure, such as an airport field or a road crossing (e.g. annual average daily traffic (AADT) in vehicles per day).

Traffic density is measured in the number of traffic units that at a specific point of time is enclosed within a traffic segment.

Traffic occupation is the percentage of available space within a specific segment that is used by vehicles/vessels at a specific point of time, such as the number of quay meters in a harbour used by ships at a certain hour.

Goods traffic Sub-Systems
The traffic can be divided into three different parts. For the goods traffic, the following figure shows the three kinds of goods traffic (land, air and water traffic) and the subcategories. 


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Literature
Bloech, J. (1997): Vahlens großes Logistiklexikon. München: Beck [a. o.]

Flämig, H.; Sjöstedt, L.; Hertel, C. (2002): Multimodal Transport: An Integrated Element for Last-Mile-Solutions? In: Conference Proceeding of the International Conference “Freight Transport Automation and Multimodality. Organisational and Technological Innovations,Delft, Niederlande

4.1. Quiz - Characteristics of traffic

Now that you have learned quite a bit about movables and traffic, you can test your knowledge with this question:

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5. Infrastructure

After you got to know more about the three elements before, this chapter will give you more information about the element „Infrastructure“. In the following MoGoLo topic cluster, this will be differentiated depending on the mode of transport.


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Infrastructure is the underlying (invisible) structure of a human society and is often assumed to be limited to publicly accessible space, such as schools, theatres, sports arenas, roads, railways, paths in the wilderness etc.. Besides that, infrastructure often means our systems of roads, railways, airports and harbours. 
In academic language this is a too narrow interpretation that neglects the abstract dimension of the concept. Therefore, in the further topic cluster the following definition is used:
Infrastructure is the structure of all human made systems that are created to enable some kind of man made flow of information, energy, materials and/or living organisms, including the positions of all facilities that are served by these systems.
The transportation infrastructure is limited to enabling flows of persons and goods and in a wider concept data as well. 

Examples for infrastructure: 
  • streets/road
  • railways and stations
  • waterways and harbors
  • air corridors and airports
  • pipe lines
  • data lines
 
Infrastructure network
Various infrastructures form a large infrastructure network, which can be seen in the figure "Network structure". You can see different kind of networks for the road, rail and water infrastructure. The combination of all three networks forms the transportation infrastructure.  


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The connection between infrastructure and facilities is called land use. 


Land use

Land use 
  • is the location of facilities at specific sites. 
  • is the combined result of public planning and complex market mechanisms.
  • may be seen as an interaction between a planned facility and infrastructure in its widest sense. 
  • results in giving the facility a permanent address.

Literature
Flämig, H.; Sjöstedt, L.; Hertel, C. (2002): Multimodal Transport: An Integrated Element for Last-Mile-Solutions? In: Conference Proceeding of the International Conference “Freight Transport Automation and Multimodality. Organisational and Technological Innovations,Delft, Niederlande

6. Facilities

On this page, you will learn something about the last element “Facilities” of the conceptual system model.

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Facilities are the immovables of the systems. A facility is a fixed (temporary) structure, in most cases some type of building or open arena, which is dedicated to some specific types of human activities. Important categories of facilities are homes, schools, offices, shops etc. Two especially important categories of facilities for logistics are production facilities and storage facilities.

Although in the general version of the conceptual system model the transportation system does not include any facilities, a closer analysis of a transportation system often requires the incorporation of specific facilities. This is due to the hierarchical character of transportation systems.

Examples for facilities:
  • company sides (trade, manufacturing, services)
  • facilities for logistics services, transport terminals, micro hubs
  • households
  • public facilities
 
The relation between the two elements facilities and goods, persons and information is called accession. 


Accession

Accession
  • is an interaction between persons/goods and facilities.
  • is the provision of options to move persons and goods between the locations of two facilities A and B at specific times. 
  • can be just the theoretical possibility of moving between locations at any time, or it could be the planned and even reserved possibility to carry out a transport at a specific point of time. In the first case accession is often measured in required transport time and (if relevant) frequency (time distance between options). In the latter case arrival/delivery within a specific time window is the normal criterion (Just-in-Time).

Literature
Flämig, H.; Sjöstedt, L.; Hertel, C. (2002): Multimodal Transport: An Integrated Element for Last-Mile-Solutions? In: Conference Proceeding of the International Conference “Freight Transport Automation and Multimodality. Organisational and Technological Innovations,Delft, Niederlande

6.1. Quiz - Elements of the system model

After learning something about the last element of the system model, feel free to test your knowledge by answering the following questions. 


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7. Lessons learned

  • Knowledge and definition of elements and processes of transport of the system model.
  • Understanding of interaction of transport and traffic, demand and supply on different layers of the transport system.

8. Literature

Bloech, J. (1997): Vahlens großes Logistiklexikon. München: Beck [a. o.]  

Flämig, H.; Sjöstedt, L.; Hertel, C. (2002): Multimodal Transport: An Integrated Element for Last-Mile-Solutions? Proceedings, part 1; International Congress on Freight Transport Automation and Multimodality: Organisational and Technological Innovations. Delft, Suppl.

Manheim, ML. (1979): The Challenge of Transportation Systems Analysis. In: Fundamentals of Transportation Systems Analysis, MIT Press.,  pp.10-49  

Sjöstedt, L. (1996): A Theoretical Framework – from an Applied Engineering
Perspective.
In: Eurocase - Mobility, Transport and Traffic: in the perspective of 
growth, competitiveness, employment. Paris, France.