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In most of the countries transport planning is treated as a part of general economic planning and no special attention has been paid, but now not only developed countries but developing countries have also realised the need for separate planning for the transportation, not only for the existing system but for the future development also.
The study of development and planning is basically a study of interaction between man, land and activity in the form of spatial organisation of economy. After industrial revolution and rapid growth of urbanisation, development in the field of transport is enormous both in infrastructures, speed as well as in transport technology. Nowadays every country of the world is having its own national transport system, not in isolation but as a part of international system of transportation. Transport now has, as ever, become an integral and essential part of the economy and requires a planned growth, which should be ‘sustainable’.
In fact, transport planning is the process of regulating and controlling the provision of transport to facilitate the efficient operation of the economic, social and political life of the country at the lowest social cost. In practice, this means assuring adequate transport capacity and efficient operations to meet the needs generated by the nation’s geographical array of activities.
Planning Process:
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The primary aim of transport planning is the identification and evaluation of the future transport needs. The basis of transport planning process has been depicted in Figure 9.1.
The four main stages of the transportation planning process are:
(i) Transportation survey, data collection and analysis;
(ii) Use of transportation model;
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(iii) Future land use forecasts and alternative policy strategies; and
(iv) Policy evaluation.
Survey and Data Collection:
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The entire planning process of transportation, may be local, regional or national, is based on survey and data collection. This includes all types of literature and data (both government and non-government) available on transportation, journey behaviour patterns, nature and intensity of traffic, freight structure, cost and benefits, i.e., income, employment estimates, etc.
The comprehensive knowledge of traffic flows and patterns within a defined area is essential. In addition to traffic data, planners also require land use and population data for their study area. In this connection West Midlands Transportation Study (1968) provides a format, which is useful for transport survey and data collection (Figure 9.2).
The survey should be well defined and be divided in ‘zones’ so that origins and destinations of trips can be geographically monitored. The data collection regarding existing travel patterns is time consuming as well as a costly affair. It involves both ‘roadside-interview’ and ‘home-interview’. The variables for both types of interviews are given in the Table 9.1
The details-of existing transport network are an important source of information. In some cases, a very detailed description of links and nodes in terms of vehicle speed, carriage-way width and nodal type is collected. Travel times and network characteristics of public transport networks are simultaneously collected. Finally, data processing should be done. When this has been completed, planners can begin their data analysis.
The Transportation Model:
The second stage of the transportation planning process is to use the collected data to build up a transportation model. This model is the key to predicting future travel demands and network needs and is derived in four recognised stages, i.e., trip generation, trip distribution, traffic assignment and model split.
Trip Generation:
The first stage of model building process is that of trip generation. Trips are made for a variety of purposes and for various land uses. For convenience, trips are often split into two groups:
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(i) Home-based trips:
Such trips have one trip end at the home of the person making the trip, which may be either the origin or destination of the given trip.
(ii) Non-home-based trips:
These have neither origin nor destination trip-end at the home of the person making the trip.
This initial part of the transport model expresses trip-making relationships in a mathematical form so that ultimately we can calculate the total number of trips-ends originating from the defined survey zones.
Multiple regression technique are often used to calibrate a trip-generation model incorporating the above household variables. This model takes the following general form:
Y = a +b1 x1 + b2 x2 +….. + bn xn
where Y = number of trips (by mode and purpose) generated in a given zone
a = constant term
b1…bn = regression coefficients relating to independent variables (e.g. household income, car-owner- ship, house-hold structure, etc.)
New estimates of the independent variables are made and inserted into the equation in order to estimate future levels of trips generation. Multiple regression analysis, therefore, provides a suitable method for estimating future trip levels. Its main disadvantage, however, is that the original regression estimates have been established at a given point in time and are expected to remain constant over the period for which the forecast is required.
Consequently, a more recent approach to trip generation has been to use a technique known as ‘category analysis’. The trip-generation stage of the planning process estimates the total number of trips originating in the survey area at one or more future dates.
Trip Distribution:
This is the next stage in the transportation model, it involves on analysis of trips between zones. Lane (1971) states the function of this stage of the model:
It is the function of trip distribution to calculate the number of trips between one zone and another, given the previously determined numbers of trip ends in each zone together with further information on the transport facilities available between these zones.
For example, given that in zone I, gi trip ends are generated and that in zone j, ai trip ends are attracted, it is the purpose of the trip distribution model to determine the number of trips (tij) which would go from zone i to zone j. That is, the trip distribution model calculates the proportion of trip ends generated in zone i which would travel between i and j and so take up a certain proportion of the available attractions in zone j.
Overall, the distribution stage of the transportation model has received considerable attention and has been the main source of research over the last quarter of a century. The earliest attempts to produce a future trip distribution matrix used simple growth factor methods, taking the following general form:
Tij = tjj × E
where Tij = future flow from zone i to zone j
tjj = base year flow from zone i to zone j
E = agreed expansion factor
The value of the expansion factor can take various forms. For example, Bevis (1956) put forward the idea of a crude expansion factor of the following format:
E=1/2 (Ti/ti × Tj/tj )
Where Tij= future origin zone
ti = base year origins zone i ,
Tj = future destinations zone j,
tj = base year destinations zone j.
This simple model was further refined, but growth-factor techniques are now rarely used. The method is a crude one and has been superseded largely because it does not attempt to measure any future resistance to travel between zones. For this reason, synthetic models tend to be widely used to model trip distribution. The trip-distribution stage of the transport model has received much attention and has been the source of many new developments.
Traffic Assignment:
The third stage of the modelling process is that of traffic assignment, its aim being to stimulate route choice through a defined transport network. Traffic assignment may be considered in two parts.
First, it is necessary to define the transport network and determine criteria for route choice through the network.
Second, using the inter-zonal trip matrix as the input data, trips are assigned to this network.
When future trip levels are assigned it is possible to assess deficiencies in the existing transport network and so determine a list of construction priorities. Network description refers to the process where the highway network is broken down into links and nodes. For each link, data is required on its length, road type, vehicle travel time and traffic capacity. When coding the road network, links are usually identified by the node numbers at each of its ends. In addition to such route-intersection nodes, zone-centroid nodes are also defined. In the assignment process, all traffic originating in a particular traffic zone is assumed to be loaded on to the network at this latter type of node.
The early transportation studies used manual assignment techniques, but with the universal use of computer analysis, the transport network can be specified to the computer in a most detailed manner. Special data collection surveys (especially of journey times) are usually needed to provide this network specification information.
For deriving minimum route paths through the network, it is normally assumed that travellers choose the path, which minimises travel time. This applies for both private and public transport journeys. Travel time has been used in most transportation studies although it is usually used as an approximation for minimising the travel costs of a journey.
A more recent and more realistic assignment procedure is that of capacity restraint. This may be used, with or without diversion curves, for assignments to road and public transport networks. After the initial assignment to the given network, new travel times are calculated for each link. New minimum path trees are then calculated and the assignment procedure reiterated. Further reiterations may follow until most or all of the future traffic volume has been assigned to the network.
This type of procedure has tended to supersede other assignment techniques and has been used in most of the second-generation transportation studies. The assignment stage of the transportation model therefore is the process by which trips are assigned or loaded on to the road network. At the end of this stage, construction priorities can be established and alternative proposals put forward.
Model Split:
This term is used by transport planners to describe the phase where the choice of travel mode is incorporated into the model. The positioning of this stage is neither fixed nor singularly definable since elements of model split are part of the other stages. Its position within the transportation model differs between studies. It is either used at the trip generation stage by stratifying the total trips or at the assignment stage of the model. The main purpose of the model-split stage is to determine the trip shares of public, as against private, transport.
Future Land Use and Travel Demand Forecasting:
The forecasting of future land use inputs is a precarious task, for two important reasons. Firstly, transport planners have to rely on the judgment of to the types of planner for most of their land use forecasts. This information is vitally important since it has a profound effect upon travel forecasts. Secondly, long-term forecasting is beset with many statistical problems.
Since transportation planners are usually working at least 10, and sometimes 25 years ahead, their estimates are inevitably open to much criticism. Nevertheless, estimates of future travel demands have to be made using the best methods, which are available. Some of these forecasting problems are amplified below in the listing of the main land use inputs necessary for travel forecasts to be made.
The most important variables are:
(i) Population – its size, age structure and distribution.
(ii) Employment – as the journey to work is the greatest travel demand.
(iii) Personal income and expenditure.
The above groups of variables have a compound influence upon the overall level of demand for travel at some future date. Further complications arise when their impact upon the spatial pattern of this demand is assessed. So, forecasts of population and economic variables are an important input into the use of the transportation model for forecasting future travel demands.
Evaluation:
The final stage of the transportation planning process is one of evaluating the alternative policies, which have been suggested. The evaluation stage is probably the most important of all, yet has received only limited research attention. An economic evaluation of transport proposals is necessary because vehicle-km and road space are commodities, which are not directly bought and sold.
The technique of cost benefit analysis has consequently evolved as an investment criterion in the public sector. As such, it provides an economic evaluation. On the cost side of the calculation, estimates are made for capital outlay, land purchase and maintenance.
The benefits are those accruing to users, e.g., savings in time, vehicle operation and accidents. The individual costs and benefits are assessed over a particular number of years and discounted back to the base year so that a rate of return can be calculated. On the basis of ‘transportation plan’, transport policies should be formulated and implemented properly so that systematic ‘sustainable’ development of transport can be done.
Transport Policy:
Nowadays every country is particular regarding the planned development of transport system, thus formulate their own transport policy, which depends upon their needs and resources. The nature of transport policy varies with time and space. In formulating transport policy, one should take into consideration the ‘coordination’ and ‘competition’.
The coordination involves the relationship between two or more different modes of transport. On the others hand, competition has occurred as a consequence of the public/private sector interaction. The transport policy also differs with the type of government, i.e., socialistic, democratic, etc. Inspite of variations in policy, which are natural, there are certain points which are useful if incorporated in transport policy. The points are from transport policies of the countries like USA, UK, Netherland, and European Union. These are as follows:
Transport Demand Management in USA:
‘Transport Demand Management’ (TDM) system as a part of transport policy has been adopted in USA. TDM is the art of modifying travel behaviour in order to reduce the number of trips or modify their nature. It may be categorised according to whether it mainly affects trip generation, trip distribution, and model choice or route selection. As Table 9.2 shows, some implementation strategies rely on changes to the transport system, others on land use policies and still others on alterations to employment conditions and social values.
In the field of TDM, the USA has done considerable work. Persuading a number of large companies to introduce flexible working hours (‘flexitime’) is a logical way to reduce congestion at peak periods. The introduction of car-pooling is another step in this direction. The most TDM measures are ones that require employers to reduce the number of peak-period car trips made by their worker. In USA at least 20 suburban communities have enacted such programmes.
Netherlands’s Policy for ‘Sustainable Development:
National Environmental Policy Plan or NEPP of Netherland has been adopted in 1989. NEPP is an example of environmental protection as well as policy for the control of pollution created by transport. The NEPP recognises that safeguarding environmental quality on behalf of what it calls ‘sustainable development’ will be a process that will last for several decades. The NEPP is the first step in this process: it contains the medium-term strategy for environmental policy, which is directed at the attainment for sustainable development over the longer period.
The objectives of the NEPP are:
i. Vehicles must be as clean, quiet, safe and economical as possible;
ii. The choice or mode for passenger transport must result in the lowest possible energy consumptions and the least possible pollution; and
iii. The locations where people live, shop, work and spend their leisure time will be coordinated in such a way that the need to travel is minimised.
The approach of the NEPP is shown in Figure 9.3. As pollution from road traffic is seen as a three-step process, these objectives are to be met through a ‘three-track’ response, the tracks being those of technical vehicle standards, reducing ‘automobility’ and instigating urban traffic measures.
As shown in Figure 9.3, the three-track approach has been developed to the abatement of environmental pollution. The first track consists of a series of measures to convert the vehicle fleet into one that is the cleanest possible.
The second track, of reducing car use, aims to shift people from cars to public transport for the longer journeys and to cycling or walking for the shorter ones. This is to be achieved through provision of more and better facilities for cycling and public transport, more subsidies, better fare and ticket integration and publicity campaigns.
However, it is recognised that if the policy is to seek a balance between individual freedom, accessibility and the environment, the only way to achieve this is to control the use of cars. Therefore, the strategy is to increase variable motoring costs through fuel taxation and road pricing. Car commuting will be discouraged through a variety of TDM measures including ‘kilometre reduction plans’, whereby companies and institutions will have to draw up and then implement plans to reduce the distance travelled by employees in the course of work and in commuting to it.
Additionally, the second track will improve the transport of freight by rail and water and will tighten up physical planning policy, to ensure that businesses which are labour-intensive or amenities which attract numerous visitors are not permitted to locate at places which are not well served by public transport.
As well as having cleaner vehicles, which are used less, the NEPP recognises – the third ‘track’ – that further measures are necessary to alleviate the problems at a local scale. These include stricter enforcement of parking controls, traffic management to influence drivers’ choice of routes, circulation schemes to slow traffic and similar measures to improve road safety and increase environmental protection.
The most noticeable feature of the NEPP is the way that its individual measures reinforces each other, to produce an integrated package which links environmental, transport and land use policy. Yet even this impressive, comprehensive approach comes nowhere near solving the problems. Without the NEPP, car-kilometres had been expected to rise by 72 per cent over the period 1986-2010.
With the NEPP this increase is lowered to 48 per cent, a worthwhile reduction but still a very long way from a sustainable level of transport use. The NEPP must be seen only as the first stage in a long-term drive towards sustainability: it serves to illustrate what a difficult task lies ahead of the Dutch (and indeed all motorised countries).
Transport Policy in UK:
Due to geographical conditions, UK always remains very particular regarding its transport development and policy. Since 1945, UK has done considerable changes in its transport policy.
In general, three particular phases can be distinguished:
(i) 1945-51: The genesis of nationalised transport sector, with increasing regulation in order to restrict competition, coordination of transport services was envisaged through state (i.e., common) ownership.
(ii) 1951-68: A gradual relaxation of regulation and control, with the aim of allowing natural tendencies to determine the direction of transport policy.
(iii) 1968-77: Coordination through competition remains foremost, but more resources have been allocated to propping up and rationalising an ailing public transport sector.
The notable points of UK’s transport policy (1970) are:
(i) The transport infrastructure and services (rail, road, ports, etc.) must be modernised. Since total resources are limited, this means planning investment as a whole, increasing productivity and developing better criteria to assist choice.
(ii) The problem of traffic conditions in towns must be given greater priority,
(iii) The transport system must take account of the social as well as economic needs of the country.
(iv) Public transport must play a key role in solving the transport problems.
Five areas of concern are also identified:
(i) There is still no proper framework for the effective coordination of transport policy,
(ii) The social problem of ensuring adequate public transport for those without cars is becoming more pressing.
(iii) Concern for the environment and the quality of life has increased dramatically in recent years.
(iv) The energy crisis of 1973 has necessitated a revision of car ownership forecasts.
(v) Overshadowing all the above developments is the need for public expenditure restrictions.
Following Britain’s accession to the EEC in 1973, the transport policy has also been changed accordingly but its basic features remained the same.
Example of the European Union (EU):
The EU has not yet been able to evolve a common policy for the development of transport. Within the EU there are differences between members states in their philosophical position towards transport, with the ‘Anglo-Saxon’ approach focusing on economic efficiency and contrasting strongly with French-German-Scandinavian attitudes in which efficiency is more usually seen as secondary to the wider role of transport within economic and social planning.
This conflict between the interests of member states produces an unstable policy environment and one which is far from ideal for the task of producing profound insights or long-term goals. There are further complications as a result of the fact that the EU does not form a contiguous geographical space, with Greece physically separate and routes having to pass through third-party countries such as Switzerland in order to connect two members such as Germany and Italy. Not surprisingly, by the time the Single Economic Market (SEM) came into existence in 1993 a common market in transport still had not been achieved.
The main policy objectives at the European level are now:
i. An economic and regulatory framework for transport, including harmonisation of fiscal policies and fair comparison and assessment of different transport projects;
ii. New research and development initiative;
iii. Standardisation and technical regulation, e.g., road pricing technology;
iv. Development of trans-European networks; and
v. Information exchange, including better quality transport statistics, which will assist the objective of ‘sustainable mobility’.
Policy for Sustainable Transport:
Sustainable means “that meets the needs of the present without compromising the ability of future generations to meet their own needs”.
For transport to be sustainable, it must satisfy three basic conditions:
(1) Its rates of use of renewable resources do not exceed their rates of regeneration;
(2) Its rates of use for non-renewable resources do not exceed the rate at which sustainable renewable substitutes are developed; and
(3) Its rates of pollution emission do not exceed the assimilative capacity of the environment.
The following guiding principles have been listed by
Withelegg (1993) for sustainable transport development:
(1) Transport is a vital element in economic and social activities but must serve those activities rather than be an end in itself.
(2) The consumption of distance by freight and passengers should be minimised as far as possible whilst maximising the potential for locally based social interaction and locally based economic activity.
(3) All transport needs should be met by the means that is least damaging to the environment.
(4) There should be a presumption in physical land use planning against those activities, which by nature of their size and importance attract car-based users from a large area.
(5) All through investment plans should be subjected to a full health audit notwithstanding the uncertainties surrounding epidemiological proof. Proposals which are potentially health damaging should be rejected.
(6) All transport investment plans should have clear objective designed to cover social, economic and environment concerns and be evaluated by an independent authority with sufficient expertise to comment on value for money, costs and benefits and the availability of alternative strategies to achieve the same objectives.
(7) All transport investment should be monitored over their lifetime to check on the degree to which they meet their objectives and their contribution to environmental damage.
(8) All transport policy matter should be dealt with in a transport policy directorate that has no direct responsibilities for the management of individual modes. The responsibilities of the directorate are to deliver sharply focused polices that minimise danger, minimise air and noise pollution, maximise social interaction and urban quality of life and oversee the non-policy-making executives (for road, rail and air) whose role is to implement the directives of the transport policy directorate (Whitelegg, 1993:157). These principles would represent a starting-point for a new approach to transport policy and set out an agenda for transport planners.