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Critical factors for an effectiveand efficient multi‐modal freighttransport network in EuropeKostas Bithas a & Peter Nijkamp ba Lecturer at the Department of Regional Economics ,Panthios School of Economics and Political Science , Athens ,Greeceb Professor of Regional Economics at the Department ofRegional Economics , Free University , De Boelelaan 1105,Amsterdam , 1081 HV , The Netherlands E-mail:Published online: 24 Jan 2012.

To cite this article: Kostas Bithas & Peter Nijkamp (1997) Critical factors for an effective andefficient multi‐modal freight transport network in Europe, Innovation: The European Journal ofSocial Science Research, 10:3, 243-258, DOI: 10.1080/13511610.1997.9968530

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Innovation, Vol. 10, Ko. 3, 1997 243

Critical Factors for an Effective and Efficient Multi-modalFreight Transport Network in Europe

KOSTAS BITHAS & PETER NIJKAMP

ABSTRACT This paper analyses the European freight transport network from the viewpoint of itsefficiency in overcoming severe barriers. Based on a broad overview of modern issues in European transportpolicy, the paper identifies various bottlenecks—at both national and European levels. Based on a surveyamong European transport experts an assessment of the importance of these barriers is made, using roughset analysis. In this way the critical success factors for an effective and efficient multi-modal Europeannetwork can be identified.

Introduction

The aim of an integrated European Community is—apart from many economic and poli-tical desirabilities—strongly connected with transport potentials within Europe. Besides,transport is to a large extent responsible for environmental, accessibility and other exter-nality problems; the relevant current trends are not promising for overcoming these prob-lems.

In this respect, the development of a (more) efficient and effective Trans European trans-port Network (TEN) is of great importance. The development of such a network is inclu-ded among those activities emanating from the European Commission's White Paper onGrowth, Competitiveness and Employment endorsed by the Heads of States and Govern-ments in 1993. The overall vision regarding the development of these networks is colour-ed by the concept of multi-modality. This has particular relevance for the freight sector inEurope.

Freight transport absorbs a considerable share of the total transport activities. Further-more, freight transport is of tremendous importance for the creation of an effective andefficient single European market. This is also witnessed by the fact that international freighttransport has risen more than 100/o annually in the past years.

In recent European transport policy, a great deal of attention is given to sustainabletransport and intermodality. But the way towards real value added networks based oninteroperability, interConnectivity and integrated logistic chains is still long and full ofobstacles, as it encounters institutional inertia in its goal of competitive action in the trans-port market.

The current Common European transport policy has three main objectives. In the firstplace, the development of a Trans European Network should be stimulated, a policy whichshould favour the development of peripheral regions. Second, transport markets shouldbe liberalized to die maximum extent possible; market regulations should be equal in eachmember state and product markets would have to be opened for agents of each country.Finally, the transport sector should aim at achieving sustainable mobility.

It is interesting that nowadays the transport function is shifting away from a purely

1351-1610/97/030243-16 ©1997 Interdisciplinary Centre for Comparative Research in the Social Sciences

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244 K. Bithas if P. Nijkamp

physical shipment of goods and persons to a value added process through which in eachstep of the chain new services and economic values are added (for instance, assembly innodal points, service delivery to train passengers in railway stations). This often implies atransformation into goods or services of a higher market value. An illustrative example isthe modern component assembly industry, where components are produced in low wageor cheap resource countries (primary production) and the final product is assembled—after many transport activities—as close as possible to the final market (secondary produc-tion). It is foreseen diat value added logistics will increasingly become a major feature ofa modern post-Fordist industrial nation. Consequently, central nodes of a transport systemtend to become places of strategic importance. As a result, the quality of the organizationof transport as a material and immaterial process chain through links and nodes is be-coming the new competitive feature of modes in a transport system.

In diis framework the present study examines the conditions for developing an efficientand effective multimodal freight transport system which may also offer a relief to thecurrent environmental and transportation problems in Europe. Our study will examinethe concept of multi-modal transport for the case of combined road-rail transport. Anoperational framework for the evaluation of the current state and performance of thisnetwork will be developed. In our empirical work, a survey questionnaire is used to identi-fy the main barriers that constrain the development of an effective and efficient multi-modal (rail-road) freight transport network in Europe. The survey contains views oftransport experts from all European countries. The paper is concluded with some strategicremarks on a European transport policy.

New challenges to the transport sector

European integration emerges as a challenge for policy making on social cohesion andeconomic efficiency in the European and international context. Transportation is an activityof decisive importance for both social and economic objectives. Passenger transport isstrongly related with socio-cultural exchange and development, while commodity shipmentis strongly oriented towards economic development in Europe. Transportation of goodsand passengers forms a cornerstone activity on the way towards a single European market(Button and Banister, 1990). As the European territory expands by the integration of newcountries and as a greater variety and magnitude of raw materials and products are expectedto move within diis territory, freight transport is going to be either a decisive promoter ora strong barrier to an efficient common market. The direct user's transport costs as wellas the relevant hidden costs (bottlenecks, congestion, etc.) determine to a considerableextent the costs of production and of distribution processes and hence the competitivenessof the European market. In addition, these factors also co-determine the economic effective-ness of the regional economies widiin Europe and hence future European development.Furthermore, freight transportation is going to influence the question whether 'national'firms will become European firms by realizing the concept of die 'extended firm', exploringthe comparative advantages of each member country (Nijkamp et al, 1993).

In the past, freight transport was based on railways because of the relative advantagesof this mode compared to road. Indeed, during the latter part of the last century die railinfrastructure was considerably extended and was for many years more reliable whencompared to the road system. The rail infrastructure also served odier social purposes,e.g. national defense. At the same time, transport demand was well met by die railwaysystem. Indeed, the main goods to be transported were raw materials of low value orheavy final products. As the western economies moved towards a service and post-indus-trial economy, transport demand changed drastically. Light products of high value, just in

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Critical Factors for a Freight Transport Network 245

time production, decreasing stock size etc. appeared to require a different type of transportmode. Over the post-Second World War period, the road mode had developed an exten-sive infrastructure which permitted a flexible, speedy, reliable and cheap operation. There-fore, road transport has been increasing its share in freight transport in recent years (Euro-pean Conference of Ministers of Transport, 1992).

Nowadays, the freight characteristics are changing towards valuable and sophisticatedproducts, express delivery, door-to-door delivery, etc. So, the transport sector is no longera single economic activity-agency. It takes the form of a chain of 'value added' activitiesthat are performed by different actors who utilize the existing infrastructure and offer areliable service that the user is willing to pay for. It is worth mentioning here that theinfrastructure expansion and the restructuring (both in infrastructure and in operation)of transport supply create a new demand in the sector, as we can observe from recentrelevant trends.

Technical developments in the transport sector in recent years may be characterized asan important driving force. New infrastructure opportunities which can result in attractivetransport properties are realized, for example, magnetic lévitation, high speed trains, vacu-um tunnels, etc. In transport operation, the use of informatics can create new prospectsfor decreasing the cost and increasing speed and reliability, for example, telematics, newsignalling methods, energy saving measures, etc. However, although these developmentsseem promising, they have not yet been introduced other than in experimental modes,and their outcomes depend strongly on die current transport policy (EC, 1994).

On the other hand, transport is strongly related to severe problems in our present soci-ety. The most important disturbance is environmental decay. Indeed, transport contri-butes to a considerable degree to both air pollution at the local level and global warmingat die global level. In addition, the increase in total energy consumption depletes the neces-sary but limited resources of our world. At the same time, serious amenity disturbancescan be envisaged, for example, noise, ecosystems separation, land requirements, sight-amenity disturbances etc. It seems that the severity of these problems calls for direct andimmediate action. In this context, several European countries are designing a number ofregulatory and economic counter-measures (Austria, Germany, France, etc.). These meas-ures tend to impose barriers to freight transportation that may affect its economic profita-bility. In addition, the inevitable problem of road congestion on important European corri-dors deteriorates an efficient transportation operation. All these issues call for a concreteand coherent European transport policy (Group Transport 2000 Plus, 1991). Otherwise,the emerging inefficiency will lead to cost increases which will hamper the efficient func-tioning of die single market, while on the other hand the external problems will be intensi-fied. Indeed, it seems necessary diat a European freight transport policy has to be design-ed. In diis context, a new institutional framework for increasing efficiency may emerge,whose main characteristics are as the following. Deregulation and privatization are increas-ingly promoted for rail transport; this mode should pass from bureaucratic managementto market oriented operation. In addition, a single national orientation of each rail opera-tor is discouraged. In this course, the separation of the railway infrastructure from its ownoperation is pursued, which is a necessary condition for a free entry market ('contestablemarket'). As far as road is concerned, diis policy may promote the internalization of thenegative external costs via die application of die 'user pays' principle and the like.

In die present study, die intriguing question from die above perspective is to define dienecessary and sufficient conditions for a satisfactory freight transport network in Europe.A network is defined here as a cohesive set of infrastructure links (edges) connectingconcentrations of people or economic activity centres (so-called nodes), with a view onthe utilization of diese infrastructure links by transport actors. As noted above, the present

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246 K. Bithas & P. Kykamp

study is mainly concerned with the rail-road multi-modal freight transport network (Nij-kamp and Blaas, 1994).

There are three main characteristics of such a network. First, the interoperability whichrefers mainly to operational and technical uniformity which allows actors and operatorsto use a network for different simultaneous or sequential purposes. Second, the inter-connectivity which is in particular concerned with horizontal coordination and access tothe network from different geographical areas. And thirdly, the intermodality which ad-dresses the issue of a combined use of different transport modes in the chain of freighttransport (Nijkamp and Blaas, 1994; Nijkamp etal, 1993).

The present study aims first to evaluate the current state of the rail-road freight networkin Europe and then to trace the properties of a satisfactory network and finally to definethe relevant necessary and sufficient conditions. In this perspective, the study adopts aEuropean view on infrastructure networks as seen by relevant decision-makers who haveto design a policy towards the improvement of the present system. The network will beassessed over three main dimensions: environmental, economic and services (customers'satisfaction). Instead of a maximization process in one dimension, a trade-off will be adop-ted, since competitive elements between these issues are involved.

The main background issues diat are taken into account in our study are die following:

(1) die severe environmental problems caused by current road-rail freight transport oper-ation should be systematically considered and taken into account when die character-istics of a satisfactory system are examined;

(2) die crucial technical, managerial and institutional barriers should be identified, dieirrelative importance assessed, and their removal should be favoured, so that the evolu-tion of the system would be able to favour a more environmentally sustainable be-haviour;

(3) the service delivered by die network should be sufficient, according to die currentEuropean market conditions and die relevant desired evolution as well—die institu-tional framework of rail operations would have to be re-oriented towards a businessactivity which produces diose services die consumer desires;

(4) it seems at first glance diat rail and road are by definition competitors and will main-tain diis relationship in die future, but a tentative evaluation of die network mayreveal possibilities for synergy diat create mutual benefits to them and increases theoverall efficiency of the whole system. The potential for such a synergy will be tracedin die study. The relevant barriers will be examined on institutional, managerial andtechnical grounds.

For studying the rail-road freight transport network some important aspects of eachmode should be examined; diese aspects may be considered as 'rational principles' diatunderlie the function of each mode and dierefore, diey should be taken into account byrelevant policy-makers (Nijkamp and Blaas, 1994). These aspects are:

• performance: value added; distribution of benefits• synergy with other mode(s): cohesion; scale; morphology• buyers' market: customer driven; motives; internationalization• capacity limits: echnomax; enviromax; sociomax; perimax; terminomax• multi-actors' market price/quality ratio; typology of actors• tarification: transport as commercial market; clean pricing policy; economic instru-

ments; market for transport (e.g. permits)• information for policy design: data collection; data processing; data monitoring; modelling;

scenario design; policy experiments

The above issues call for further empirical work. This will be elaborated below.

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Critical Factors for a Freight Transport Network 247

Methodology to be used

Prefatory remarks

Erst, in our paper, an operational methodology for the evaluation of road-rail freighttransport operation will be established. This methodology aims at the following targets:cross-national, international and intra-national evaluation of the characteristics and per-formance of each mode and the system as a whole; and the performance and the charac-teristics of the network will be viewed from various main angles: environmental, economicand service/network appropriateness (interoperability, interConnectivity, intermodality).

For performing the above tasks, the methodology should be able to deal with differentinformation in form, in precision and in measurement scale. Indeed, the information usedin our study originates from some 20 different countries, but not all data are fully com-parable. In this perspective, the time and the cost constraints in building up a data baseshould be taken into account.

In this context, the evaluation framework boils down to a number of indicators whichserve to operationalize these concepts. The indicators fulfill some prerequisites: relativeease of data collection; relative ease in application; easily understood by policy-makersand the public; ability to be reversible; sensitivity to controllability

Evaluation of the current performance and state

The above described evaluation framework will be applied for assessing die efficiencyand die state of each mode separately and of the network as a whole. This will be pursuedat two levels. First, the technical elements and their operational aspects will be evaluated.Secondly, the operational-managerial characteristics will be considered. In effect, the cru-cial relative advantages and disadvantages of each mode will be identified and assessedand the relevant trends will be assessed. This approach leads to die determination of thecharacteristics (environmental, economic, service/network) of a 'good' or satisfactorilyoperating freight transport network. Such desired trends will be defined for each modeand for the entire system. The aim of a good network addresses the issue of the desiredrelation between the two modes directly; should diey collaborate or compete, and to whatextent? The information diat will be used at this stage of die study originates from existingEuropean statistics as well as from a questionnaire addressed to a broadly composed panelof transport experts in Europe.

Identifying and assessing the current barriers and success factors

In this step die study will trace, identify and assess die decisive barriers that prevent awell-functioning operating of die freight road-rail network. These factors will be tracedat two levels: at die supply side and at die demand side. The issue of achieving a satisfac-tory freight transport network will be examined. For designing die necessary policy diecrucial success factors have to be carefully studied and dieir relative importance system-atically assessed. For die identification of bodi current barriers and success factors the so-called pentagon model will be used. This model distinguishes the relevant barriers intofive main categories: financial, organizational, hardware, software and ecological barriers(OECD, 1992; Nijkamp and Blaas, 1994).

The evaluationfiamework fir the current performance and state of wad-rail freight transport

Freight transport, and transport in general, is a logistic system performing a specific econ-

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248 K. Bithas dr P. Mjkamp

omic task that is useful for individuals and society as a whole. This man-made systemoperates in the environmental, economic and institutional framework of society and it isinterrelated with other man-made and natural systems. In physical terms, the systemobtains some inputs from the 'surrounding' systems and gives back some outputs. Thus,materials, energy, capital and human capital enter the system as input, while various ser-vices—accompanied by some useless output—return to the 'surrounding' system. In econ-omic terms, the system operates in the framework of the economy and has its own micro-and macro-economic characteristics. They determine respectively its economic perform-ance and its importance for the whole economic system. In institutional-social terms, diesystem functions in accordance with the dominant rules of society, a situation which gen-erates specific properties in both its operation and its outcome. Simultaneously, its out-come can be evaluated for its social appropriateness (OECD, 1992).

An evaluation framework should consider all such physical, economic and institutionalperspectives of the system. An ideal evaluation would be to define a reference point orbenchmark by means of which the system might be characterized as 'good'. This mightalso be done separately for the main aspects of the system. However, such an absoluteevaluation is hardly achieved in open, partial and small systems.

Therefore, by necessity an evaluation framework based on the relative assessment ofthe system has to be adopted. For the freight transport sector, we cannot define reference-point levels at which the system can be said to be environmentally sustainable, economic-ally efficient and socially appropriate. AU we can do is to assess the relative environmental,economic and social performance of the system. Relative evaluation means to comparethe system's performance with the respective performance of another system of a similartype or with its performance in die past or future.

The performance of the freight transport (rail-road) system can be evaluated at twodistinct levels: economic efficiency and state indicators. The two concepts will be dis-cussed here. The system obtains material and energy inputs, as well as labour and capitalservices from outside. It results into useful output (transport service) and some materialand energy waste (pollution). The efficiency of the system is defined by the productivityincrease through which it utilizes its inputs in order to create die useful output, and by therate of reducing the waste production as well. At this point, we can distinguish two classesof efficiency: environmental and economic efficiency. Environmental efficiency regardsthe relative environmental friendliness of the sector. It examines both the exploitation ofnatural resources and environmental degradation.

Resource exploitation is related to energy and material inputs. So, the relevant efficiencyshould consider the relationship between these inputs and the useful outcome of the sec-tor. Environmental degradation refers to die waste pollution produced during die system'soperation. Thus, die relevant efficiency is assessed on die basis of die relationship betweenuseful outcome and useless waste. It goes widiout saying diat environmental efficiency ismeasured by quotients whose numerator is expressed in physical terms and the denomi-nator in output (service) units which can be eidier monetary units (value of transport) orphysical units (ton-km). Economic efficiency can be assessed via die productivity of allinputs diat have an economic cost. As a whole, in die economic domain we use die conceptof die marginal cost per unit of output to define die economic efficiency of the system,since die marginal cost takes into account the systemic change. It is a generally acceptedmeasure, as far as we exclude externalities from our framework.

The evaluation of the state of die system should reveal its main characteristics, proper-ties and capacities. In general, the main characteristics can be classified into diree groups:environmental, economic and services. In our study, die service characteristics should alsoaccount for die network performance of the system. Obviously, the system's state be

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Critical Factors for a Freight Transport Network 249

assessed in absolute terms, while the three main aspects of the system will be accountedby absolute measurement. We are interested in die state of the system, since the statereveals some important properties which co-determine its evolution and performance.Note that diese properties can not be assessed when die efficiency of die system is exam-ined, since in diat case some crucial absolute magnitudes vanish via die use ratio measure-ments. The three main aspects of the system (environmental, economic, service) can alsoreflect the respective environmental, economic and social effects, arising from the system'sfunction. As a result, this evaluation basis leads to a number of indicators that are able tosystematically operationalize it; indicators reflecting die efficiency of die system will havedie form of ratios (quotient indicators). The numerator will be the useful outcome (trans-port service) of the system, expressed in eidier physical units or in monetary values. Thedenominator will be die natural inputs and die waste in the case of environmental effici-ency, and economic cost of the inputs in the case of economic efficiency. In fact, theseindicators form a suitable basis for analysing specific case studies, since die conditionsdiffer significandy between European countries.

Tlie evaluation framework for the barriers preventing the development of a 'desired' multi modal (rail-road) network

The identification and die assessment of die relative importance of die barriers in a trans-port system is faced widi considerable difficulties, since die relevant literature and statisticsare limited; in particular when the analysis concerns all European community countries,each one presenting particular characteristics and specific problems. Therefore, in thepresent study a survey approach will be used. It aims at identifying the crucial barriers atthe national and international European level.

Identifying the conditions of an effective multi-modal freight transport network:an expert-based approach

Description of the survey

The analysis in die previous sections indicates diat intermodal freight transport presentsconsiderable advantages in comparison to single mode transportation. The question isnow whedier multi-modal transport reaches a sufficient or desired level in Europe; and ifnot, which are the main barriers that prohibit such a development. Clearly, die directassessment of the state of multi-modal transport as well as die identification of die relevantobstacles face incommensurable problems, since both relevant studies and empirical statis-tics are scarce. In order to cope widi this problem, a survey study has been designed inthe framework of the present research. Its basis is a comprehensive questionnaire sent toEuropean experts which deals widi two issues in its respective parts. Part 1 asks for anassessment of the gap between die current intermodal transport and the correspondingdesired level. Since a critical factor for an effective multi-modal network is die existence ofintermodal terminals, Part 1 assesses also dieir present availability in relation to die respec-tive desired level. All assessments take place at both die national and the international(European) level. Part 2 deals with the main barriers preventing die development of effec-tive multi-modal transport. These barriers are classified into die five Pentagon groups:financial, organizational, software, psychological and hardware.

The questionnaire was held among freight transport experts in all Western and CentralEuropean Community countries plus Switzerland. The opinion of each expert was askedfor separately for die respective national and (European) international level. A presenta-tion of die questions and die relevant results are presented in die Appendix.

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250 K. Bithas & P. Kijkamp

Methodology

The total response to the questionnaire was 60 (response rate 75%). Clearly, this sampleis insufficient to apply standard statistical methods. Therefore, a recently developed non-parametric statistical method for data analysis is used. This is rough set analysis developedby Pawlak (1991) and Slowinski (1993). We will first give a concise introduction to roughset theory (see also Pawlak, 1982, 1991; Slowinski, 1993; Matarazzo, 1996).

A rough set is a set for which it is uncertain in advance which objects belong preciselyto that set, although it is in principle possible to identify all objects which may belong tothe set at hand. Rough set theory takes for granted the existence of a finite set of objectsfor which some information is known in terms of factual (qualitative or numerical) know-ledge on a class of attributes (features, characteristics). These attributes may also act asequivalence relationships for these objects, so that an observer can classify objects intodistinct equivalence classes. Objects in the same equivalence class are—on the basis ofthese features concerned—indiscernible. In case of multiple attributes, each attribute isassociated with a different equivalence relationship. The intersection of multiple equiva-lence relationships is called the indiscernibility relationship with respect to the attributesconcerned. This intersection generates a family of equivalence classes that is a more pre-cise classification of the objects than that based on a single equivalence relationship. Thefamily of equivalence classes that is generated by the intersection of all equivalence rela-tionships is called the family of elementary sets. The classification of objects as given bythe elementary sets is the most precise classification possible, on the basis of the availableinformation.

The indiscernibility relationship and the equivalence classes generated by this relation-ship make up the basic concepts and building blocks of rough set theory. A set is nowtermed rough if it is impossible to build it up from one or more elementary sets. In otherwords, a set is rough if it is not equal to a union of elementary sets. In this framework, twonew concepts are introduced, viz. the lower and upper approximation in order to identifya range of uncertainty for the assignment of objects. The lower approximation of a set Vis the union of all elementary sets that are a subset of V. The upper approximation of a setV\s the union of all elementary sets that have a non-empty intersection with V.

This approach leads thus to an imprecise representation of reality due to the 'granular-ity' of knowledge; in other words, reality is represented by 'granules', corresponding tothe elementary sets, i.e. subsets of the universe whose elements are indiscernible (indistin-guishable) by the set of attributes used, because they present the same description in termsof the values of these attributes. The 'granularity' of knowledge representation is used todefine the key concepts of rough set dieory. The size of diese 'granules' depends, naturally,on both the number of attributes used for the description of the objects and the domainof each attribute. With, a suitable variation in these two quantities it is possible to obtaina variation in the dimensions of the 'granules': an increase in the number of attributesand in the number of values which each attribute can assume, results in more 'granules'.

Next, lower and upper approximations can be determined on the basis of the typology('granules') generated by the available information on the elements of the relevant set(indiscernibility relation), that is, on the ability to observe some real phenomena (objects),classify them and distinguish them on the basis of the information obtained from real-world observations or of prior knowledge from an expert. The representation of realityby means of rough sets is therefore based on the knowledge (objective or subjective) onreality and the capacity to classify die information obtained.

Now we may introduce die concept of a reduct. A reduct is a subset of the set of allattributes with the following characteristic: adding another attribute to a reduct does not

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Critical Factors for a Freight "Transport Network 251

lead to a more accurate classification of objects (i.e. more granules), while elimination ofan attribute from a reduct does lead to a less accurate classification of objects (i.e. lessgranules).

finally, the core of a set is the class of all indispensable equivalence relationships. Anattribute is indispensable if the classification of the objects becomes less precise when thatattribute is not taken into account (given the fact that all attributes have been considereduntil then). The core may be an empty set and is, in general, not a reduct. An indispensableelement occurs in all reducts. The core is essentially the intersection of all reducts.

Based on the previous concepts, rough set theory is now able to specify various decisionrules of an 'if then' nature. For specifying decision rules, it is useful to represent our priorknowledge on reality by means of an information table. An information table is a matrix(objects row-wise, attributes column-wise) that contains the values of the attributes of allobjects. In an information table the attributes may be partitioned into condition (back-ground) and decision (response) attributes. A decision rule is then an implication relation-ship between the description of the condition attributes and that of a decision attribute.Such a rule may be exact or approximate. A rule is exact, if the combination of the valuesof the condition attributes in that rule implies only one single combination of the valuesof the decision attributes, while an approximate rule only states that more than one com-bination of values of the decision attributes correspond to die same values of die conditionattributes. Decision rules may thus be expressed as conditional statements ('if then').

In this way one may analyse in greater depdi die information contained in the originaltable and to enrich it, specifying additional decision rules directly by means of suitableinterviews or discussions widi experts. In other words, it is possible to acquire informationalso directly in die form of decision rules supplied by experts, diereby enriching die ori-ginal information contained in die decision table.

In practice, therefore, it is possible to use bodi the decision rules obtained by elaboratingthe data contained in die decision table and, if necessary, in furdier rules supplied andsuggested by experts. The former may be accompanied by an indicator of dieir 'strengdi',for example, die frequency (absolute or relative) of events in agreement widi each decisionrule. Moreover, both die former and the latter may be based on suitable and different setsof condition attributes, containing a larger or smaller number of attributes (even a singleattribute). This last case implies that die value assumed by an attribute is sufficient toguarantee diat the decision attribute (or attributes) will assume certain values, whateverthe values of die odier condition attributes. This consideration assumes particular import-ance when incomplete information is used, that is, when some values in the decision tableare missing or are uncertain (empty cells). Decision rules which do not use conditionattributes containing imperfect information assume particular importance in such cases,since they make it possible to operate widiout the knowledge of diese values.

Decision rules, which constitute die most relevant aspects of rough set analysis, may beapplied immediately in order to offer recommendations and advice in problems of multi-attribute sorting, that is in the assignment of each potential action to an appropriate pre-defined category according to particular aims. In dûs case, the classification of a new objectmay be usefully undertaken by a comparison between its description (values of the condi-tion attributes) and the values contained in die decision rules. These are more general dianthe information contained in the original decision table and permit a classification of newor additional objects in larger numbers and more easily than would be possible using adirect comparison between diese and die original examples. In general, such decision rulesallow to make conditional transferable inferences, as die 'if conditions specify die initialconditions, while the 'then' inference statements highlight die logical valid conclusions. Inthis way, rough set analysis can also be used as a tool for conditional transferability of

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252 K. Bithas fr P. Mjkamp

results from some case study to a new situation. The mathematics of rough set is rathercomplicated, but has been properly described in the literature (Pawlak, 1982, 1991).

Results of the rough set analysis

This section presents the results of the rough set method on the survey questionnaire ofour study. Although rough set analysis may be used for identifying decision rules andperforming multi-attribute sorting, we will rely in particular on the concepts of a reductand the core of attributes which are used in our analysis. Every expert questionnaire isconsidered as an object in die rough set method.

There are four independent variables (decision variables) :

(1) the gap of current intermodal transport to die desired level—National level;(2) the gap of current intermodal transport to die desired level—European level;(3) the gap of current intermodal terminals to the desired level—National level;(4) die gap of current intermodal terminals to die desired level—European level.

Therefore, the analysis will be subdivided into four cases, each one considering onedependent variable in relation to die relevant independent and explanatory variables. Asexplanatory variables (attributes) we consider all the remaining questions-entities of diequestionnaire. For a detailed presentation we refer to the Appendix, where all the structureof die questionnaire is given. The explanatory variables are classified into five pentagongroups: financial, organizational, software, psychological and hardware.

In all cases, diree meta-variables are added to die analysis in order to test their import-ance for die development of an effective multi-modal transport. These meta-variables arethe following: population, surface of die country considered, and die geographical posi-tion of die country (central or peripheral in die European territory).

In each case, rough set analysis examines which are die subsets of explanatory variables/barriers diat lead to the same accurate classification widi all variables considered. In diisway, reducts of barriers are estimated; each reduct presents a set of important explanatoryvariables (barriers). Next, die core of all reducts, if it exist, consists of all—and the onlyones—important barriers.

The analysis initially identifies die reducts widiin each one of die five groups of barriers(financial, organizational, software, psychological, hardware). This process indicates themost important barriers of each group. Next, die sum of die most important variables isconsidered, while next die reducts are estimated. These reducts and die respective core, ifthey exist, may be interpreted as important barriers.

The gap between existing and 'desired' intermodal transport at the national level

The independent variable is the gap between existing intermodal transport at die nationallevel in relation to die relevant 'desired' level; in roughset theory terms diis is die classifica-tion/decision variable. So each expert's opinion is classified into one of the five groups(non-existing gap, very small, small, high, extremely high) according to his answer to thedependent variable. In order to identify die relative importance of each barrier variablefor die classification of die answers, which in fact means to identify die relative importanceof each barrier for die gap between existing intermodal transport at die national level andthe relevant 'desired' level, we apply rough set analysis. First, we examine die relativeimportance of each group of barriers (financial, organizational, psychological, software,hardware, meta-variables) as a whole and then we examine die relative importance of thebarriers widiin each group.

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Critical Factors for a Freight Transport Network 253

The group of financial barriers has a relatively high importance for the classification,since the barrier variables of this group alone suffice to give an accurate classification ofhigh quality—they form a reduct in rough set analysis. In reality this means that the finan-cial barriers are a critical obstacle for the development of an effective intermodal freighttransport at the national level. Within this group the relative importance of the 'user costin intermodal transport' and the 'user cost at intermodal terminals' are very high, althoughdiey do not form a reduct in rough set analysis. The 'investment cost of intermodal infra-structure' and the 'investment cost of rail infrastructure' follows with a relatively lowerimportance which nevertheless remains at a considerable level. It is notewordiy that inrough set analysis diere is no core of attributes/barriers within the financial group.

The group of organizational barriers has also a high importance, since the organiza-tional barriers separately lead to an accurate classification of high quality for the objects:they form a reduct in rough set analysis. As far as the relative importance within this groupis concerned, we may conclude that the 'institutional barriers which prevent intermodaltransport between different countries' and the 'bureaucratic organization and manage-ment in rail mode'are the most important barriers. The 'lack of express delivery in inter-modal transport' and the 'lack of just in time delivery in intermodal transport' are ofsecondary importance. Wfe note that diere is no core of attributes/barriers within the or-ganizational barriers group.

Next, both the groups of software and psychological barriers, when considered indi-vidually, appear to have a very low importance, similar for both groups, and thereforetheir explanatory power for the classification of the objects is low. If these groups areconsidered together, then their importance increases; however, it still remains far lowercompared to die financial and organizational groups; still they do not form a reduct inrough set theory.

The group of the hardware barriers is of great importance, since this group alone leadsto an accurate classification of the objects: the barriers of this group form a reduct in roughset dieory. It turns out that among the variables of this group the most decisive barrier isthe 'lack of intermodal terminals'. The 'lack of rail infrastructure' dien follows, while dieremaining barriers have almost the same lower importance.

Finally, the group of the meta-variables appears to have die lowest importance amongall groups. At this point of our analysis, we are able to select the most important barriervariables of each group and to check their importance at a more general level. It appearsthat the financial and hardware barriers are the most important ones. Specifically, die 'lackof interoperability of railways at the European level' alone, die group of'investment costsfor intermodal infrastructure' together with 'investment cost for rail infrastructure' andthe group of die 'user cost at intermodal terminals' together with die 'user cost in inter-modal transport' appear to be the most decisive ones. It is note wordiy that diere is nocore of attributes neidier for the whole set of attributes considered nor for the set of themost important ones.

Another general conclusion, which may be drawn from the analysis up to this level, isthat the barriers prohibiting die development of an efficient intermodal freight transportat the national level differ considerably between countries. It seems diat the decisive mix-ture of variables is different in each country. For instance, in one case we find diat diefinancial barriers together widi software barriers prevail, while in another case a combina-tion of hardware together widi organizational barriers is die main obstacle.

Neverdieless, die analysis up to this point indicates that die importance of hardwareand financial barriers are die most common and severe obstacles for the development ofan effective and efficient intermodal freight transport at die national level.

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254 K. Biihas if P. JTykamp

The gap between existing intermodal and 'desired' transport at the European level

In this second step of our analysis, the independent variable is the gap between the existingintermodal transport in relation to the 'desired' level, at the international (European) level;in rough set theory terms, this variable stands for the classification/decision variable. Thequestion now is to identify the relative importance of die independent variables/barriersfor the classification. This, in turn, means to identify the contribution of each barrier inthe gap. Following the same mode of analysis as in the previous section, the importanceof each group of barriers is examined separately.

The group of financial barriers leads to a classification of high quality and therefore itpresents a relatively high importance: the barriers of diis group form a reduct in rough settheory. The most important barrier variables are the 'investment cost for rail infrastruc-ture', the 'investment cost for intermodal infrastructure' and the 'user cost in rail mode'which form also the core of the attributes-barriers according to rough set analysis (Slowin-ski, 1993).

Next, the group of organizational barriers alone can not establish an accurate classifica-tion and hence is of secondary importance: these barriers do not form a reduct. Neverthe-less, among the barriers of this group, the barriers 'lack of express delivery in intermodaltransport', 'lack of just in time delivery in intermodal transport' and 'delays at intermodalterminals' appear to emerge with the relatively highest importance.

The group of software and die group of psychological barriers also appears to have arelatively low interest. Even when bodi groups are examined togedier, they do not lead toan accurate classification of die objects, and dierefore dieir explanatory power is low.

The hardware group clearly has a high explanatory power: die barriers of this groupclearly do form a reduct. The barrier 'lack of interoperability of railways at the Europeanlevel' appears to be die most interesting. The subgroup consisting of die barriers 'lack ofspecific rail vehicles suitable for intermodal transport' togedier widi 'lack of specific trackvehicles suitable for intermodal transport' offers a considerable explanatory power, whilethe barrier 'lack of rail infrastructure' comes third in the importance ranking.

At diis point we are able to select die most important variables from all groups and toexamine die relative importance between diem. It appears that die barrier 'lack of inter-operability of railways at die European level' is die most decisive one, while the barrier'investment cost for intermodal infrastructure' and 'investment cost for rail infrastructure'follows next. The barriers 'lack of specific rail vehicles suitable for intermodal transport','lack of specific track vehicles suitable for intermodal transport' and 'lack of rail infra-structure' have also a high importance.

Consequendy, it appears diat die most powerful explanatory barrier variables belongto die groups of hardware and financial barriers. This result is more evident at the inter-national (European) level compared to die national ones. Moreover, in contrast to thenational level it seems that die prohibitive obstacles for the development of a Europeanintermodal freight transport network are perceived to be radier common at the Europeanlevel.

The gap between the existing and 'desired' intermodal terminals at the national level

It is an almost common perception among the European scientists and the experts diatdie role of the intermodal terminals is decisive for die development of an effective multi-modal freight transport system. In diis context, die dependent variable is die gap betweendie existing intermodal terminals in relation to die 'desired' level, at die national level.Then, we have to explain die existence of diis gap by die relative power of the relevant

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Critical Factors for a Freight Transport Network 255

barriers as explanatory variables. We apply the same type of analysis as in the previoustwo subsections.

It should be mentioned at the outset diat no group of barrier variables alone leads to anaccurate classification. Therefore, the identification of the most decisive barrier shouldtake place at a general level where all variables are considered simultaneously. By applyingrough-set analysis, it appears that the most important barriers are related to financial andhardware issues. Specifically, the 'lack of suitable rail infrastructure' and the relevant in-vestment costs composed of 'investment cost for rail infrastructure' and die 'investmentcost for intermodal terminals' emerge as the most serious prohibitive barriers.

In contrast to an intuitive expectation, our analysis shows that the meta variables (popu-lation, surface, location of the country) show up as irrelevant factors. It is also noteworthythat the mixture of the decisive barriers differs significantly between countries (our rough-set analysis results in a weak accuracy of classification when a subset of barriers isexamined).

The gap between existing and 'desired' intermodal terminals at the European level

Here, the dependent variable is the gap between existing intermodal terminals in relationto the 'desired' level, at the European level. The problem of explaining this variable onthe basis of the relevant barriers, functioning as the explanatory variables in our analysis,is dealt with in the same way as in the previous part of the analysis.

The financial and hardware barriers, considered together, give an account for the lackin the development of intermodal terminals at the European level. Specifically, the 'lack ofrail infrastructure' and the 'lack of interoperability of railways at die European level' emergeas die barriers with the most decisive power. Similarly, the financial barriers 'investmentcost for rail infrastructure' and 'investment cost for intermodal infrastructure' stand forstrong barriers. We also note diat the above mentioned four variables offer a classificationof the same accuracy as die classification resulting from all variables: they form a reductin rough set dieory terms. Besides, the organizational barriers 'institutional barriers whichprevent intermodal transport between different countries' and 'bureaucratic organizationand management of railways' give a significant explanation for die classification and there-fore diey may be considered as important barriers.

In uiis framework, we may conclude diat at die international level die analysis, concern-ing the lack of intermodal terminals, leads to more rigid results in comparison widi diesame analysis at die national level, since die experts consider diat there exist commonbarriers at the European level. In diis respect, rough set analysis leads to a better approxi-mation of die relevant classification compared to die analysis at the national level.

Concluding remarks

The development of a well functioning multi-modal transport framework emerges as apromising solution for several current transport problems and relevant externalities.However, it appears diat the existing state of multi-modal networks is lagging far behindthe desired level, especially in die case of road-rail co-operation. The survey exerciseperformed in die framework of the present study thus clearly shows that transport ex-perts in Europe attach a high desirability to die development of an efficient and effectivemulti-modal network, which will be beneficial to die transport sector and society as awhole.

However, diis evolution is burdened by serious obstacles. It seems that diere are prohibi-tive financial, technical, organizational and odier problems. Especially, the co-operation

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256 K. Bithas 6- P. Nijkamp

level between European countries for the development of a fully interoperable railwayssystem is rather weak at present. And railways have to play an important role in the devel-opment of an effective network. Also, other technical problems, related to die existence ofspecific rolling material emerges as decisive barrier and should be taken into account.Besides, financial issues involved in die creation of sufficient rail infrastructure and inter-modal terminals seem to be a radier prohibitive obstacle in almost all European countriesand relevant institutions.

On the other hand, the importance of proper intermodal terminals is considered asfundamental by most European experts. They indicate that diere is a great lack of inter-modal terminals which could facilitate an effective rail-road network. The developmentof proper terminals is also burdened by serious financial and intra-European co-operationobstacles.

In diis context, our final recommendations emerging from our study concern the devel-opment of a policy for removing the financial and hardware technical barriers, since multi-modal freight transport emerges as a promising evolution in economic, social and environ-mental terms. Such a policy may have a European (international) perspective which takesinto account die particular national characteristics in each country. In diis framework, theadoption of common technical standards for railways operation and die introduction ofnew financial schemes emerge as prerequisites. On die other hand, such developmentsrequire new legislation and social adjustments concerning the market structure, the man-agement and the ownership in the transport sector.

In conclusion, in die light of die capacity of die current European networks for com-modity transport in an integrating economy and in the light of the unacceptably highenvironmental stress of road transport, new logistic systems based on combined transportas a blend of different modalities are necessary. This will increase capacity, reduce conges-tion and environmental decay, and make die European network economical by itself,but—as argued in diis paper—diis requires dedicated policy strategies on bodi intermodaltransport and on transhipment terminals.

References

Button, K. and Banister, D. (eds) (1990), Transport in a Free Market Economy, London, Mac-millan.European Conference of Ministers of Transport (1992), Statistical Trends in Transport 1965-1988, Paris, ECMT.Group Transport 2000 Plus (1991), Transport in a Fast Changing Europe, DG VII, Brussels,European Community.EC (1994), Road Freight Transport in the Single European Market, Report of the Com-mittee of Inquiry, Brussels, July 1994Matarazzo, B. (1996), 'Basic principles of rough set analysis', in Nijkamp, P., van denBergh,J. C. M.J . and Pepping, G. (eds) Meta-Analysis of Environmental Strategies and Policies ata Meso Level, Brussels, European Commision Report.Nijkamp, P. and Blaas, E. (1994), Impact Assessment and Evaluation in Transportation Planning,Boston/Dordrecht, Kluwer.Nijkamp, P., Vleugel, J., Maggi, R. and Masser, I. (1993) Missing Transport Networks in Europe,Aldershot., AveburyOECD (1992), Advanced Logistics and Road Freight Transport, Paris, OECD.Pawlak, Z. (1982), 'Rough sets', International Journal of Information and Computer Sciences, Vol.11, pp. 341-356.Pawlak, Z. (1991), Rough Sets, Theoretical Aspects of Reasoning About Data, Dordrecht, Kluwer.

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Critical Factors for a Freight Transport Network 257

Slowinski, R. (ed.) (1993), Intelligent Decision Support. Handbook of Applications and Advances ofRough Sets Theory, Dordrecht, Kluwer.

Appendix. Tables of data and results

Table 1. Survey of the results

Crucial barriers Medium barriers Low barriers

Gap between existing and'desired' intermodal transport.National level

Gap between existing and'desired' intermodal transport.European level

Gap between existing and'desired' intermodal terminals.National level

Gap between existing and'desired' intermodal terminals.European level

financialHardware

FinancialHardware

FinancialHardware

FinancialHardware

Organizational

Organizational

SoftwarePsychologicalMeta-variablesOrganizationalSoftwarePsychologicalSoftwarePsychologicalOrganizationalMeta-variablesSoftwarePsychological

Table 2. Frequencies of dependent variables

Current intermodal transportcompared to the desired levelNational European

Current intermodal terminalsNational European

Non-existingVery smallSmallHighExtremely high

02

1028

3.5

00

122210

23

16188

00

122210

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Table 3. The questionnaire and relevant answers (in percentages) toenoo

bs

No (barrier) Light Intermediate Strong Extremely strong

Financial barriersIntermodal infrastructure investment costRail infrastructure investment costUser cost at intermodal terminalsUser cost in intermodal transportUser cost in rail transportOrganizationalLack of express delivery in intermodal

transportLack of just in time delivery in intermodal

transportDelays at intermodal terminalsInstitutional barriers preventing intermodal

transport between different countriesBureaucratic organization of rail modeSoftwareInsufficient informatics system in rail mode 2.4Insufficient informatics system used by

freight transport operatorsPsychologicalUnjustified prejudice against rail modeJustified prejudice against rail modeHardwareLack of intermodal terminalsLack of rail infrastructureLack of specific rail vehicles suitable for

intermodal infrastructureLack of specific truck vehicles suitable for

intermodal transportLack of interoperability of railways at the

European level

2.32.34.84.87.1

9.5

2.32.4

7.52.4

2.4

2.4

152.4

714

7.3

17.1

5.4

4.84.82.4

9.3

4.7

9.52.4

15.44.9

11.9

4.9

17.1

2.3

18.620.91921.428.6

26.2

23.331.7

2016.7

29.3

26.8

2517.1

23.320.9

48.8

41.5

16.2

27.920.923.81942.9

18.6

16.326.8

9.57.1

29.3

26.8

17.912.2

20.928.6

41.5

34.1

7

39.530.252.452.438.1

37.932.652.45731

25.630.2191926.2

23.332.614.316.723.8

26.2 44.2 28.6 20.9

1416.34.82.40

9.5

11.616.32.42.4

27.922

32.519

36.6

39

3539

25.634.9

24.4

19.5

24.3

30.236.6

38.133.3

31.7

41.5

4146.3

44.223.8

34.1

31.7

27.9

30.234.1

2535.7

14.6

22

1522

32.620.9

9.8

19.5

37.8

39.526.8

23.821.4

26.8

29.3

15.424.4

27.931

14.6

17.1

37.2

16.39.8

1526.2

17.1

9.8

1019.5

11.69.3

9.8

2.4

16.2

9.39.8

1935.7

12.2

2.4

10.312.2

74.8

4.9

0

25.6

Numbers in bold refer to the European level, while normal numbers refer to national levels.

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