Transport safety: Trends and challenges from a systems perspective

Safety Science Vol. 26, No. l/2, pp. 107-120, 1997 0 1997 Elsevier Science Ltd. All rights reserved

Printed in the Netherlands 0925-7535/97

$17.00

+

0.00

PII: SW257535@7MOO33-7

TRANSPORT SAFEN: TRENDS AND CHALLENGES FROM A SYSTEMS PERSPECTIVE ’ John A. Stoop * , Wil A.H. Thissen Faculty of Systems Engineering, Policy Analysis and Management, Delft University of Technology, PO Box 5015.2600 GA Delft, The Netherlands

Abstract-A broad-brush overview of developments in transport safety is given. This overview does not pretend to be complete, but indicates a number of trends in the development of transport systems, taking into account operational and technological, institutional, and policymaking perspectives. These trends and their possible impacts for transport safety are elaborated with specific reference to Dutch road safety. While some of the changes provide opportunities for improvement in transport safety, many of them may have adverse impacts. Indications of a reversing trend in safety add to the need for new approaches to cope with the safety issues raised. Such approaches should be pro-active and address both substantive and procedural aspects, taking into account all system levels. In conclusion, a number of challenges are identified, including the development of transport safety as a more integral notion related to a better understanding of the transport system as a whole, implementing this notion in primary processes, technological and policy developments, and improving the safety knowledge infrastructure. 0 1997 Elsevier Science Ltd.

1. Introduction Despite ongoing efforts to enhance transport safety, empirical evidence does not suggest significant progress during the last decade. Rather, serious accidents and incidents with catastrophic potential keep recurring in all modes of transportation. For example, during the past decade a number of oil tankers grounded in European waters and spilled their cargo on the coast. At least three roll-on roll-off ferries flooded and capsized with unprecedented loss of lives, while several chemical bulk carriers suffered serious problems very close to the coast of The Netherlands. The Dutch aviation community suffered hull losses in Skopje and Haro, while an El Al plane crashed into an apartment block near Schiphol Airport. The frequency of

* Corresponding

author.

’ This paper is an elaboration of a presentation given at the farewell symposium for Prof. J. de Kroes, Delft, December

1994.

107

108

J.A. Stoop and W.A.H. Thissen

serious air crashes in general seems to be on the way up, rather than further going down (Hillestad et al., 1993). The Dutch railroads were confronted with passenger train accidents with loss of lives on several occasions, while internationally several serious accidents occurred with railroad wagons carrying hazardous materials. While road safety seems to have improved according to some counts (e.g. the number of fatalities in The Netherlands decreased from 3250 in 1972 to about 1250 in 19931, underreporting of less serious accidents has increased (Harris, 1989; RVV, 1992; de Kroes, 1994). At the same time a steady flow of serious accidents on motor ways keeps occurring, such as overturning tank lorries, head-tail collisions in congested traffic and accidents with tourist coaches. Whereas society seems to have accepted a certain degree of transport-related risk, the more serious accidents still draw a lot of public attention. Content analysis of newspapers over two years has indicated that issues such as accident causes, liability and blame were discussed for a considerable period of time after such events, especially if official accident investigation reports were issued (Hillestad et al., 1993). Clearly, increase in transport intensity seems to be one of the main causes of continuing or even increasing - risks. But several other developments inside and outside the transportation system may have an impact on transportation safety as well. Therefore it is relevant to identify trends and emerging changes in the transport system, to assess their potential impact on transport safety, and to explore possible approaches to effectively counterbalance or prevent undesirable safety impacts.

2. Transport systems; trends and developments All over the world, transport systems are evolving due to a number of changes in transportation markets and traffic developments. Transport systems are evolving from providers of capacity for transportation needs through logistic services into value-added logistical systems (Wormmeester, 1995). Single-modal stations and ports have changed into multi-modal junctions and a limited number will eventually develop into inter-modal mega-hubs in international networks. The emphasis of innovations and competition in the transportation market is shifting from the physical infrastructure to the intellectual infrastructure with respect to traffic control and management systems, ED1 and telematics. Last but not least, new technologies enable the use of underground space and earth sheltered structures, underground tunnels for long distance transport and new propulsion technology such as linear induction motors. The increase in knowledge intensity in the transportation industry is reflected by the foundation of centres of competence, research funding, and chairs in universities. For example, in the Netherlands, a research school for Transport, Infrastructure and Logistics (TRAIL) was established between Erasmus University and Delft University of Technology (Evers et al., 19941, and several chairs have been established in the field of logistics and transport policy. The transportation industry is evolving in a similar way as other industries, e.g. aviation and the process industry, did before. Multinational corporations emerge as mega-carriers in aviation and shipping, challenging the control over the logistic chain of merchants and replacing it with the dominance of carrier-haulage. International exchange of goods and passengers is incorporated in coupled logistic organisations. Ports and stations are no longer considered as stand-alone sites, but as components of integrated networks and multi-modal

Transport safety

109

chains, which are in competition to meet the standards of international market leaders. In this context new integrated transportation systems are being developed. Technological changes are being implemented with respect to rapid-transit technology for cargo, IT and ED1 applications, inter-modal systems, high-speed trains and vessels. Managerial changes are developed in response to the increasing requirements of enhanced competition and growth in volume. As a result, much emphasis is given to, for example, slot optimisation, intensification of traffic flows and continuity and punctuality in regular services. Not only developments in the transportation industry itself have provoked change; changes in urban development and land use have contributed to changes in the transportation industry as well. Demographic changes in population, economic patterns, changes in communication and data exchange technology have introduced new patterns of communications and activities (Banister, 1995). These changes have expanded human activities beyond the boundaries of a regular %hour-day working schedule, an office, private company or governmental organisation. Increasing environmental concerns have raised questions about the use of natural resources and have put pressure on the transport system to reduce emissions to the environment. The increase in complexity and in variety of requirements has given rise to the need for new approaches in transport policy making and transport planning. Traditional, intuitive and experience-based approaches focusing on a single criterion such as road scheme optimisation, or demand satisfaction at minimum cost, must be replaced by more comprehensive analytic approaches explicitly taking systems complexity and conflicting objectives into account, and attempting to develop and operationalise concepts such as sustainable mobility (Miser and Quade, 1985, 1988; Thissen, 1992; Banister, 1994; Baggen, 1994; Miser, 1995). Finally, changes in the role of the state have induced changes in transportation systems (Banister, 1995). For a long period corporatism defined a dominant position for the national government, overruling conflicts between public and private partners, while the arbiter role of the ‘company state’ formulated conditions for the competition between private partners and guaranteed that there was public concern with safety and environmental matters. In many western countries, the concept of the ‘contract state’ has now gained favour. The market becomes the arbiter instead of the state, and cost control becomes central. In several countries this development has led to a policy of deregulation and privatisation in a number of sectors among which public utilities, communication and transportation systems. In The Netherlands air traffic control and maritime pilotage organisations, the aviation training schools and mainport facilities (e.g. Schiphol Airport) have been fully privatised, while the privatisation of railroad and public transport organisations is under way. At the same time the Dutch national government is decentralising by separating policy making from policy monitoring. A situation of ‘remote control’ is aimed for, in which strategic frameworks and targets for land use, transportation and environmental issues are defined at the national levels and operational responsibilities are delegated to regional and local levels (SVV-II, 1989; VINEX, 1988; QmR, 1989). Currently, the need for some form of governmental intervention is still acknowledged with respect to the need for regulatory, safety and environmental requirements. With respect to the construction of major infrastructure projects, congestion management or environmental policies the Dutch national government still claims the right to and need for new legal and procedural instruments to assess and implement their plans in a faster and more effective way (WRR, 1994).

110

J.A. Stoop and W.A.H. Thissen

3. Road safety policy on a national level; the Dutch case 3.1. Procedural aspects Road safety policy in The Netherlands is addressed along three relatively independent angles, each covering a specific aspect. First, road safety is embedded in the general transport policy plan called ‘Structuurschema Verkeer en Vervoer II’ (SVV-II, 1989). Here, emphasis is on design and implementation of what is called a ‘sustainably safe’ infrastructure, i.e. an infrastructure in which safety concerns have explicitly been taken into account in the design phase to make it ‘inherently’ safe. Second, safety in all modes of transportation is considered in the context of land use and environmental policy planning. Here, the third-party or external risks of transport of hazardous materials are central. Third, road safety is considered to be part of integral safety from a perspective of public order and security as that concerns local authorities, including disaster management and contingency planning (IVR, 1993). The SVV-II plan identifies three major policy goals: individual freedom, social amenity and accessibility. For road safety a policy target is set to reduce road accidents by 25% in 2010 compared to the 1985 level, coupled with rapid implementation of in-car micro-electronics and of traffic flow management systems on motor ways. Behavioural strategies towards individual drivers concentrate on improvement of safety awareness and education, particularly in relation to non-residential roads (up to 80 km/h). Planning and implementation is being concentrated at the level of regional areas. Decentralisation of policy is being effectuated by allocating responsibilities to local authorities, with co-ordination of the policy at a regional level by Regional Committees for Traffic Safety. The land use planning and environmental policy aims to realise a spatial concentration of activities and primary function allocation (VINEX, 1988). Transportation corridors have been defined within which (inter-)regional and supra-local traffic should be concentrated. At the same time the concept of compact cities was formulated. Safety issues are considered to be external risk aspects of the transportation of hazardous materials, which could be tackled by the application of quantitative risk analysis and risk zoning for individual and group risks (AVIV, 1991; Beroggi et al., 1993; RWS, 1994). This approach can be seen as an extrapolation of the risk analysis and management strategies as applied in the process and petrochemical industry. However, while in The Netherlands extensive procedures have been developed for environmental impact statements, including the establishment of a committee of independent experts who judge the statement, there is no such instrument or procedure available for a more integrated safety assessment of major infrastructure projects (Stoop, 1993; Cachet et al., 1994). Finally, road safety is considered to be one of the hazards encountered in the public order and security domain. As such it is the responsibility of the Ministry of Internal Affairs and of regional and local public authorities. Safety is seen as confronted with a fragmented understanding, insufficient enforcement, low public risk awareness, low governmental involvement in problem definition and a low political priority (IVR, 1993). The formulation of a new approach is in its early phases, but is moving to a more integral definition of the safety issue by the use of a safety chain concept, to greater coherence within governmental policy making and more co-operation between the various levels at which responsibilities are defined (RWS, 1995). This approach aims at a more prominent role for inter-departmental co-ordination in safety policy making, especially in the area of crisis management.

Transportsafer,

III

3.2. Substantive aspects

Initially, the safety issue within the SVV-II context was addressed in a conventional manner, based on statistical data analysis and a further elaboration of the traditional engineering-education-enforcement triangle of measures concentrated on the operator level. Raad safety policy focused on priorities such as drunk driving, in-car collision protection, speed, black-spots, heavy lorries and the safety of bicyclists and mopeds. This line of approach was a consequence of the evolution that had taken place in a number of decades, starting in the fifties with legislation and gradually shifting to construction of motor ways, passive safety devices, behavioural control strategies, followed by decentralisation of policy and ‘sustainable’ safety in the nineties (SWOV, 1990). After a period in which the targets for reduced numbers of road casualties seemed within reach, a setback was encountered in the early nineties. Gradually the decreasing trend in fatalities levelled off and the number of fatalities started to increase again. This reversed trend triggered a change in road safety policy with the introduction of the notion of sustainability and an emphasis on road safety as a public health problem (SWOV, 1990). The emphasis on the infrastructure component of road transport was fuelled by the notion that inherent saf&y can be achieved by road design rather than by behavioural, legislative or educational strategies. The concept of ‘sustainably safe infrastructure’ is based on a categorisation of roads and infrastructure elements into a small number of types each clearly linked to user rules and expectations. Additionally, a discussion has been going on for several years to draw benefit from the experiences with accident investigation in other modes of transportation by independent boards such as the National Transportation Safety Boards in the USA, Canada and Sweden (Goemans and Joosten, 1993; de Kroes and Stoop, 1993; Kahan et al., 1995). Recently, it was decided to establish a National Transportation Safety Board in the Netherlands as well, with primary tasks in the field of accident investigation, but working across several modes.

4. Threats to and concerns about transport

safety

4. I. Introduction

The impacts on safety of the changes and trends indicated above are not yet fully clear. However, the continuing stream of major accidents and the upward trend in the number of accidents, most prominent in road traffic and aviation, provide reasons for concern. Therefore, it is worthwhile to look more closely at a number of trends and changes in the system, Bnd identify possible or emerging threats to safety. We will do this from a broad systems perspective, i.e. we will not concentrate on individual components or elements of transport, but rather focus on overall changes in the transport system in interaction with its environment. In the following paragraphs, we will discuss, in a broad-brush fashion: - the transport providing system, including operational, technological and institutional aspects; - the transport safety policy system; * the knowledge infrastructure supporting transport safety policy and management.

112

J.A. Stoop and W.A.H. Thissen

4.2. Transport system trends revisited

As with transport developments in the past, most of the trends or developments mentioned in Sections 2 and 3 are not driven by safety concerns. Some of the developments indicated do, however, offer new opportunities for enhancing transport safety. But others may very well have adverse safety impacts. Such an influence is not clear beforehand and can only be established by intensive study of the structure and dynamics of the transport systems involved. We will now, in a general sense, discuss the potential impacts of seven major trends on transport safety. First, the most prominent trend is the increase in scale and intensity. Without improvement of the system’s inherent safety characteristics, the probability of accidents and the size of their impacts will most probably increase more than proportionally with transport intensity. The number of accidents will increase proportionally with the traffic volume if a constant accident frequency rate is maintained. The probability of accidents may increase because situations of near congestion in a dense traffic flow, known to be accident prone, will occur much more frequently (Glansdorp et al., 1994). The impacts of accidents increase with both the size of volumes per shipment (or number of passengers per train or plane), and the number of transport units that may be affected by an accident. Second, mainports and transportation corridors provide a new type of phenomenon from a safety point of view due to their compactness and tight coupling. Interactions among different modalities may lead to low-probability high-impact events, with consequences similar to those of accidents in the process and offshore industry and nuclear power plants. For example, an air plane crashing on a train station or motor way close to the airport may have much more dramatic consequences than the same plane crashing in a open area. Due to tight coupling of infrastructures in corridors, the developments within the transportation artery may interfere with each other in such an unforeseen and unwanted manner, that safety is endangered (Thissen, 1993; Stoop and Van der Heijden, 1994). Accidents in one mode (e.g. derailment of a train carrying a hazardous chemical) may lead to trouble - and additional accidents - on neighbouring other modes. They may even block the other modes, as a result of which rescue squads may not be able to reach the location of the accidents at all. A tightly coupled design without a strategy which mitigates foreseeable risks, makes a hub or transportation artery vulnerable. Third, tight couplings in logistic chains may lead to vulnerability in a variety of ways. Operational pressures will tend to dominate safety concerns. For example, drivers or forwarders who see themselves behind planned schedule will be inclined to give highest priority to catching up with the desired time schedule, often at the expense of safety margins. Such operators should fulfil their tasks within the boundaries of the safe operating envelope defined for their vehicles, vessels and aircraft. Safety margins are threatened when exceptional weather conditions occur or under conditions of saturated traffic flows in restricted fairways. Analyses of recent accidents such as the Herald of Free Enterprise (van Poortvliet et al., 1994) or more general studies on the consequences of block-schedules in commercial aviation (Hillestad et al., 1993) emphasise this point of increased logistic interaction. Fourth, increased interdependence and an increase in the number of independent parties contributing to the overall system safety level make it more difficult to maintain safety standards in the system. If the organisation is not appropriate, an accident may escalate and reach a catastrophic level (van Duin, 1992). If no one body is responsible for the impact of the way in which interactions in the system are structured, each party will primarily look to its

Transport safety

113

own concerns in fulfilling its primary functions and overall safety may decrease. To combat this, new organisational forms for safety management are being developed and implemented, such as an Integrated Safety Management System at Schiphol airport on a mainport-wide basis, including all actors (Hillestad et al., 1993). Especially in emergency and contingency situations interdependence may hamper safety operations due to a lack of co-ordination and synchronisation between autonomous actors. Often, an accident site is not easily accessible during the first chaotic phase and specific local and regional conditions may aggravate the situation and extend the instability of the situation over long periods. Fifh, the emerging new technologies may have new sorts of impacts on safety. Expertise is being developed within numerous international research projects where market- and application-driven considerations are dominant (Prometheus, Brite Euram, DRIVE, EURET). Much is expected from the application of information and communication technology to enhance the effectiveness and reliability - and hence safety - levels of such technologically complex systems. System modifications typically concentrate on automation of subfunctions and subtasks, to reduce the workload of routine performance and to increase the efficiency and capacity of the system. Decision support of individual operators may be implemented in the work place, e.g. by the introduction of traffic flow management support at shore-based stations for harbour pilots. As indicated above, safety is not usually the prime objective of these changes in the system. As a result, economic criteria rather than safety criteria tend to dominate system designs. Improvements in safety may occur as a result of operator support and other sorts of management support (e.g. early warning systems for congestion and other traffic management systems, emergency management support, etc.). But, because safety is not a prime concern, new types of conditions contributing to unsafety may also result. For example, failures in automatic control devices and intelligent highway systems might lead to serious accidents, because drivers will not be prepared or able to react rapidly enough to unexpected events, and because the impacts of uncontrolled events may be very serious in situations of high speed and low distance between vehicles. Additionally, rapid and widespread introduction of new technologies must take account of their own learning curve during their implementation periods. New technologies may suffer from teething troubles in a technical sense. For example, the introduction of information technology and micro-electronics has resulted in accidents due to electro-magnetic interference. Recently an European Directive on Electra-Magnetic Compatibility has had to be issued to deal with this problem. Sixth, privatisation affects the way in which safety policy making and safety policy implementation take place. It is not clear yet to what extent a national government may still be capable of a pro-active policy if resources and authority have been delegated to private organisations. Parallel to privatisation, decentralisation of responsibilities to a lower level in governmental organisations is aimed for. This may have adverse safety effects if a subsequent monitoring and evaluation at a national level is not provided for. The extent of these impacts is not fully understood yet, and solutions to prevent or neutralise possible undesired effects have not been developed. For example, new divisions of responsibilities raise questions about the lack of priority given to safety data collection by the authorities, causing a serious underreporting of accident data, such as in the area of less serious car accidents, bicyclists and pedestrians (RVV, 19921.

114

J.A. Stoop and W.A.H. Thissen

Another problem may be that certification procedures and notifying bodies typically lack a short-term capability to respond quickly to technological or institutional change. They rely on feedback from the field as a signal for change and on the slow process of reaching international consensus as the basis for their decision making and recommendations. If response capabilities are not fast enough, a more pro-active approach is needed, requiring improved capacity to foresee safety problems. Seventh, additional emphasis is being put on the external safety of inhabitants and of other activities. Enforcement of zoning requirements with regard to allowable noise levels, of maximum risk contours for harmful effects of dangerous substances and of allowable risk levels for disasters also constrains the use of transportation arteries. This may lead to a complex stress situation between internal and external safety. For example, vessels transporting hazardous goods over the North Sea were re-routed further away from the coast to prevent spills and stranding. Obeying this re-routing procedure, they have to cross busy shipping lanes several times, causing increased collision risks to other vessels. Compliance with noise and environmental restrictions to flight procedures around airports located in the direct vicinity of residential area’s may require a steep climb with low engine power settings in a curved departure, which may be at the expense of the margins for a safe flight to avoid the risk of crashes. 4.3. Safety policy management

weaknesses

Policy making in the traffic and transportation area in The Netherlands is based on preventive action and shared responsibility of a variety of public authorities. However, experiences in the last decade have proven how difficult it is to translate general policy intentions into results. There is often no clearly visible benefit or gain in the short term in co-operation between departments which therefore focus on fine-tuning their traditional focus on partial goals. For example, the ministry of transport concentrates on the provision of ‘safe’ infrastructure and traffic management to accommodate transport demand, the ministry of economic affairs concentrates on maximisation of economic benefits, and the ministry of the environment on reduction of environmental impacts and external risks. In addition, responsibility for control of certain regulations, e.g. through the police force, rests with the ministries of justice and internal affairs, while the ministry of social affairs is concerned with safety at the workplace. A more integrated safety policy requires a jointly developed and supported policy framework outlining a desired balance between accommodation of transportation demands, economic benefits, environmental protection and conservation of resources, living conditions near transport links and hubs, and safety in its diverse dimensions (RVW, 1995). The traditional approach of the last five decades has been fragmented and evolutionary and the point of diminishing returns could have been reached. Yet, road traffic safety is not a matter of general public concern compared to crime or other issues; hence, except for incidental measures after major accidents, there is little support for putting road safety high on the political agenda. In addition, the responsibilities of national governments are being reduced and transferred on the one hand to the European level, e.g. in the certification and licensing procedures for vehicles. On the other hand local authorities are being made responsible for the implementation of national road safety policy and this co-ordination is being transferred to a regional level, leaving the national level with process management responsibilities but without substan-

115

Transport safe@

tive feedback. On the national level the role of the Minister of Transport as the co-ordinating minister for road safety has not been very powerful over the last decades. The awareness of safety as a policy issue may be reduced further by the current concentration of each Ministry and department on its own core activities. At a local level, road safety issues will be less visible due to the ‘dilution’ effects of small accident numbers in each local community. Local priority settings may not be in the road traffic safety area due to the autonomy of local authorities and regional police forces, especially if funding of safety enhancement strategies should be further reduced. Because of these changes, the national government no longer seems to be the primary problem-owner. There is little driving force to monitor safety targets, to bring uniformity into local policies and to take the final responsibilities at a national level. 4.4. Knowledge

and knowledge infrastructure

Existing theories and research findings may provide answers to some of the concerns about transport safety. Therefore, we first will briefly discuss two recent theories, focusing on the overall characteristics of complex systems rather than on individual elements or causes of risk. In his ‘normal accident’ theory, Perrow has identified a number of system characteristics which contribute to the safety performance of complex technological systems (Perrow, 1984). This theory analyses the architecture of systems, applying notions such as ‘complexity’ and ‘coupling’. Essentially, the theory states that as systems become more complex and coupled, unpredictable or ‘normal’ accidents become inevitable. Learning from accidents may take place, but system complexity may be so great that the failure path of one accident tells little about the failure part of the next one. Another recent theory about the prevention and management of accidents in complex organisations is referred to as ‘High Reliability Organisation’ theory (LaPorte and Consilini, 1991; Roberts, 1993). According to this theory safety in complex systems may be controllable if a number of characteristics are present: operational knowledge of the system characteristics, redundancy and transparency concerning the probability of error, learning capacity by organisational feedback, decentralisation of responsibilities, and top-management commitment to safety objectives. In fact, the two theories provide a view of different sides of the same coin: while increased system complexity introduces the possibility of new and unforeseeable accidents, compensation for this may, to a certain but unknown extent, be found in system redesign, improved feedback and learning processes, and commitment to safety. Which of the two views best describes reality is not clear yet; much depends on the specific system structure, safety culture and learning attitude. In a recent case study, for example, it was concluded that, for US missile warning and defense systems, Perrow’s ‘normal accident’ theory may provide a better description of reality than ‘High Reliability Organisation’ theory (Sagan, 1993). For the transport system, no such research has been performed yet. Transport systems have evolved into complex and closely coupled systems in which, according to Perrow’s ‘normal accident’ theory, accidents are bound to happen. However, according to the ‘High Reliability Organisation’ theory, safety management in such systems may improve if several conditions can be met. But road traffic systems do not fulfil these requirements; a good understanding of system complexity is lacking because of the use of simplified and highly aggregated models in systems and accident analysis (Thissen, 1991; Evers et al., 1994; van Poortvliet et al., 1994).

116

J.A. Stoop and W.A.H. Thissen

Statistical correlations in the analysis of highly aggregated accident data may be mistaken for causal relations. Biases in information collection, such as pre-occupation with the pursuit of blame, liability and disciplinary aspects, underreporting, and aggregation of data for policy monitoring objectives, may lead to misinterpretation in the search of causality (Asmussen, 1978). In-depth accident investigation is hardly applied in road traffic safety analyses, although it has proven its value in aviation, shipping, railroads, petrochemical and process industry, nuclear power plants and offshore industry (Stoop and Quist, 1986; Oude Egberink, 1987; RVV, 1991; Stoop and de Roes, 1991; de Kroes and Stoop, 1993; RVV, 1994; SOR, 1994). At a more strategic level statistical data and their processing through Quantitative Risk Analysis methods (QRA) do not provide a fully satisfactory answer to policy-related decision making (van Ravenzwaaij, 1994). QRA assumes that decision making on risk is based on a frequentistic risk perception as applied by decision-making actors, but actors who are actually exposed to the risks have been shown to base their risk judgement on a scenario perception and on what they see as most credible accident descriptions (Hendrickx, 1991). Moreover, QRA has its limitations in foreseeing risks of future use of new technology because it is based on historical data and experiences with matured technologies which do not take into account the effects of technological innovation and conceptual change in the system. More in general, adequate empirical analysis and knowledge development is hampered by the lack of an adequate knowledge infrastructure for transport safety research. At present, structural relations between accident investigation and scientific research only exist in special areas of expertise such as human behaviour, fatigue or navigation systems limited to single modes of transportation such as aviation and shipping. There are no centres of competence for the transportation industry which consider transport safety as a focal point of attention and look across modes and across disciplines. Safety research focuses on national policy advice or international projects on implementing technology (Fourth Framework, 1994). In The Netherlands there is relatively little effort on generic or fundamental research and within universities no professorial chairs or research centres focus on transportation safety in general. 5. Response directions and challenges In the preceding discussions a number of concerns have been identified with respect to the development of transport safety. Many of the possible impacts of current and foreseeable changes in the system have a somewhat speculative character. From a scientific point of view, they may be considered as hypotheses still to be proven or rejected on the basis of further empirical evidence. However, a policy strategy that would delay preventive action until undesired effects have shown up to their full extent in reality may not be considered a ‘safe’ strategy. The various concerns are serious enough to merit close attention from all parties involved, in particular from the research and the policy-making community. While no adequate responses to all the threats identified exist yet, a number of main lines of action may be distinguished. First, a shift in attention to a more integrated approach to the notion of ‘safety’ itself is needed. Internal and external safety, labour safety and quality management are related issues. Safety could be approached in a more integrated way, eliminating the traditional boundaries between the various safety aspects such as working conditions, hazardous materials transport, internal road traffic safety, urban planning and disaster and contingency planning.

Transport

117

safety

Second, in view of the slow learning and adaptation capabilities of transport systems and the related policy-making systems, a more pro-active approach is called for. In addition to focussing on likely events, more attention should be paid to thinkable or possible chains of events, in all phases of system design and operation. The discussion in Section 4 on new risks involved in closely coupled transportation corridors and mainports provides an example. Third, organisational solutions should be explored, explicitly defining and allocating joint responsibilities for monitoring, co-ordination and policy making in the safety field. Fragmentation of responsibilities and the lack of responsible problem-owners, in both the private and the public sectors, may be compensated that way. Fourth, approaches should be developed to improved balancing of safety concerns with other objectives, at different stages and levels of system and policy design. Instead of being a side-issue to be taken care of after primary objectives have met, safety should be dealt with in parallel with the primary functions of transport systems and organisations. This will require the development of integrated procedures and methods for safety impact assessment. Analogous to the development of environmental impact statement legislation and methodologies, procedures and methods for safety impact assessment may be developed, which, at longer term, may become part of integrated assessments to support policy and decision making. The availability of such methods would enable explicit trade-offs among safety and other objectives, and may contribute to political and management support for safety concerns. Fifth, the transport safety research community should provide the necessary insights and knowledge to realise some of these changes. Based on the preceding discussion, the following challenges may be identified: * The development of conceptual, and, if possible, quantitative frameworks to describe system complexity in terms of multi-causality and multi-level structures. * The development of quantitative systems safety performance indicators for specific contexts and applications, to provide a basis for safety impact assessments. - Broadening and deepening of individual accident investigations to empirically support the broader, more generic research needed. Event-oriented case studies should more expliaitly attempt to learn about system complexity, from an interdisciplinary perspective. Such synthesis may both provide an improved knowledge base for transport safety policy making and give directions for research agenda-setting. - Redesigning the transport safety research infrastructure to change it from a fragmented, partial structure to a structure which will foster more coherent, interdisciplinary knowledge acquisition and diffusion. This will require co-operation between public and private institutions such as systems designers, component manufacturers, consultants, and academic research institutes, and between researchers with different disciplinary backgrounds.

6. Concluding

remarks

A number of changes and trends in the transport and policy systems and their possible consequences have been described. Although several developments are indicated it is not yet clear which of these trends will be dominant. The changes in safety perception and accident occurrence seem to indicate structural changes, not just incidental or stochastic divergence’s A broad-brush analysis of trends and threats to transport safety indicates a need for more pro-active and integral decision-making characteristics. Safety should be integrated in the

118

J.A. Stoop and W.A.H. Thimen

primary processes of transport systems and policy design, balanced more evenly against other systems goals and aspects. Accident and incident analysis should be broadened and deepened to take system complexity into account and support more generic theory building.

Acknowledgements

The authors thank the editor for many useful suggestions with respect to an earlier draft of this paper.

References Asmussen, E. (1978) Systeemonveiligheid; inventarisatie van de toestand (System unsafety, inventory of the state of the art). (University Teaching and Research in Safety, Final Report Symposium 11 and 12 October 19781.: Delft University of Technology, Delft. AVIV (1991) Risico-analyse hoofdvaarwegen. Risico’s van het vervoer van brandbare en giftige stoffen in binnenvaarttankers door Nederland (Risk analysis main waterways. Risks of the transport of flammable and toxic materials in inland shipping tankers through the Netherlands). Research and Advisory Body of engineers AVIV, Enschede. Baggen, J. (1994) Duurzame mobiliteit. Duurzame ontwikkeling en de voorzieningenstructuur van het personenvervoer in de Randstad (Sustainable mobility. Sustainable development and the facility structure of passenger transport in the Randstad). Thesis. Publishers Tinbergen Institute Research Series: 74, Amsterdam. Banister, D. (1994) Transport Planning in the UK, USA and Europe. E&IN Spon. Chapman & Hall, London. Beroggi, G.E.G. et al. (1993) Risikobewertung in den Niederlanden (Risk assessment in the Netherlands). (Study by order of the Academy of Technology Assessment in Baden-Wurttemberg. Project 12/93).: Faculty of Systems Engineering, Policy Analysis and Management, Delft University of Technology, Delft. Cachet, A. et al. (1994) Naar een haalbare Veiligheids-effectrapportage. Een studie naar de haalbaarheid van een besluitvormingsondersteunend instrument ten behoeve van het Integrale veiligheidsbeleid (Aiming at a realistic Safety Impact Assessment. A study regarding the realisation of a supporting instrument for integral safety policy). Department of Public Administration, Erasmus University, Rotterdam. Duin, M.J. van (1992) Van rampen leren. Een vergelijkend onderzoek naar de lessen uit spoorwegongevallen, hotelbranden en industriele ongelukken (Learning from disasters. A comparative investigation into the lessons from railway accidents, hotel fires and industrial accidents). Doctoral dissertation. Leiden University. Hague Printing and Publishing Company. Evers, J.J. et al. (1994) Transport, infrastructuur en logisitiek: een proeve van een integrerend onderzoeksprogramma (Transport, infrastructure and logistics: towards an integrated research programme). TRAIL Research School, Delft University of Technology, Delft, February 1994. Fourth Framework (1994) Transport, workprogramme and information package. European Commission Brussels. Glansdorp, C., Goossens, L. and Leurink, R. (1994) Operational benefits: Risk reduction analysis with Accident Sequence Precursor Methodology. (EURET-1.3/task 24a).: Marine Analytics B.V. and Delft University of Technology, November 1994. Goemans, T. and Joosten, J.G.J. (1993) Goede raad is niet duur. Een evaluerend onderzoek naar het functioneren van de Raad voor de Verkeersveiligheid en de Spoorwegongevallenraad in het licht van de toekomstige ontwikkelingen op het gebied van de transportveiligheid (An evaluating investigation into the functioning of the Dutch Road Safety Council and the Dutch Railway Accident Investigation Board in the light of future developments in the field of transport safety). KPMG Kleynveld Management Consultants, The Hague. Harris, S. (1989) Verkeersgewonden geteld en gemeten (Road casualties measured and counted). Institute for Road Safety Research (SWOV), Leidschendam. Hillestad, R. et al. (1993) Airport growth and safety. A study of the external risks of Schiphol Airport and possible safety-enhancement measures. European-American Center for Policy Analysis/RAND Corporation, Santa Monica, USA. Hendrickx, L. (1991) How versus how often. The role of scenario information and frequency information in risk

Transport

safer?,

119

judgement and risk decision making. Doctoral Thesis. Rijksuniversiteit Groningen. Van Denderen, Groningen. IVR (1993) Integrale Veiligheids Rapportage (Integrated Safe@ Assessment). Ministry of the Interior, Ministry of Justice, Ministry of Social Affairs and Employment, Ministry of Transport, Public Works and Water Management, Ministry of Housing, Spatial Planning and Environment, The Hague. Kahan, J.P., Stoop, J.A., Van Dorp, L., Frinking, E., Van der Horst, E. and Malone, K. (1995) An inventory of transport safety information in The Netherlands. European-American Center for Policy Analysis/RAND and Faculty of Systems Engineering, Policy Analysis and Management. Delft University of Technology, Delft. de Kroes, J.L. and Stoop, J.A. (1993) First World Congress on Safety of Transportation, 26-27 nouember 1992. Delft University of Technology, Delft University Press, Delft. de Kroes, J.L. (1994) Slachtoffers (Road casualties). Valedictory address. Delft University of Technology. Miser, H.J. and Quade, ES., eds (1985) Handbook of Systems Analysis: Ooerriew of Uses, Procedures, Applications and Practice. Wiley, Chichester. Miser, H.J. and Quade, E.S., eds (1988) Handbook of Systems Analysis: Craft Issues and Procedural Choices. Wiley, Chichester. Miser, H.J., ed. (1995) Handbook of Systems Analysis: Cases. Wiley, Chichester. LaPorte, T. and Consilini, P. (1991) Working in practice but not in theory: theoretical challenges of ‘High Reliability Organizations’. Journal of Public Administration Research and Theory l(l), 19-47. OmR (1989) Omgaan met risico’s. Nationaal milieubeleidsplan. De risicobenadering in het milieubeleid (Dealing with risks. National environmental policy plan: The risk approach in the environmental policy). Ministry of Housing, Spatial Planning and Environment. Dutch Parliament, assembly year 1988-1989, 21 137, number 5. Oude Egberink, H.J.H. (1987) Diepgaand onderzoek van verkeersongevallen (In-depth investigation into road accidents). (Report of the DOVO analysis team).: Safety Science Group, Delft University of Technology, Delft. Perrow, C. (1984) Normal Accidents. Basic Books, New York. Poortvliet, A. van et al. (1994) Risk Management of Complex Technological Systems: Towards a Socio-engineering Approach. Proceedings of rhe international Emergency Management and Engineering Conference, April 18-21 1994. Hollywood Beach, FL. Ravenzwaaij, A. van (1994) Risico-informatie in het veiligheidsbeleid. Een analyse van de bruikbaarheid van kwantitatieve risico-informatie in het Nederlandse exteme veiligheidsbeleid (Risk information in safety policy. An analysis of the usefulness of quantitative risk information in the Dutch external safety policy). Doctoral Thesis, Utrecht University. Roberts, K.H., ed. (1993) New Challenges to Understanding OrganisaGons. MacMillan, New York.. RVV (1991) ‘Ongevallen en oorzaken’. Advies inzake de opzet van diepgaand onderzoek naar de oorzaken van verkeersongevallen (‘Accidents and causes’. Advice concerning the set-up of in-depth investigations into the causes of road accidents). RVV (1992) De cijfers (ver)tellen. Advies inzake de registratie van verkeersongevallen (Figures tell. Advice concerning the registration of road accidents). The Dutch Road Safety Council, April 1992, The Hague. RVV (1994) Jaarverslag, periode 1991-1993 (Annual report, period 1991-1993). The Dutch Road Safety Council, March 1994, The Hague. RVW (1995) Verkeer en Waterstaat op weg naar een duurzame ontwikkeling (The Ministry of Transport, Ptiblic Works and Water Management on the move towards a sustainable development). The Council for Transport, Public Works and Water Management, The Hague. RWS (1994) Veiligheid vervoer over de weg. VEVOWEG Projectplan augustus 1994 (Safety of transport by road. Project plan August 1994). Ministry of Transport, Public Works and Water Management. Directorate General for Public Works and Water Management, Construction Dept. RWS (1995) 4sprong. ‘Het dilemma: De kwaliteit van de keuze’. Een blocmlezing van strategische aanknopingspunten voor (nieuw) verkeersveiligheidsbeleid (Crossroad(s). ‘The dilemma: The quality of choice’. An anthology of strategic connecting points for a (new) policy as to road safety). Directorate General for Public Works and Water Management. Central Dept. of Public Works and Water Management. Road Safety Dept. Sagan, S.D. (1993) The Limits of Safety: Organisations, Accidents, and Nuclear Weapons. Princeton University Press, Princeton/Chichester. SOR (1994) Spoorwegongevallenraad. Verslag periode 1 januari 1992-30 juni 1994 (The Dutch Railway Accident Investigation Board. Report period 1 January 1992-30 June 1994). The Dutch Railway Accident Investigation Board, October 1994, The Hague. Stoop, J.A. and Quist, B. (1986) Diepgaand onderzoek van verkeers ongevallen (In-depth investigation into road accidents). Safety Science Group, Delft University of Technology, Delft. Stoop. J.A. and De Kroes, J.L., eds (1991) Toekomstig transport, veiligheid voorzien? (Future transport. safety (to be)

120

LA. Stoop and W.A.H. Thissen

foreseen?). (Symposium report 21 May 19911.: Safety Science Group, Delft University of Technology, Delft. Stoop, J.A. (1993) Veiligheids effect rapportage. Contouren van een beleidsinstmment. (Safety impact assessment. Contours of a policy instrument). (Report to the Dutch Road Safety Council and the Dutch Railway Accident Investigation Board).: Faculty of Systems Engineering, Policy Analysis and Management, Delft University of Technology, Delft. Stoop, J.A. and Van der Heijden, R.E.C.M. (1994) Transportsystemen, Ruimtelijke Ontwikkeling en Veiligheid: hoe V.E.R.der? (Transport systems, Spatial Development and Safety: how to continue?). In ‘Planologische Discussiebijdragen 1994: part 2. Stichting Planologische Diskussiedagen/Delftse Uitgevers Maatschappij, Delft. SVV-II (1989) Tweede structuurschema verkeer en vervoer (Second transport policy plan). Dutch Parliament, Assembly year 1988-1989. 20922, numbers l-2. SWOV (1990) Naar een duurzaam veilig wegverkeer. Nationale verkeersveiligheidsverkenning voor de jaren 1990/2010 (Aiming at a sustainably safe road traffic. National road safety forecast for the years 1990/2010). Institute for Road Safety Research (SWOV), Leidschendam. Thissen, W.A.H. (1991) Systeembenadering en transport(veiligheid1 (System approach and transport (safety)). In Toekomstig transpott, veiligheid voorzien? (Future transport, safety (to be) foreseen?), eds J.A. Stoop and J.L. De Kroes. (Symposium report 21 May 19911.: Safety Science Group, Delft University of Technology, Delft. Thissen, W.A.H. (1992) Infrastructure and transport: challenges for systems engineering. In Proceedings 1992 2EE.E International Conference on Systems, Man and Cybernetics, Chicago, pp. 1452-1457. IEEE publication 92CH3167-5, Pisactaway, NJ. Thissen, W.A.H. (1993) Veiligheid van grootschalige infrastructuren (Safety of large-scale infrastructures). (Congress report ‘Betuwe Route’, 15 october 19931.: The Dutch Institute for Spatial Planning and Housing (NIROV) and the Associaton National Consultation Betuwe Route @LOB). VINEX (1988) Vierde Nota over de ruimtelijke ordening. Gp weg naar 2015 (Fourth Note on Land Use Planning. Heading for 2015). Dutch Parliament, assembly year 1987-1988, 20490, numbers l-2. Wormmeester, G. (1995) Hoge ambitie, lage abstractie; de factor kennis in transport en logistiek (Great ambitions, low abstraction; the knowledge factor in transport and logistics). Annual congress 1995. Knowledge for freight. Transport Technology Centre (CTT), 23 November 1995, Noordwijkerhout. WRR (1994) Grote projecten in Nederland; een analyse van het tijdsbeslag van twintig besluitvormingsprocessen (Large projects in the Netherlands; an analysis of the time needed for twenty decision-making processes). The Netherlands Scientific Council for Government Policy (WRR), The Hague, June 1994.