Bridges

Co-ordinator:
Mcrit (Barcelona)

Partners:
ME&P (Cambridge), NTUA (Athens), DTU (Copenhagen), Mkmetric (Karlsruhe),
SOFRES (Paris), TRT (Milano).

 
   This page contains:

4.1 The Bridges Communication System and System Manager (CS)
4.2 Specialised "bridges" to transport models (GTF) and to GIS and Database managers (GTF_GIS)
4.3 Bridges Core Utilities (NIS): Bridging database structures attached to transport graphs
4.4 Bridges Expert System: Towards a Decision Support System (ES/DSS)
4.5 Bridges Data Sources Directory: The Bridges Digital Data Sources Guide (DDG)

The Bridges research project was developed within the European Community's 4th Framework Programme of research, between 1977-1999 within the "Strategic Transport" field. The output from Bridges is a set of software tools and data formats designed to provide necessary backing for a European Transport policy Information System (ETIS). It consists of a "software technology" to develop open multi-software systems integrating independent external applications, such as Database managers, GIS and, in particular, transport models. Bridges software tools are research outputs, 100% owned by the EC.

Bridges has mostly been programmed in Borland C++ 5.02, and includes some Visual Basic 5.0 routines for database management. Some modules use other programming languages, such as Amzi Prolog (the Expert System), or component software such as MapObjects (the GIS_GTF translator and the Expert System).

An open multi-software system developed using Bridges technology will have some or all the following capabilities, required in the support of transport policy information systems:

• Presentation
• Project definition
• Maps
• Database manager
• Graphs
• Analysis
• Modelling
• Thematic Maps
• Decision-making tools
• Printing
• Visual settings
• Help information
• Internet connection

Systems developed using Bridges technology can be customised to include all of these options. Any existing sub option can be substituted by a module more appropriate to the specific problem the user is dealing with. Bridges is a fully scalable technology, so it is easy to develop and include new options in the future. Bridges technology can work on a LAN. In this case, each user will have his own personal workspace and the first screen when entering into Bridges will require the declaration of a name and password and the selection of an available workspace.
Behind the utilities accessible through the user interface, there are a number of specialised Bridges modules for managing open systems:

• The Communication System Bridges/CS
• The Management System Bridges/SYS
•  The translators for transport databases Bridges/GTF/GIS
• The directory of European Data Sources Bridges/DDG

These utilities need to be enriched with specialised tools to develop modules able to provide for an "intelligent intermediation" between system's outputs and policy meaningful answers: This is the role of Bridges/DSS. This report is focused on the user level, the user access to Bridges main utilities, instead of the analysis of the utilities themselves.

Bridges set out to fulfil the most demanding software requirements of an ideal ETIS but Bridges technology can also be applied for building up effective support systems in transport related fields (e.g. spatial development or environmental assessment) at various geographic levels (local, regional, national). This is demonstrated by the already available experience of implementing Bridges technology (see the Dissemination and Exploitation Plan in Annex 2).

Bridges technology was designed as a set of highly interconnected tools: communication systems, data models and protocols, specialised transport routines, applications to build intelligent user interfaces, component software routines and stand alone applications etc. Each Bridges tool can work alone and none is indispensable, and optimum implementation will always be through integration with other tools and external applications. This approach is consistent with (and complementary to) current strategies adopted for management support systems and electronic business by leading software companies such as ORACLE and Software AG.
At the time of writing (late 1999), Bridges is a productive software technology which has been successfully applied to building of advanced support systems.

Systems developed using Bridges have the following advantages from the end-user point of view:

• They are scalable multi-software systems: supported by the Bridges Communication System, a Windows'NT/98 compatible technology, able to integrate multiple and specialised software applications, in particular sophisticated transport models, database managers and GIS.
•  They are open to the integration of any Windows OLE/COM compatible application and component software. Advanced transport models (usually non-interactive applications, often not OLE/COM compatible) can be integrated through a new common data model and format (Bridges GTF), as well as transport database structures managed by GIS applications (Bridges GTF_GIS)
• They are highly productive systems, with a set of Bridges Core Utilities specialised in transport database management (e.g. network oriented database and GIS routines to harmonise information linked to heterogeneous graph structures).

They are intelligent systems, able to facilitate intermediation between policy questions and outputs resulting from scientific models.

They are user friendly systems, with specific Bridges Core Utilities supplying the place of previously missing or sub-optimal data management and mapping tools needed to develop powerful user interfaces
From a system developer's point of view, Bridges technology has the following impacts:

• The time and cost of building up an advanced multi-software support system is dramatically reduced by Bridges Communication System (CS) (this explains why so many Bridges implementations have been possible even before completion of the research).

• Bridges Network Utilities (NIS) provide a number of independent modules, for instance new graph management tools (e.g. graph editing, matching, analysis etc.) which have already proved to be very efficient to develop precise and topologically rich graphs of Europe. This set of transport oriented database management tools is closely linked to transport modelling (including network assignment routines) and may be the starting point for building interactive models based on the formulation and results of more advanced external models.

• For the first time, Bridges data models and formats (GTF) provide a real possibility for transport modellers to exchange of databases. Currently, heterogeneous data models (even terminology) and individual formats make the data exchange process extremely costly, when it is feasible. This problem is blocking modelling research to some extent, since cross-fertilisation and interaction between models is very difficult (e.g. using the same database and comparison of results obtained with two different models is far from easy)

• Bridges data models and formats linking transport models and advanced (GTF_GIS), as well as the ArcInfo translator, allows use of GIS not only to display modelling results (as a mapping tool) but as a database management tool as well. These capabilities can become especially useful in a data warehouse approach.

• Bridges Directory of Transport Data Sources (DDG) demonstrates the actual feasibility of building simple and highly useful tools, with potential in the transport planning sector. DDG demonstrates the necessity of developing a set of electronic directories (for data sources, models, policy questions, experts and advisors etc.) in the ETIS context.

• Bridges Expert System (ES/DSS) is the first attempt to develop a methodology and, based on it, a software tool able to provide intelligent intermediation between advanced models and end users (decision makers). Complex tasks, such as writing model templates to interpret model results and translate user queries to model parameters, can be carried out relatively easily by system developers.

All considered, already existing experience proves that Bridges technology is an innovative software technology in the following senses:

• It brings new capabilities (e.g. new data models and formats to import data from advanced transport models, a new Communication System to drive many commercial applications without being dependent on any of them, new GIS utilities for network and transport database management etc.)

• It optimises and refines already existing software tools (e.g. mapping tools for transport networks, easier interfaces to key database management utilities, fully personalised interfaces etc.)

All Bridges deliverables have been developed according to the work plan and continuously tested as research prototypes by their developers . Beyond this "internal research testing", most modules have been tested as well by other users than Bridges developers; some modules were successfully implemented in European and local institutions, and few of them are even being used on a daily basis for carrying out a variety of activities. Even if none of these applications covers the whole ambition of Bridges (supporting a European Transport Policy Information System), together they provide a good testing and customising environment for specific Bridges modules .

Once the research was formally over in terms of development and internal testing, all succeeding Bridges applications involving testing exercises have been financed or co-financed by Bridges partners alone, independently from 4th Framework Programme. This customising and testing process (following real user demands), carried out after research, is consistent with the pre-commercial and pre-competitive character of the 4th Framework Programme.

On the other hand, during the process of developing Bridges, a large number of workshops and presentations (about 15) have been held in Brussels to disseminate and discuss preliminary results with EC/DGVII, EUROSTAT, EIB and other DG's. Other specific workshops with EEA and EC/DG REGIO have been held. All of these workshops were open to all interested people but were always targeted to selected audiences and included the installation of the software and the distribution of documentation to all the institutions mentioned.

As any other software technology, Bridges should be continuously updated and improved in order to provide effective software solutions to build up open multi-software systems to support transport policy-makers. Changes in the personal computer environment, as substantial as those that occurred during the nineties, are not expected to continue at the same rate in coming years. Windows NT is likely to remain the standard and major innovation will be linked to Internet technologies (e.g. electronic commerce). Together with testing, improving and updating the technology for Intranet, Internet "bridges" will remain the most interesting research topic for the future to remain at the forefront of technology.
Bridges research followed a highly interconnected and de-centralised development process, based on continuous feedback. As a result, all Bridges elements share fundamental concepts making them fully compatible with each other.

According to the "Value Stream" approach adopted, each Bridges Work package was led by one research partner who had to produce a specific deliverable defined to fulfil a precise user need, as illustrated in Figure 1. Bridges partners were urged by the coordinator to produce "throw away rapid prototypes" to provide a view of each partner's ideas and thoughts at an early stage of the research. Based on the analysis of these prototypes, and the spontaneous cross-fertilisation provided by the simultaneous viewing of all final deliverables, successive "evolutionary prototypes" were developed. This process allowed all partners to "begin with the end in mind", an essential requirement for highly innovative (so very risky) research projects.

Figure 1 Bridges Technology for building transport policy support systems
In more conventional "Stovepipe" management systems, work packages respond to the internal logic  the developer rather than that of the final user (consumer or client), and each one can be divided into different activities with many developers working with complex interrelations and input-output dependencies. While this management structure may be well suited to mature areas and mature partnerships (with little risk of failure at intermediate input-output steps), this is not the case for immature technologies (such as software development) and immature partnerships (based on heterogeneous multinational organisations) as in Bridges. For these cases the "value stream" approach adopted is much more suitable.
A Bridges brochure has been produced with a precise and synthetic description of the final research outcomes. This Final Report constitutes another step forward from that brochure in that it provides a clearer picture of what Bridges technology is because it includes the experience of partners developing real support systems using Bridges. Only the personal interaction with policy makers and experts, the practical observation of how much Bridges technology helps to solve their requirements in a productive manner, has helped the Bridges partners to communicate what Bridges technology is all about more efficiently.

Figure 1 Bridges Technology for building transport policy support systems

In order to understand the technology, the Bridges tools can be differentiated by the different levels of expertise needed for their use:

• Specialised transport routines and applications, not available or poorly implemented in the market place, which can be used by non-expert users (e.g. DDG, some NIS routines),
• Ready-to-use applications and formats to be used by expert users to link advanced transport models to pre-existing systems (e.g. ES/DSS, GTF Format)
• Other tools to enable multiple software modules to work together in an integrated system (e.g. Communication System). They also allow the organisation and management of a number of personal user workspaces within the overall system and distributed via a Local Area Network. These are tools for expert users and system managers.

The Bridges Communication System harnesses OLE/COM technology to integrate stand alone applications. The Bridges Communication System is based on managing flows of command messages between stand alone applications. Bridges Communication System was designed to work in an Intranet but its decentralised architecture allows the addition of a new bridge to the Internet.

The Bridges Intranet Communication System facilitates simultaneous on-line dialogue with commercial applications . Transport models, even those supported by the few available OLE/COM compatible modelling packages, pose additional problems for "bridging" such as when they are based on independent non-interactive modules or they use incompatible data models. This requires more specific tools for example common data formats, such as Bridges/GTF.

In addition, "bridges" which allow different applications to share the same database were developed. However, the simple import and export of databases is not the main problem to be solved: The main problem is to define a common data model and format protocol for the exchange of complex transport oriented databases, which can grow into a standard for transport modellers.

The Bridges System Manager helps to personalise an open systems architecture to the specific needs of each user connected to it. Because of the modular and scalable character of systems developed by Bridges technology, each user has their own "personal Work space", which may contain different applications and different databases. "Friendliness" is therefore achieved by customising the architecture of the system to the needs of each specific user and problem. The Bridges System Manager allows an unlimited number of users to access the system, each with multiple customised workspaces. The Bridges Manager takes care of user passwords, work space maintenance and confidentiality issues.
Finally, the Bridges Common Interface allows the development of fully personalised menus and options, even beyond the design constraints of Microsoft Windows.

The Bridges Communication System, Management and User interface utilities have been programmed in Borland C++. Looking ahead, major improvements could be achieved by achieving Bridges communication through the Internet. Needless to say, this achievement would be a major step, placing Bridges technology in the forefront of software innovation.

A GTF (Generalised Transportion - data Format) has been defined as a format to store and exchange any transport oriented database. Data exchange between transport models requires that models share a common data model. The GTF data model was defined to be sufficiently open to cover all strategic models at European scale. Bridges' aim is to propose GTF as standard format to be adopted by EC and international institutions.

The GTF data model is able to deal with the complex graph structures and topologies used by transport models (including demand, supply and specific modelling aspects). Following the IDEFIX approach to data modelling, the following entities were defined: node, link, interchange, route service, zone, main mode, persons/goods, carrier, modal stage, and flow/movement. The GTF data model includes the categorisation of relationships. In addition, the adopted GTF format description is public, compatible with international standards (UN/GESMES) and complementary to other database and GIS standard formats. It includes both topological information related to transport entities and the statistical data attached to them.

GTF has been tested with MKmetric VIA and MEAP MEPLAN modelling tools, and it has been extended to cover GIS in cooperation with the GTF_GIS work. A GTF Translator to and from VIA Model formats to GTF has been programmed, with a separate version in Java to allow Internet accessibility.

The GTF_GIS data model is based on adding transport topology to conventional GIS structures, according to the GTF definition (e.g. routes-route segments, stops. The format description is very intuitive with simple ASCII files.

GTF_GIS entities are compatible to GTF but can enrich public transport entities: links, nodes, turns, routes-route segments and segments, stops, changes, terminals, zones, fictive links, matrices-flows, vessels, units-persons/goods and milestones. Topological information related to entity relationships (e.g. allowed vessels and units on links, routes and flow matrices) is also included. Names of data tables containing statistical data and metadata information are listed within GTF_GIS but the actual data is not included.

Arc/Info, one of the most advanced GIS, is unable to handle the complex network topologies required for transport modelling (e.g. defining centroids' connectors, public transport routes and services etc.). Because of the high GIS productivity of Arc/Info tool, and its widespread use within European institutions, a specific "bridge" from Arc/Info's encrypted data format to GTF has been developed. The translator converts the Arc/Info GIS format into GTF_GIS by adding transport topology. A GTF_GIS-Arc/Info translator has been programmed based on MapObjects libraries, the only way to overcome the Arc/Info encrypted data format. The unavoidable use of such libraries makes the translator not totally royalties free.

Translators to standard CAD (DGN, DXF), GIS and Desktop mapping (MIF, SHP, GEO) formats have also been programmed. Given the limited GIS capabilities of these tools, they are unable to support advanced transport database structures. The interest of bridging these formats lies in the import of graphs developed on CAD, simple databases on GIS and the export of results to be displayed graphically. These translators have been programmed in Borland C++. Translators to DBS applications have been programmed based on ODBC drivers and Data Access Objects (DAO).

Bridges Core Utilities (Network Information System, NISystem utilities) have been developed as external stand alone applications to be linked to any system by the Bridges Communication System, just like any other stand alone application. This guarantees that systems developed by Bridges are fully scalable and independent even from Bridges own Core Utilities. Any Core utility can be removed and/or substituted by others when needed.

The paramount goal of NISystem Core Utilities is to complement transport modelling, GIS and DBS applications with missing utilities, particularly in the context of the ETIS reference requirements. NISystem provide:

• Specialised routines for harmonising heterogeneous transport oriented databases and graphs. Examples are "Graph matching" utilities to "bridge" databases attached to graphs with different link segmentations covering the same zone, "Graph checking" utilities to check topological properties on CAD files, "Graph editing" utilities to modify graphs and add topology to CAD files etc.).
• An original GIS binary format (MGS), based on GTF and GTF_GIS data models has been created to increase the productivity of CAD-GIS core utilities and also to overcome possible confidentiality concerns for data dissemination.
• Graphic management routines for CAD, Desktop mapping and GIS have been programmed and included in the system as "core utilities", mostly to support "bridges" which required more than simple data format exchange (e.g. the above-mentioned Graph matching). Moreover, core utilities facilitate maximum flexibility in customising user interfaces and also make Bridges technology not completely dependent on commercial applications but complementary to them.
• A complete database management application has been programmed in Visual Basic 5.0, allowing an optimum degree of user interaction with large and complex databases as well as enjoying several management utilities. Bridges database manager uses Microsoft MDB as default data format but is open to other formats through standard ODBC drivers and DAO.
• Operational research and statistical algorithms for analysing transport databases have been plugged into the system to provide Bridges users with specialised easy-to-access tools for checking, exploring and exploiting databases.

Core Utilities have been programmed in Borland C++ (CAD, GIS and Operational research algorithms) and Visual Basic 5.0 (Database management, EXCEL macro-language).

NISystem utilities have been encapsulated in a number of modules (e.g. the DATABASE module contains all Visual Basic DAO-based functions to manage databases, as well as Microsoft Graph; VIEW contains all C++ routines to provide GIS visualisation capabilities; GRAPH contains all C++ routines providing edition, quality control and analysis of transport networks as graphs etc.). Each NIS module is an executable file which enjoys its own user-interface. It can be activated in the user-interface of the system similarly to any stand-alone application, simply by placing a button linked to the execution of the module.

ES/DDS has been developed and integrated into Bridges' toolbox to provide a tool to build intelligent translators between end users questions and sophisticated transport model outputs. The Bridges Expert System helps users to establish legitimate queries to models and interpret the model results. The ES has been tested by building the expert translators to MKmetric VIA, MEAP MEPLAN, and with the Spata Airport environmental impact model. ES/DSS has been defined and programmed with a medium and long-term ambition: the more sophisticated and numerous are the models "bridged" to ETIS, the more useful the ES/DSS tool will become in providing the expert interface.

ES/DSS architecture is composed of a user-interface (Object Oriented Interface, OOI) and the Expert System (ES). The OOI comprises a set of menus, forms, dialogue boxes etc. which are either pre-set or generated at run-time to facilitate user dialogues. The design part of OOI guides the expert user though the standard options of calling up a DSS module (data dictionary, template parser, expert system etc.) or a utility (Visdata, DSSview etc.).

The main task of the Expert System (ES) is to analyse user queries, decompose them into queries to be passed on to other modules, and to combine results into a meaningful form for the user to understand. In doing so, the ES may apply default values, assumptions and rules to fill in any missing data required for running other modules. ES comprises a Template parser, a Query processor, an ES Shell and a Multicriteria evaluator.

ES/DSS has been programmed in MS Visual Basic 5.0, Visual C++ 5.0, Access 7.0, ESRI's MapObjects 1.2 and Amzi! Prolog 4.0, according to OLE/COM. DSS is an OLE container application, therefore easily "bridged" to the rest of the components of a multi-software system by using the Bridges Communication System.

DDG has being developed as a stand alone application which contains European data sources and database descriptions (based on ETIS definitions). DDG follows a similar approach to the "Directory of Transportation Data Sources" published each year by the US Department of Transportation (Bureau of Transport Statistics).

The rational for including DDG in Bridges Toolbox was the assumption that ETIS (as with any other support system) would be limited to a minimum core of data useful for most studies, with links to additional data source providers as needed. On the other hand it was important to develop a public directory of transport information sources in Europe in the framework of Bridges to demonstrate the value of such a tool in the frame of policy support systems.

Currently, DDG is a data sources directory which contains updated information related to the main European Data providers and Data products, as well as available transport models and software products. Initially, DDG was focused on information databases and sources available in electronic format (CD-ROM) and sources accessible throughout the Internet but it was subsequently enriched by including sources available in conventional paper-form. It was also extended to cover available models/modellers and the major software products/providers.
DDG contains

• 558 European database products, providing information such as availability, cost, periodicity, legal reference, data etc.,
• 732 European information providers with contact information and Website summaries,
• 85 modelling products with information based on previous studies undertaken by DGVII,
• 76 modelling providers with contact information,
• 71 software products and
• 74 software providers have also been included.

DDG has a user friendly interface to define queries and achieve customised answers, as well as to establish direct links to data sources through their Internet Websites. It also allows users to update the directory themselves; therefore, it includes a precise codification of fields and checks to validate any new information introduced. DDG has been programmed in MS Visual Basic 5.0, and information has been obtained from a variety of sources.

The medium-long term of ambition of Bridges technology is to be used for building up ETIS as an open multi-software policy support system. This implementation is now feasible because the three main components to be "bridged" are, to some extent, available:

• Databases
• Different type of models
• Policy studies

On the other hand, the experience of first building smaller support systems, using Bridges technology in the European transport policy field is demonstrating that Bridges can supply those specific software requirements of an advanced European transport policy system which were previously missing .

The aim of Bridges is to solve as far as possible the lack of compatibility and openness of advanced modelling tools and also between models and other software tools (e.g. those supporting database structures and facilitating interactive viewing of results). Instead of a new transport modelling tool including GIS and database management, the outcome of the Bridges research is a software technology (a "toolbox") "to bridge" models, GIS and database managers in productive and user friendly multi-software support systems. Therefore, Bridges' major goal was to enhance the productivity of information and modelling tools by "bridging" them, including the building of multi-software platforms.

By closing the "software gap" between transport models and other software tools, Bridges technology can help to reduce the more fundamental gap between advanced modelling tools and end users (e.g. experts, decision makers). Systems developed using Bridges tools can put advanced analytic tools in hands of people who are not software specialists; highly customised interfaces can be programmed to give users friendly interaction with advanced tools.

Bridges research is a Windows NT compatible technology, but its Communication System was designed to allow future Internet compatibility and some promising avenues towards such compatibility have already been explored. In particular, a Bridges Server, able to receive remote messages from Internet browsers and interact with Bridges Intranet Communication System is under development as a follow up to the research. The development of such a Server may require modification of some elements of the whole Bridges technology (e.g. the Communication System and NISystem), but the fundamental Intranet design concepts presented in this Final Report will remain as they are.

The Bridges research effort, by its very nature, could not reach a final, definitive conclusion. Each one of the systems mentioned requires the improvement of existing tools and even, in same cases, the development of new ones. For example, the "bridges" between transport models and Virtual Reality and 3-Dimensional applications, which were not part of the original Bridges research because their limited interest for European transport planning, are more important when developing support systems at urban scale. Other "bridges" with advanced modelling tools such as GAMS, TRIO, SPSS etc. will also be of greater interest and are expected to be developed as required by new applications). More importantly, many advanced Bridges technologies (e.g. GTF format for data exchange, and Expert System/DSS) have not yet been applied in real cases. It is expected that many of these more advanced technologies will be taken forward in further research activities.

Finally, the development of a "bridge" between Intranet multi-software systems build with Bridges and Internet is the area of most interest from a software development point of view. In the context of ASSEMBLING, another 4th Framework Programme project, which aims to develop a pilot Internet executive support system for European transport policy-makers, this is currently being explored. Once achieved, the integration of the results of both projects may provide for an optimum use of forefront software innovation to support a friendly access (both Internet and Intranet) to advanced transport information and modelling systems.
All things considered, each Bridges module requires a different further research strategy:

BRIDGES/DDG: Maintenance will consist of improvement to the directory of sources, extending the number of sources, updating existing ones and establishing a mechanism for automating the process in the future. From a software point of view, no major maintenance work is required. However, it will be especially important to migrate DDG from Windows to the Internet.

BRIDGES/Communication System: Being a software product, maintenance is linked to the implementation and use of the tool for specific users and purposes. A major improvement would be to make the system Internet compatible.

BRIDGES/NIS: The maintenance of NIS software follows the same lines as the BRIDGES/Communication System. An important improvement will be the further extension of the NIS' own interactive modelling capabilities.

BRIDGES/GTF: While no maintenance is required in relation to the actual format description, it will be important to open it to discussion by a wider range of modellers and end users. In relation to translators, once they demonstrated the feasibility of the GTF vision, no maintenance is required. They should be reprogrammed into Internet-compatible applications for more general use.

BRIDGES/DSS: The implementation of DSS would require incorporating a model's template, based on the specific needs of the transport model and end users. This is a complex task to be carried out by experts.

Bridges is a software technology for experts to develop open multi-software support systems, particularly in the field of strategic transport planning. As a "technology", Bridges includes a number of tools (a "toolbox" so to speak), methods and procedures for using them, and the overall scientific know-how and vision behind them. Resulting from the use of such a technology, several support systems have already being developed and are operational in hands of transport planners and decision-makers at European and local level (e.g. ICONgis for the European Investment Bank, BRAX, SIMU and SIET for different local planning administrations). Even if none of these applications cover the whole range of Bridges capabilities, in total, they demonstrate the usefulness of Bridges research outputs. Bridges was developed within the Strategic Transport element of the 4th Framework Programme, between 1997-1999. Bridges software tools are research outputs, 100% owned by the European Commission.

Bridges research was defined in the context of the ideal user requirements for a European Transport policy Information System (ETIS) and the problems and opportunities presented by already existing or expected software applications, data formats and transport strategic models needed to fulfil the user requirements of an ideal ETIS. The ETIS concept, and its various components, is also being developed as an element of the strategic tasks of the EC's Transport research programme.

In broad terms, user requirements for advanced systems such as ETIS can be summarised as "maximum capabilities with minimum complexity". Since there is no relevant experience of transport software support systems as demanding as ETIS, the starting point for Bridges research was the assumption that the best system architecture to meet the ETIS requirement was a multi-software architecture open to the integration of external advanced support tools ("maximum capabilities") and to be driven from fully personalised and user friendly interfaces ("minimum complexity"). Moreover, this kind of modular architecture is required because there is enough empirical evidence to show that the rapid evolution of Information and Communication Technologies means that only highly decentralised and strongly interconnected systems are flexible enough to be continuously adapted and improved. In the particular case of ETIS, this open system architecture becomes indispensable: new databases and more advanced models are expected to emerge in the next few years, mainly from the European research programmes, for the assessment of current and new policy questions using both main-stream and innovative scientific theories. ETIS users are likely to become more demanding as they gain experience. ETIS development will therefore be an endless "process" rather than a fixed "product", so that the software architecture supporting it must be flexible enough not to act as a block.

Needless to say, in this inclusive and dynamic system vision, the "bridges" making efficient connections among all system components and, subsequently, between these components and the different users, become crucial elements in making the ensemble behave as an integrated system under user control. Bridges is about designing, developing and testing efficient software solutions to build such software "bridges".

There are no commercial software tools supplying all the "bridges" needed for efficient transport-oriented open multi-software systems like those envisaged, and even the available Windows-compatible tools to link independent applications are sub optimal for many ETIS-related specific purposes. Therefore, Bridges research has developed an entirely new set of tools to fill the most important gaps.

Bridges technology has largely been programmed for a Windows NT environment in Borland C++ 5.02 but with some complementary Visual Basic 5.0 routines. Other programming languages are also used, such as Amzi Prolog (e.g. the Expert System), or component software such as MapObjects (e.g. the GIS_GTF translator, the Expert System) or Microsoft Graph (e.g. to carry on some graphic displays within NISystem).

The main Bridges technology components (the "bridges") are:

• Digital Data Guide (DDG): A directory of available information sources relevant for ETIS
• Generalised Transportion-data Format (GTF): A proposed standard data format for transport database exchange, aimed at the transport forecast and evaluation models area.
• GTF/Arcinfo Translator (GTF/GIS): An application for transferring data from Arcinfo GIS formats to a GIS version of GTF.
• Expert System/Decision Support System (ES/DSS): An application to define rules and criteria to simplify the interface between end users and complex transport models.
• NISystem (NIS): A set of routines able to handle advanced transport topologies and carry on graphs analysis.
• Communication System (CS): A technology to manage the transmission of commands between independent applications integrated into an open system by the use of multiple customised user interfaces (user work spaces) in an Intranet environment.

Many of these tools have already been successfully tested by developing operational systems, currently in use in a number of transport planning administrations at both local and European levels.

Many Bridges components are already being implemented by the Bridges partners, in collaboration with other companies and institutions. These experiences cover a variety of areas, from systems actually implemented in institutions and in use by their personnel (e.g. SIMU), systems in the process of being implemented (e.g. ICONgis -see www.mcrit.com/icongis-, BRAX, SIET etc.), acting as support to dissemination drives (Phare Toolbox) or educational initiatives (PIE), systems used in consultancy work by Bridges partners (PSCUT, SCANRAIL) or systems being developed within European research projects (e.g. Pyrenees, ATIS). Each one of these systems is different, uses different Bridges tools and commercial applications, and is at a different level of development. Despite the fact that not all Bridges tools have yet been used, especially the more advanced ones, all these support systems constitute excellent opportunities for testing and improving fundamental aspects of Bridges technology.

Even before the formal end of Bridges research, a number of real applications have been already implemented and work in hand of their users. For example the ICONgis/ EIB for the European Investment Bank to assess large transport infrastructure projects in Europe, and the SIMU/ IMU, Urban Information and Modelling System for the Institut Municipal d'Urbanisme of Barcelona, designed for environmental impact analysis at local level. These two policy support systems and several others under development helped to test software tools and validate the overall approach of Bridges. Even more important, they have been extremely useful helping Bridges technology to start the process of moving from the research laboratory to the of policy makers' and experts' personal computers.

In the context of technology oriented research such as Bridges it is always important to remember that a Policy Support System, or a more general Decision Support System (DSS), such as PJGIS or SIMU, is a software system under control of one or many decision makers that assists but does not replace them. Therefore, the development of a decision support system is about people, not about computers. Although computers and software play an integral role in the DSS world, the study of DSS is about how people think and make decisions. The definition and implementation of a DSS must integrate future users as much as possible, since for them a DSS represents both a challenge and an opportunity to improve their working processes. In any case, a DSS will induce organisational changes which cannot be successful unless they are clearly perceived and desired from the outset. Recent developments in the DSS field tend to integrate the multiple decisions being taken by the institution, so they become Organisational DSSs. A successful ODSS will be a participative rather than a mandatory process.

Because of these user and institutional requirements, only decentralised and highly interconnected modular technologies can support a DSS. Moreover, only modular technologies are flexible enough to be updated and improved according to rapidly and unexpectedly changing conditions for both information and technology.

One important implementation advantage of Bridges technology is that being 100% financed by EC it is royalties free for all EU institutions (and others with EC agreement), and therefore an unlimited number of users can be connected to systems developed on Bridges with no licensing fees. For large institutions this advantage is crucial at least in the short term to stimulate their interest to be involved in the development of their own support systems, a process which anyway would require a serious organisational effort. The following list exemplifies the on-going experience in building up friendly and open multi-software systems based on Bridges technology (in some cases including decision support capabilities, in other cases just modelling and/or information):

1. ICONgis in the European Investment Bank (Transport Infrastructure Assessment, May 1999-October 1999)
2. SIMU in the Urban Planning Department of the City of Barcelona (Environmental Impact, January 1998-October 1999)
3. Phare Toolbox for DG7/Phare Countries (Dissemination of data, formulation and results of traffic forecast models, July 1999- end planned November 1999)
4. BRAX in the Barcelona Regional Agency (Urban Development linked to Public Transport, starting October 1999- end first phase February 2000)
5. PSCUT for JAE Junta Autostradas de Portugal (Mapping/Strategic Modelling, January 1999-July 1999)
6. SIET for the Metropolitan Plan of Barcelona (GIS/Strategic Transport Modelling, February 1998- January 2000)
7. SCANRAIL-Denmark (GIS/Transport Modelling links through Bridges ArcInfo translator, July 1999)
8. ATIS (Alpine Policy Information System demonstrator) for DG7 as a pilot case-study for ETIS (December 1999)
9. Pyrenees Information System (for ASSEMBLING research, 4th EU FP, October 1999- July 2000)
10. PIE GIS/Mapping system for educational purposes (Educational Software Program, Catalonia). Free GIS/Mapping for 2,000 schools (500,000 students between 16-18 years).

These applications (for further information please visit www.mcrit.com) demonstrate the feasibility of using Bridges technology to build up advanced policy support systems in transport or other closely related policy fields, as well as their productivity.

A 10-color page brochure containing synthetic information of Bridges has been produced for free dissemination (1.000 copies). The key dissemination strategies to market Bridges were:

• Bridges: Just tools?
• Friendly and productive access to advanced tools
• Independent and highly interconnected tools
• Common Bridges: Communication tools for multi-software systems
• Bridging models: Generalised Transportion-data Format
• Bridging GIS: Translators to/from GIS formats
• Core NIS utilities to manage transport databases
• Bridging information systems: Digital Data Sources Guide
• Empowering policy-makers: Decision-Support System

In collaboration with the Local Council of Barcelona, 1,500 copies of a first CD-ROM containing SIMU (System for Urban Information and Modelling) have been pressed for distribution. The CD-ROM documentation has also been translated into Spanish and English to allow for diffusion beyond Catalonia. Other applications (Phare Toolbox) will be produced as CD-ROMs for dissemination and will include specific databases and models in addition to the Bridges software systems.

When a specific application for European databases is ready, the possibility of producing a CD-ROM version for free dissemination will be studied. However legal concerns, if GISCO and EUROSTAT data for example were to be included, would have to be solved in the meantime. A CD-ROM containing Bridges tools only, without being implemented for a particular case will have a very limited interest. For the small numbers of specialists involved in similar work, direct contacts with the relevant Bridges partners would be preferable. It was to facilitate such contacts that the e-mail addresses of key Bridges partners were provided in the brochure.

Dissemination Plan: Current Implementation Work and Applications

Phare Toolbox (NEA, MKmetric, IWW, INRETS)
ATIS: Trans Alpine Pilot System (MESUDEMO, GEOSYSTRANS, ASSEMBLING)

The possibility of "commercialising" Bridges technology is restricted. On the one hand the market for new technologies to develop advanced support systems in transport is still relatively small, while, on the other, it would require an additional effort in documenting and testing all components. Even more difficult, it would need the development of a whole range of support services (e.g. training of specialised developers, permanent help support, continuous maintenance of the technology for a range of hardware platforms). However, it is possible that some Bridges components (GIS utilities specialised in transport networks, DDG) could become marketable products. Other components (e.g. data models and formats) could become official standards. The key strategy in the dissemination plan for the next year will be to identify the relevant institutions and people to work with developing specific implementations of Bridges.

info@mcrit.com