The problem

80 % of Europeans live in cities facing increasing problems of traffic pollution and congestion. This is also reflected in environmental, health and social problems, which also increase the economic burden of citizens. PROPOLIS aims at definition of long term urban strategies that can simultaneously improve the environmental, social and economic components of urban sustainability.

According to the replies to a questionnaire sent by the European Environment Agency to the EU cities with a population of more than half a million, major concerns for the quality of the urban environment in Europe are air pollution, noise and traffic congestion. Increasing road traffic was identified as the most important source for these problems. Recent studies have shown that almost forty million Europeans are annually exposed to at least one exceedance of air quality guidelines. For noise, about 450 million people, or 65% of the population in Europe, live in areas where the 24-hour equivalent sound level exceeds 55 dB(A), and almost 10 million in areas where it exceeds 75 dB(A). The problem is also reflected in the 40.000 yearly fatalities in traffic, the 2% loss in GNP due to congestion and in the continuing growth of traffic. PROPOLIS addresses these and other global, regional and local problems, such as greenhouse gas emissions, energy use, urban economy, environmental and social issues.

  

State of the art

Policies, including transport, land use, regulatory, investment, fiscal and pricing policies, have been planned and partly implemented to improve the situation. Results show that these policies have not been able to stop the decrease of sustainability of our cities. Even to maintain the existing sustainability level will require the adaptation of radical policy measures. This will not be possible if the effects of these policies cannot be clearly demonstrated including also the distribution of the effects between different socio-economic and other groups. It has also been shown that many of the policy options may have negative unexpected side effects, some policy options may work against each other, whereas some may reinforce each other. Some policy options may improve the situation in part of the region, whereas in other parts the situation may get worse. Hence, the definition of sustainable urban policies is not a straightforward task. The effects have to be identified and measured in a transparent way and this calls for advanced systems and methods.

Most cities have a transport model for planning of policies. These models do not take into account the long-term interaction between land use and transport which severely limits their usability for strategic long term urban planning. Some cities have a combined land use and transport model for these purposes but, as strategic models, they don’t produce information on detailed spatial level and cannot, thus, express important effects such as exposures to emissions or noise. They also lack a coherent system for assessing the effects in a systematic and comprehensive way taking into account the environmental, social and economic dimensions of sustainability.

The aim of PROPOLIS is to address the above problems but not starting from scratch. It builds on state-of-the-art urban transport and land use models that operate at a scale which allows us to investigate the long-term (20 years and more) policy impacts - taking account of the feedback from land use, transport and the environment. Studies, which have a narrow spatial and temporal focus - or those, which fail to take proper account of feedback in the urban system - may produce quite misleading results. Furthermore, approaches which ignore land use interaction are likely to overlook important policy effects simply because there is much more inertia in the land use system and by their nature land use impacts tend to be much longer term.

PROPOLIS is also based on a tested system composed of a set of relevant indicators and assessment methodology for the evaluation of indicator values. It will go forward in the following directions, among others:

• it will add also the environmental feedback to the land use and transport system;

• it will increase the spatial resolution of the system by developing GIS-tools;

• it will test and develop the assessment methodologies with close contacts with users and Client Partners;

• it will develop new relevant indicators for evaluation purposes;

• it will use internet technology to communicate with the users and the public;

• it will systematically test and analyse a number of policy options in different European cities with different models in order to end up with generalised conclusions and recommendations for increasing sustainability in European cities.
  
    

Points of departure

Urban sustainability

Sustainable development is usually viewed as consisting of three dimensions

• Environmental and ecological

• Socio-cultural

• Economic

PROPOLIS will build on this theory, although problems with detailed interpretation of the above dimensions exist. Other studies have discussed what the above dimensions mean in an urban context (European Environment Agency, 1995, Europe’s Environment: The Dobris Assessment).

Indicators

Indicators will be used to measure the above three dimensions of urban sustainability. There is a huge amount of literature concerning urban sustainability indicators and the problems that one is likely to face when using them.

Special demands that the PROPOLIS indicators have to fulfil include:

• They should measure relevant aspects (without overlapping) of sustainability and have a sound theoretical background.

• Indicators are used for policy testing. Therefore, the project has to be able to forecast the indicator values into the future. This is an essential difference compared with monitoring indicators.

• The indicators, to be relevant in PROPOLIS context, should be policy sensitive.
  
    

Models and Tools

The project builds on state-of-the-art urban land use and transport models with a sound theoretical background. The environmental feedback will be added to the above models and this will involve new research. In addition, a number of other models will be adapted including emission, dispersion and exposure models. For certain indicators new models have to be developed during the project, these include indicators addressing land consumption, biodiversity, energy use in buildings etc. Modelling work is also needed for the calculation of new economic indicators which will be based on state-of-the-art research in the field (4 FP projects, AFFORD and EUNET, etc). As far as the development of tools is concerned emphasis is placed on the spatial dimensions of the PROPOLIS platform - geographical space is the common factor linking the different levels, scales and stages of analysis (models, GIS, raster impacts, indicators, web map server etc.) Moreover in designing the analytical framework for PROPOLIS and choosing our spatial analysis tools state of the art technology is exploited at many levels.

  

Assessment

There have been discussions about the benefits and disbenefits of cost benefit and multicriteria analysis for years and the discussion continues. PROPOLIS will use both methods. The economic index value for one component of sustainability will be based on cost benefit analysis but the environmental and social dimensions of sustainability are measured using multicriteria analysis. The assessment will take place using an existing decision support tool developed for urban context. The tool will be enhanced to meet the needs of group decision making, coping with uncertainty and citizen’s involvement through internet application.

  

Policies

The partners have experience of testing a number of client defined policies in their test cities. They have also experience of more general and theoretical policy testing approaches. This experience indicates the way towards sustainable urban policies.

Potential policy options are also defined using the external and national networks of the project. Special emphasis is on policies, which have been implemented with success in Europe. Based on the results of previous tests also general rules have been formulated which will help in identifying potential policy options and their combinations. PROPOLIS will introduce a harmonised way to assess the results of policy tests made in different cities with different models.

Part of the tests are the same for all test cities. However, as every city is individual the best policy combinations are likely to differ. This is why optimum policy combinations are sought also separately for each city.

  

The PROPOLIS approach, process to define urban strategies and the system used aiming at policy assessment is illustrated in the figure right. This system is developed and used in order to:

• address the problem defined above;

• add to the state-of-the-art of theories, methodologies and tools;

• define integrated sustainable urban strategies;

• assess and demonstrate the effects of the strategies using a comprehensive approach;

• come to the final conclusions and recommendations for European cities in general and for the case cities in particular.

The system and expected results are described in more detail in the following sections.

  

The Analytical Framework

The Analytical framework is illustrated in the figure right containing the main components and data flows in the system and showing the process from inputs via modelling to outputs.

The input data include policy packages, GIS databases and model databases. Policy packages have to be transformed to "model language" by changing some of the parameters or the model database. GIS databases contain spatial data on zonal boundaries, road and public transport networks, land use categories etc.

In the modelling part the land use/transport models are the driving engines of the system and have previously been calibrated to correspond with the perceived behaviour in the test cities. The sustainability indicator model-component is where most of the research work of PROPOLIS takes place. Each indicator has a mathematical formulation and the indicator values are calculated using this formulation and input data from the land use/transport models, GIS and model databases. For example, the exposure to emissions or noise indicators need traffic volumes from the model, location of the road network and land use categories from the GIS database, algorithms for the generation of microlocations of inhabitants and jobs, and models for emission dispersion, noise propagation and exposure.

The output part consists of sustainability indicator values that are further processed in the sustainability evaluation module (= decision support tool). A lot of other information is stored, as well, in the Background variables module. This is important data (modal split, car mileage etc.) that helps to understand the behaviour of the system but is not used in the evaluation procedure (in order to avoid overlapping indicators), which is based on the indicator set only.

Finally, the presentation module shows the results in a standard form for each policy and has the option to make comparisons between policies and cities and to view disaggregated data (maps, tables) in order to maintain the transferability of the system. The presentation module is based on the GIS-tools to be developed in the project.

One of the goals of the project is to have the process described above work automatically to ensure an efficient policy testing process and the possibility to systematically test as many policies as possible.

  

Results

Indicators

The indicative list of indicators to be produced is presented in the table below.

PROPOLIS, indicative list of urban sustainability indicators.

The indicator values of each policy option will be compared with other policy options, the corresponding values of present conditions, with the target or benchmarking values and with the base scenario (do-nothing or do-minimum) values.

Framework for presentation and comparison of indicator and index values.

Evaluated indicators

The sets of indicator values as such do not solve the problem whether policy A is more sustainable than policy B. This problem is approached with the evaluation tool where each indicator is evaluated through an analytical process where the Client-Partners play an important role.

The evaluated indicators are finally summarised to indices separately for the environmental, social and economic components of sustainability.

The process calls for an extreme aggregation of data, from single indicators, partly derived already from 100 m x 100 m raster cells (tens of thousands per city), via important themes to the final three indices of sustainability. However, the transparency is maintained and it is possible to go from the index level beck to indicator, super-zone, zone or 100m x 100m raster cell level to see how the policy affects, for instance, noise or accessibility in that cell.

  

Maps, tables and other outputs

The system has to be transparent and, therefore, additional disaggregated information is needed. This data is also needed for better understanding of the effects of policies.

The output from the presentation module will include

• maps showing the movements of households and working places,

• maps showing the raster based indicator values by raster cell

• tables showing the values of background variables

• etc.

Background variables include important data that are not used as indicators but help to understand the effects of a policy option. Such data may include the modal split or households or employment / zone.

  

Other results

Other results include reports, web pages, conferences, articles etc. as specified in the Work Programme. The results also include operational software tools and updated urban models with essential new features for the case cities.

  

Conclusions and recommendations

The conclusions and recommendations are based on the policy testing process and on the analysis of the results.

The policy testing process is designed to work interactively with the analysis process so that new policy options are based on the results of the previously tested ones. Gradual improvement and definition of optimum states are likely to be achieved this way.

General conclusions and recommendations are finally made based on the analysis of the results in different test cities. In addition, city-specific strategies are produced.