Title of Example

Example

The problems addressed

European cities face common challenges concerning their quality of life: degradation of the urban environment, significant risks for citizens health, traffic congestion causing stress and economic inefficiency, progressive damage of the artistic and monumental heritage. Additional difficulties derive from the lack of integrated tools that allow cities to make balanced decisions on a wide range of issues. The aim of ISHTAR Project is to build an advanced software suite for the analysis of the effects of short term actions and long term policies to improve the quality of the environment, citizens health, conservation of monuments. The suite will include both existing and newly developed models, covering the areas of citizens behaviour, transport, vehicles emissions noise and safety, pollutants dispersion, buildings related atmospheric emissions, health, and monuments degradation. These tools will find an integration in the use of a GIS and a user-friendly interface software. The models suite will be an innovative tool for advanced urban management and will allow the integrated analysis of the various environmental effects of technical and non technical measures. This will represent an attractive alternative to the usual separated analysis of the effects of such measures on the various elements of the urban environment.

Objectives and approach

The integration of a large number of software tools and the creation of specific modules for the advanced simulation of key processes such as transport behaviour and its direct impacts on the urban environment will allow the build-up of an innovative and powerful decision support tool for urban policies optimisation.

The achievement of a high spatial and temporal flexibility in the use of the tool will maximise the possibility of use from local short term actions to widespread long-term policies, thus being of interest for different categories of users. A high level of technical innovation, in terms of both development of new tools needed and balanced integration of these with existing and marketable tools, will create a new method and an innovative software tool for assessing urban policies. Specific modelling efforts will be performed in the representation of policies effects on citizens behaviour, in the integrated 24hr simulation of traffic emissions, noise and safety, in the microscopic analysis of air pollution effects on health and monuments. The maximisation of the European Added Value, deriving from a wide and geographically representative consortium, the development of Stakeholders oriented activities, based on a thorough organisation of dissemination, and the contribution to a widespread socio-economic issue, represented by the decreasing urban quality of life, will originate a potentially huge market for results dissemination and exploitation. The exploitation of the models suite will begin within the Project with the application of the tool to the analysis of measures tested in the seven involved cities: Athens, Bologna, Brussels, Graz, Grenoble, London and Rome. The designed strict coherence with EU Policies for Environment, Transport, and Urban Life Quality, together with the proper liaison with relevant Projects in the whole 5th FP, will guarantee the expected resonance of the project within EC research effort.

Expected Impacts

The key result of ISHTAR Project will be the realisation of a multi-impacts models suite for the assessment of a wide menu of measures for urban life quality. The application of the tool to the measures tested in the involved cities will provide indication of tool usefulness, accuracy, applicability and estimation of impacts on health, environment, monuments. The users involvement will provide evidence of the impact of the performed research. The availability of the ISHTAR suite will allow in future public administrations and consultant companies to run integrated and advanced environmental assessment of short-term actions and long-term policies for the improvement of the urban quality of life. This twofold opportunity can bring environmental and health benefits on one side, and employment opportunity and improved efficiency of the urban system on the other. The main immediate beneficiaries of the new decision support tool will be the local authorities, having the chance of optimising integrated and not conflicting urban policies, and citizens living in cities where the recovery of public health, transport efficiency and artistic heritage will be carefully designed and measured.

Technical elements

The Suite includes both commercial tools and tools purposely developed for the ISHTAR Project. The modelling chain starts from the simulation of the citizens behavioural changes, in terms of movements, attributable to the measure under exam. The behavioural data (the so called ‘Origin-Destination’ matrix’) are then used by the transport model for the traffic simulation. The vehicular flows parameters so produced are then used as input for the direct impact module, which simulates emissions of pollutants and noise and the accidents occurrence. The pollutants emissions, calculated link by link, are transformed on aerial concentrations by means of a dispersion model, while the noise emission levels are input to the noise propagation model that computes the noise level on the road and on the buildings façade. These levels of pollution, noise and accidents risk constitute the basis for the exposure evaluation and then for the health risk assessment. The pollution levels are also used for the assessment of the effects on monuments. A further tool is in charge for the gathering of all the relevant data produced by the previous tools and making the overall evaluation (through a Multicriteria Analysis and a Cost-Benefit Analysis). The models are integrated by an ISHTAR Suite Manager, a user friendly interface and a commercial Geographic Information System.

The integrated modules

The Cellular Methodology

The Suite standard starting model is represented by the Cellular Transport Methodology (CTM) , a Software tool developed by ISIS (Italy) that simulates the effects of policies and measures on citizens behaviour (in terms of movements). This model is the first ring of the model chain and on its ability of reproducing the different effects of different actions depends the capability in assessing the effectiveness of the measures to be implemented.

The result of the CTM consists in new O-D matrices representing the modified behaviour of the population following the implementation of the postulated measures. This methodology produces people density patterns for the city “cells” (city portions) by estimating the in-out flows taking into account the total mobility demand and the distribution of attracting and generating points within the city. The O-D matrices produced by this tool are the primary input for traffic models. A further output of this model is the ‘present population’ estimate (split into groups for age, sex, activity) within the ‘cells’ during the day. This is an essential data for the exposure assessment.

The transport model

The second ring of the chain is the transport model, which, on the basis of the O-D matrices provided by the CTM or by any other tool available to the user, simulates the movements distribution within the city network. After a review of existing models, and taking into account the Suite needs, the traffic model ‘Metropolis’ has been chosen. This ‘tactical’ model, thanks to dynamic simulation of congestion allows a better representation of vehicular flows and speeds. In particular Metropolis is able, using the same data as a ‘strategic’ model (a ‘static’ model used for wide temporal and spatial scale), to quickly reproduce dynamic simulations.

A limit of Metropolis Software is represented by the absence of the multimodality (only the private vehicular flows are simulated, the other movement ‘modes’ are not considered). However this limit has recently been overtaken with the integration between Metropolis and VISUM by PTV (D), a strategic model, that allows to simulate multimodal movements. The resulting software, denominated VISUPOLIS, is the software tool that is being integrated within the Suite, as it can provide all the data needed by downstream models. In particular the congestion description allows to simulate the different path and departure time choice, the accumulated delay and the path chosen. This tool will be tested through the Paris case study.

In any case, the city administrations not interested in implementing this tool, will be able to use their own traffic model providing the traffic data (at least the speed and flows for each link) in a compatible format.

Direct impacts module

The direct impacts (pollutants emissions, noise emission, accident occurrence) module used within the suite is TEE2004 (Transport Energy and Environment), developed and provided by ENEA and ASTRAN srl (Italy).

This code has been developed and adapted for the ISHTAR Suite, refining the vehicle kinematics algorithms, and including new models for the estimation of cold emission distribution, parking process, emissions of new categories of pollutants, and finally for noise emissions and accident occurrence.

As it regards the kinematics, TEE code can calculate link emissions starting from standard correlations based on average speed or from instantaneous emissions data, allowing emissions detailed calculation, according to the traffic input data available, either from measurements or from traffic models. Moreover the model includes an innovative solution for taking into account the effects of vehicle kinematics, based on the reconstruction of the speed cycle along the link on the basis of key link varaiables such as traffic density, average speed, link length and the fraction of green time at intersection.

As it concerns the estimation of the effects of cold emissions spatial and temporal distribution, TEE offers alternative solutions for the user, according to the more or less disaggregated information, allowing in any case to distinguish different situations.

The parking process algorithm provides an approximated but meaningful treatment of traffic flows from and to parking areas and allows to locate cold vehicles emissions in space and time and a greater accuracy in the estimation of evaporative emissions distribution.

TEE2004 contains also two totally new new sub-models: the noise emission model, (sensible to vehicular flow and speed, heavy duty vehicles presence and slope) and the accident occurrence model, that calculates the total number of accidents involving only vehicles or vehicles and pedestrians.

Pollutant dispersion module

The pollutants dispersion can be calculated with one of the two tools provided by ARIA Technologies (F) depending on the spatial and time scale. For urban scale and long term analysis the suite will rely on ARIA Impacts, while for mesoscale and short term events ARIA Regional will be the reference model. ARIA Impacts is a gaussian model generally used for assessing long term and urban scale measures: it treats gaseous pollutants and particulate matter but does not consider chemical reactions in the atmosphere. A ‘canyon’ model is being purposely developed for the Suite; it allows to take into account the air recirculation and the pollutants accumulation within the street canyons. ARIA Regional is a complex, non idrostatic, eulerian model that can simulate reactions in the atmosphere. The reference scale vary between 30 and 300 Km. This model is also capable to analyse pollution episodes and to forecast repetitions. The considered pollutants are: CO, NOx, SO2, VOC, PM. Both models are completely integrated within the suite and provide data needed for calculating impacts on monuments and health.

Noise propagation module

The model that is in charge of the noise propagation simulation (noise emission is calculated by TEE2004) is a commercial software tool: Soundplan, by Braunstein & Berndt GmbH, Germany. Soundplan has been chosen because it doesn’t build just noise grids, but it calculates the noise levels on the receivers, as indicate by EC directives. Soundplan can simulate also the effects of the introduction of noise barriers and other methodologies for noise reduction. However this is possible only with a detailed three dimensional reconstruction of the area under analysis.

Health impact module

This module is provided by WHO and consists in two parts: the first part has been purposely developed for ISHTAR and is a GIS application that calculates the citizens exposure to air pollutants and noise taking into account the data provided by the upstream models. In particular it analyses the noise and pollution maps, and, overlaying them with the population activity and movements during the day, it estimates the disaggregated exposure of population groups by gender, age, and activity during the day. This module represents a real innovation in the field of exposure assessment: so far the exposure has been mainly calculated for a whole city during one year, while this tool can assess exposure of more or less small groups for short periods, even hour by hour.

The other part of this module consists in a software tool for the health risk assessment that calculates the health impacts taking into account the exposure to noise and pollutants and the accident occurrence calculated by TEE2004 and applies the dose-response curves available in literature.

Impacts on monuments

The pollution maps produced by the dispersion model are not only applied for assessing health impacts but also impacts on monuments. The tool that calculates the monuments impacts is developed by ENEA and PHAOS (GR) and, on the basis of pollution levels and the material constituting the monuments, calculates the crust formation or the lost of material, plus the cost of maintenance and/or restoration.

Overall Analysis

The overall evaluation of the analysed measures is made by a software developed by LMU-TraC (UK). This tool is based on two methodologies: a Cost-Benefit Analysis and a MultiCriteria Analysis. The module gathers the data from the upstream tools and specific data regarding the measures to be implemented and by assessing them in terms of money (CBA) or parameters (MCA) makes the measures comparable among them.

The integration

The integration software (including the specific Ishtar Suite Manager that controls the run execution) has been developed by INRETS() and manages the use of the Ishtar Suite Interface (for input and output operations at ‘suite level’) and the launching of the tools in the right order and with the proper objectives (e.g. the number of runs of each tool and parameters affecting the tools tasks).

The tools launching is made by ‘software connectors’, i.e. software tools that manage the data exchange among the tools and the Ishtar Suite Database (the adopted format of exchange is ‘xml’). A commercial Geographic Information System (Arc View ()) is used for inputting and outputting the geographic data or the geo-referenced data (link data, area data). The GIS is used as well for data elaboration, mainly in the exposure calculation. The Suite will ahve a user friendly Interface that allows the Suite utilization also by common users, like city planners. The basic architecture of the suite is shown in Figure 1.

Fig.1 : Architecture of the ISHTAR suite modules and data

Application and validation

So far the Suite has been used, in a disaggregated way, and will be used, once integrated, for demonstrating its applicability and validity to the following case studies:

Athens

The case study ‘Attiki Odos’ addresses the new roadway construction, Attica Periphery Road, which is assessed in terms of traffic, toll strategy and pricing, and environmental conditions (as air pollution primarily and in certain areas in terms of noise).

Bologna

The Bologna Provincial Authority case study concerns the evaluation of infrastructure scenarios for the city of Imola with reference of alternative road paths.

Brussels

The aim of the Belgian case study is to prepare the implementation of traffic banning measures in the Brussels area, according to the Plan Ozone of the Federal Government.

Graz

The Austrian case study – coordinated by Graz University of Technology () - is based on the traffic and noise impact evaluation of a 600 m long new road tunnel causing a relevant local traffic rerouting.

Grenoble

Grenoble case study is intended to monitor the effects of the installation of reserved lanes for public transportation and new traffics lights on boulevards with heavy traffic. The site covers the Boulevards over a length of one kilometre, the time scale is 1999 – 2000.

Paris

Every September 22nd the city of Paris takes part in a ‘car free day’. This typical short term event will be modelled with the ISHTAR suite of modules.

Rome

This large scale case study involves the internal ring (including the Rome Limited Traffic zone), which will be transformed in a road traffic collector towards intermodal nodes with radial railway lines.

Conclusions

The ISHTAR Suite represents a breakthrough in the field of decision making support tools. So far the models used in this sector (generally just traffic, emission and dispersion models) were used separately and, with many difficulties, the data exchange between models was done manually, handling considerable amounts of data. A really integrated Suite, like ISHTAR is, allows the comparison of scenarios taking into account the effects on health, air pollution, noise, people mobility and traffic congestion, transport related economic competitiveness, safety, maintenance of infrastructures, built environment and cultural heritage. These characteristics will make the ISHTAR suite one of the reference tools to be used for the design and the assessment of urban environmental policies based on sustainable transport systems.

Key References

• ISHTAR : an Integrated Models Suite for Sustainable Regional and Town Planning – by P. Hoglund (KTH Stockholm) and E. Negrenti (ENEA) – Cities of Tomorrow Conference – Goteborg (S) – 23-24 August 2001

· ‘ISHTAR’ : ‘integrated software for health, transport efficiency and artistic heritage recovery’ – E. Negrenti - ENEA - Accepted for the ‘Transport induced Air Pollution conference – Boulder (CO), September 2001’

· ISHTAR Project : Building a Model Suite for Urban Sustainability – by E. Negrenti – ENEA - 21st ARRB/11th REAAA Conference ‘TRANSPORT - our highway to a sustainable future’ – Cairns – 18-23 May 2003 – Conference Proceedings

· ‘ISHTAR Project: building a models suite for urban sustainability’ - Emanuele NEGRENTI and Alessandro AGOSTINI (ENEA) , Pierre-Olivier FLAVIGNY (INRETS) - Environment and Transport conference – Avignon - June 2003 - Le Collections de l’INRETS – Actes INRETS n. 93 – Vol 1 – p. 123 –ISSN 0769 0266 – ISBN 2 85782 589 7

Last Updated

13th January 2005