Title of Example

Example

1.0 HEAVEN and the link mobility – environment in ROME

STA, the Mobility Agency of Rome, together with the local environmental authorities developed the HEAVEN IST project in order to investigate the link between traffic and atmospheric pollution, to verify the feasibility and the effectiveness of emission control measures and traffic management policies, to monitor air quality conditions.

The main purpose of the HEAVEN project was a real time description of traffic, pollutant emissions and concentrations on a demonstration area of the city of Rome. All the information were collected in a common repository accessible to professional users and decision-makers that will provide support to evaluate the environmental impact of Traffic Demand Management Strategies (TDMS).

For the demonstration area, HEAVEN delivers in near real time:

· Traffic flows and speed every five minutes on the whole network of the demonstration area, combining traffic measurements where available and traffic assignment with traffic models;

· Traffic related air pollutant emission maps every five minutes. Emissions will be evaluated using models both based on average speed and on speed cycle on each link;

· Air pollutant concentration maps at the road level on a grid that covers the whole demonstration area with 60 metre spatial resolution and one hour time interval.

Besides, HEAVEN is a DSS (Decision Support System) whose aim is to evaluate the environmental impact of TDMS through off-line scenario analysis, to support decision makers and professional users in taking the most environmental effective policies though both the scenario analysis and the realisation of a common repository where historic data on traffic emissions and concentrations are stored.

HEAVEN project in Rome is a succesfully history. Rome is continuing the work on the HEAVEN prototype to make it suitable for continuos use on a standard basis with the full support of the Municipal Authority.

Request for further financing support was forwarded to the Environmental Italian Ministry that is already appreciating the efforts towards the realization of the prototype itself and it guarantee its support for the HEAVEN application in the future with the new SICOTRAVIA Project.

Besides, work with World Health Organisation is continuing to analyse the health applications on the outcomes coming from HEAVEN chain inside the ISHTAR EU RTD Project. HEAVEN permitted the creation of the logical data exchange process: this now forms an important platform for future studies. At the end of the project the Health component, is representing one of the most significant achievements in terms of potential development of the system.

1.1 HEAVEN System Concept

The HEAVEN DSS combines near real-time traffic flow information into emission and dispersion models so as to analyse the contribution of mobile sources to air quality and noise. In order to estimate emissions based on current traffic levels and on planned demand management scenarios, the system can operate on-line, based on current traffic and environmental information, and off-line, based on planned traffic and environmental conditions and pre-defined TDMS.

“Before” the implementation of the HEAVEN system in Rome the traffic data were available only on monitored links while on the rest of traffic network the only information available was represented by the traffic flows obtained through the O/D matrix assignment procedure; with the O/D matrix updated every five years. On the pollution side the only data available were the one obtained by the 12 measurement stations located within the city. Moreover, emission maps were produced yearly and because of the lack of a specific tool they were affected by a large personnel factor. Fig 5 shows the existing system before HEAVEN implementation.

Fig 1. “Before” HEAVEN

“After” the implementation of the HEAVEN system, the total number of monitored and modelled links in the demonstration area is equal to 739, pollution concentration are calculated hourly for four different pollutants (CO, C₆H₆, NO₂, PM₁₀) in 4,356 points and emission and concentration maps are produced on-line. Fig. 4 shows the Rome DSS demonstrator and identifies the main processes, data stores and data flows.

Fig 2: “After” HEAVEN

The overall structure of the HEAVEN DSS consists of two main modules: traffic and air quality modules, the latter divided in emission module and dispersion module. The three modules exchange input and output data between them and external existing systems. All data are gathered in a common database and information is represented on a friendly and easy to use interface.

Moreover a scenario module allows off-line analysis of the environmental impacts of specific TDMS defined by the user.

1.1.1 HW implementation

The Rome DSS is based on a distributed architecture. Different workstations are dedicated to run different software processes categories as follows:

· Front end SW modules devoted to connect to external interfaces and data sources

· traffic & pollution processes devoted to traffic modelling and to pollution modelling

· scenario & HMI processes devoted to scenarios management and operator interfaces

The workstations are connected on a Local Area Network (LAN) linked on a Wide Area Network (WAN) with the external interfaces. The architecture adopted allows for system scalability in case the computing power of any of the workstation would not be sufficient for the on-line operation of some processes.

All data are stored on relational databases served by a system database server. For compliance with databases already available by STA the adopted database engine is Oracle.

The following figure shows the LAN diagram for the DSS system and the real implementation in Rome.

Fig SEQ Fig._ \* ARABIC 3. HEAVEN implementation for the Rome DSS

1.1.2 Operation and Function of the DSS

The system provides hourly concentrations of carbon monoxide (CO), benzene (C₆H₆) and particulates (PM₁₀) on a demonstration area of 16km², with a spatial resolution of about 60m.

The Traffic Control Centre located at STA, gathers traffic information (flows and average speed) every five minutes on almost half of the demonstration area primary road network.

The air quality network of the Municipality of Rome provides information on an hourly basis of pollutant concentration in the area.

Through these two systems, it is possible to achieve a good description of the traffic on the primary road network and to have local information on air quality.

Before HEAVEN in Rome, no dispersion models were applied continuously to provide an extensive description of air quality.

The HEAVEN demonstration area is located inside the Ring Road in the North-East part of the city and it can be considered as a representative part of the entire urban network. In fact, it contains a wide green area (Villa Ada, Villa Torlonia), several radial corridors (Via Nomentana, Via Salaria, Lungotevere) and the inner zone, which is made up of high density neighbourhoods.

The traffic network is represented by a graph made up of 51 centroids, and more than 400; 116 of them are monitored by means of automatic measuring stations.

The aim of the traffic modelling module is the estimation of the equilibrium flow distribution on the network. The traffic module consists of three different sub-systems that are combined together to evaluate the state of the system; they are:

- Traffic counts sub-system

- Traffic assignment module

- Observer module

The traffic assignment programme TransCad is a full-featured Geographic Information System (GIS) designed specifically for planning management, and the analysis of the characteristics of transport systems.

On the HEAVEN network, a deterministic user equilibrium model has been performed to evaluate the equilibrium flow distribution of the system. In order to obtain a realistic configuration of the system, the flow function of vehicles on the links have been calibrated with the data detected by the measurement stations.

The programme is completely integrated with the main database of the Traffic Control Centre and by means of its Graphic User Interface (GUI) can display trends of measured data (flow, speed and occupancy). The “observer module” (developed by STA) whose aim is to integrate traffic data available for the subset of monitored links with the assignment flows. Such process obtains a unique and realistic flow value on each link of the network.

Moreover, traffic data produced are used as input information for the transport emissions module (TEE) in order to evaluate pollutant emissions on links.

1.1.3 Air quality modelling

The air quality modelling has been implemented at urban scale allowing a high spatial resolution description of pollutant concentration on an hourly basis.

In Rome, Air Pollution Modelling tools are used for:

• Traffic-related emissions calculation (TEE software, provided by ENEA)
• Concentrations calculation (ADMS)

TEE is a computer model for the calculation of consumptions and emissions from vehicular traffic at ‘microscopic’ (street) and ‘macroscopic’ (city or region) level; TEE model calculates emissions on links where information on driving pattern is available. On links where only the average speed and traffic flow are known, emissions are also calculated by TEE by using the classic COPERT methodology. As an advanced alternative TEE can correct the emissions estimated from average speed by means of an internal function (Kinematics Correction Function) that intends to describe the overall effect of speed variability along the link, and depends on 4 variables : traffic density (vehicles/km), green percent time at traffic light, link length and average link speed. The sensitivity to density is largely the most important one.

The most relevant validation activities were initially performed on the basis of CO pollution levels measured in Rome within the ESTEEM Project (1998).

New results obtained within the evaluation activities of the HEAVEN project are coherent with the previous validation studies.

The usage of the kinematics correction has allowed to predict very well the CO peaks along the day (see figures 5 and 6) while the adoption of the classic average speed approach led to significant underestimates.

ADMS-Urban is a pollution model developed by CERC (Cambridge Environmental Research Consultants) with the assistance of the United Kingdom meteorological office. It is linked to external GIS and visualization tools and represents a comprehensive tool for tackling air pollution problems in cities and towns. It can be used to examine emissions from 4,100 sources simultaneously, including road traffic, industrial and "background grid" emissions and requires relatively simple meteorological inputs.

1.1.4 Decision support system

In the off-line mode, HEAVEN is used to assess the environmental impact of TDMS. With this aim a scenario interface has been planned in order to allow the decision makers and professional users to easily handle all of the traffic and environmental parameters needed to define TDMS and their impacts on environment.

An user friendly scenario allows the definition of the TDMS, deciding mobility intervention (road closure, traffic banning to certain categories, speed reduction), renewal of vehicle fleet.

1.1.5 Operator interface

An user friendly operator interface has been realised in order to display real time traffic emission and dispersion data on the map of the demonstration area. Common tools such as zoom in zoom out, information on links, time of day, vehicle fleet and meteorological data are provided to the user.

1.1.6 Information Presentation

The Man Machine Interface provides the user of the Heaven system with a friendly instrument for monitoring the near real time environmental situation along the study area in Rome.

The procedure that needs to be applied to display the information consists in defining which kind of information the user wants to analyze (traffic parameters or emissions or concentrations) and to select the information option on the main toolbox; than to select the interested link: a pop-up window with the request information will be then displayed on the screen as shown in fig. 13.

In addition, the user has access to statistical and historical environmental data reported on a day basis and plot in diagrams; otherwise, it is also possible to access the following historical data: traffic counts (on a 5 minutes basis), traffic assignment, meteo, emission and pollution concentration (all on an hour basis).

Fig SEQ Fig._ \* ARABIC 4. HEAVEN user interface

Figure 5 : comparison between meeasured and calculated (TEE 2004 with kinematic correction + ADMS) CO concentrations (hourly differences)

Figure 6 : comparison between measured and calculated (TEE 2004 with kinematic correction + ADMS) CO concentrations in Rome HEAVEN system

References for TEE transport emission model

· The ‘Corrected Average Speed’ approach: a simple and accurate way for calculating traffic emissions – E. Negrenti – 4^th International Symposium ‘Transport and Air Pollution’ Avignon 9 - 13 June 1997

· The ‘Corrected Average Speed’ approach in ENEA’s TEE model: an innovative solution for the evaluation of the energetic and environmental impacts of urban transport policies -–E. Negrenti – Highway and Urban Pollution – Baveno (I) May 1998.

· The ‘Corrected Average Speed’ approach in ENEA’s TEE model: an innovative solution for the evaluation of the energetic and environmental impacts of urban transport policies - Emanuele Negrenti ENEA Italy - 19^th ARRB Conference – Sydney – December 1998.

· ‘Integrating Average Speed Emissions and instantaneous emissions sensitivity. An Innovative approach for the assesssment of urban transport policies’ – E. Negrenti et al – Transport and Air Pollution conference – Graz – 31 May - 2 June 1999

· ‘Integrating a new traffic emissions model with an urban dispersion model: an innovative approach for integrating urban transport policies and air quality management in the city of Rome’. Emanuele Negrenti ENEA, Gabriele Zanini ENEA, Maria Petrova Kolarova - NIMH Bulgaria (under contract to Enea) – Air Pollution 99 Int’l Conference - San Francisco – July 1999

· “Speed variability modelling in urban transport emissions inventories” - E. Negrenti - ENEA , A. Parenti ASTRAN, B. Janis - AGIP Italy, E. Rebesco - EURON DIPEN – San Donato Milanese - Conferenza Internazionale TERA 2000 - Milano – Ottobre 2000

· ‘Relevance of speed variability modelling in urban transport emissions inventories’ – by E. Negrenti - ENEA, A. Parenti - ASTRAN, B. Janis - AGIP, E. Rebesco - EURON DIPEN - World Conference on Transport Research – Seoul – Korea - July 2001 – 2001 WCTR Proceedings

· ‘Modelling vehicles kinematics relevance in network based - urban emissions inventories’ - Emanuele NEGRENTI (ENEA) , Antonio PARENTI(ASTRAN srl) - Transport and Air Pollution Conference – Avignon - June 2003 – Le Collections de l’INRETS – Actes INRETS n. 92 - Vol.1 – P. 73 – ISSN 0769 0266 – ISBN 2-85782 588 9

Last Updated

13th January 2005