Background The City of Kaliningrad's authorities are increasingly concerned by the city’s growing car traffic, leading to growing air pollution. The main urban pollutants involved are nitrogen oxides (NOx), dust,particles and hydrocarbons, especially benzene. A strategy of transport network development within the city’s general development plan has been set up. This strategy is aimed at traffic stream optimisation and the reduction of traffic-related pollutant air emissions. Among the main options considered are: (1) the definition of limited access areas (e.g. for pedestrians, bikes, authorized vehicles only), (2) restriction on roads (e.g. creation of bus lanes), (3) incentives to get very old cars out. Objectives The project's objective was to develop a modelling tool to be used by the beneficiary, ECAT-Kaliningrad (ECAT), to study the patterns of air pollution related to road traffic in Kaliningrad. Through the application of emission-reduction strategies, the project sought to reduce traffic-related air pollution in the city traffic 'hot spots'. The initiative would also support the effective control and monitoring of the transport sector’s impact on the environment through the following: Development of traffic, meteorological, emission and air-pollution dispersion models, taking into account urban effects and site characteristics. Gathering of geographical data in a GIS-type environment. Collection of traffic data, including flow observations and statistical data on traffic demand at various times of typical days. Development of maps of emissions on a grid. Results The KALAIR project constructed modeling tools to study the mechanisms on air pollution caused by traffic. The modeling tools take into account urban effects and site characteristics. Physical geographical data (terrain, land-use) was gathered in a GIS environment, together with geographical data on the road network, urban landscape and human geographical data on population and transportation demand. Traffic data was collected, including observations of vehicle flow and statistical data on traffic demand at various times of typical days. The data was synthesized through a traffic model and emissions from traffic flow were computed using the most recent techniques applied in Europe for this type of problem, with special focus on critical substances. The modeling system (ARIA REGIONAL) implemented integrate the following tools: • CARUSO Traffic Assignment Model • TREFIC/EMITRA Emission Model • SWIFT Meteorological Model • Dispersion Models: FARM (Eulerian model)/ARIA IMPACT (Gaussian model. The tools were validated through on-site experiments. These involved comparison with available air pollution data from continuous monitoring stations, as well as with specific field experiments using passive samplers. Additionally, the ECAT experts investigated the impact of changes in fuel composition, improvements in the car fleet quality, increases in public transport, and changes in the city traffic scheme, including rights of way. Future traffic scenarios in Kaliningrad have been evaluated with the configured modeling system in order to evaluate various emission abatement strategies to reduce air pollution from traffic. The average target year for the implementation of the different traffic scenarios was set to year 2015. Six different scenarios were elaborated by grouping the spectrum of policy guidelines emerged during meetings with the Stakeholder’s reference group: 1. Business as usual (Reference scenario) 2. Construction and renovation of bridges and bridge passages 3. Development of city road network and optimization of traffic flows 4. Improvement of public transport 5. Renewal and improvement of the Kaliningrad vehicle fleet 6. Improvement of the fuel quality This type of research, i.e., analyses of traffic flows and air pollution dispersal modelling at the city scale is fairly widespread in Europe and elsewhere in the world. However, it is relatively unusual in EECCA countries (Eastern Europe, Caucasus and Central Asia) – indeed, prior to the launch of this project only St.Petersburg had a similar system. Thus the project is innovative for Russia and the region. It has a high demonstration value and excellent potential for transfer. Further information on the project can be found in the project's After-LIFE Communication Plan (see "Read more" section).