Transport modelling in the new Member States is a difficult job, for model developers are faced with poor data availability and a lack of adequate tools and instruments. As a consequence, policy makers can be concerned about the appropriateness of the impact assessment of socioeconomic and environmental indicators. Moreover, there is a lack of consistency in common transport modelling between bordering countries, i.e. at European regional level. Therefore, it is of crucial importance for developing common European transport models, to identify the immediate user needs and main bottlenecks on transport modelling in the new Member States. The new Member States have a particular interest to set up, enhance and/or link transport models at national and/or regional levels based on their needs. A new handbook tries to support transport modellers and policy makers by basing the transport models for the new Member States on common best practice principles. This approach will bring advantages both in terms of costs and of performance. Efficiency and effectiveness will be achieved by applying proven methodologies for design, development, data use, practical use and maintenance of the models. Besides, best practices will give an example for linking models (bordering territories) and data aggregation (checking or feeding national models with data from regional models, or European models from national models). This handbook provides guidance and an incentive for new Member States to progressively move towards its application, as they find it appropriate. This should in turn facilitate the linking of bordering models and/or aggregation of models, thereby paving the way for a bottom-up path to establishing better-grounded transport models at the more aggregate (national or EU) level. The high-level goal of this handbook is to support transport policy in Europe by defining common good practice principles for national and regional transport modelling. These principles are to satisfy the immediate needs of model developers in the new Member States, and contribute to establishing a standardized approach for transport modelling in the European Union. The handbook is the result of the European project MOTOS (Transport Modelling: Towards Operational Standards in Europe). The full-size version of the handbook is available in hard copy format and on the MOTOS website: http:/www.projectmotos.eu. The process used to create the handbook required first to described the user needs in the new Member States and current state of affairs within the field of transport modelling. The MOTOS project has put considerable effort into determining the user needs of model developers and policy-makers. The user needs analysis was supported by targeted workshops (four) in the new Member States and questionnaires. The questionnaires included an extensive description of state-of-the-art of transport modelling and a number of best practice examples were collected and described. Finally all the information was put together in one handbook, resulting in a document containing more than 400 pages. Added to this document are different hyperlinks to make it much easier for the user to find the information they are looking for.