For the timeframe 2004 to 2025, the Federal Ministry of Transport, Building and Urban Development (BMVBS) projects an increase in passenger transport of 2.7%. The number of motorized and non-motorized trips in Germany will thus rise from 100.3 to 103.1 billion. Motorized transport will grow by 7.1 percent. Traffic volume, the most important parameter in determining transport development, will increase even more strongly due to the disproportionally large growth in long-distance travel and increasing journey distances, namely by 17.9 percent, to 1,368 billion passenger kilometers.
Transport demand is an expression of human requirement for social participation. Each individual is daily confronted with decisions concerning their chosen location and mode of transport. An increasing travel demand requires concepts which ensure the mobility for each individual for social participation while ensuring a sustainable transport strategy.
The DLR Institute of Transport Research (IVF) is working on several projects in which scenarios for sustainable transport development are developed and analyzed. In the process, potential transport measures are tested for their effectiveness. Against this background, the IVF has developed the TAPAS transport model, which examines future demand in passenger transport.
TAPAS makes it possible to evaluate possible future developments in transport demand under variable framework conditions, that of demographic change, for instance, or altered income structures. The model serves to map and assess measures influencing infrastructure and demand in passenger transport, for example cost changes in the transport sector, or an alternative service in local public transport. Furthermore, important findings on the acceptance amongst the population of innovative vehicles, fuels and mobility concepts are to be expected from TAPAS.
As a microscopic model, TAPAS starts off from the transport behavior of individuals. Empirical spatial and structural data, information on time use as well as indications on the use of various modes of transport form the basis, via TAPAS, for a realistic mapping of current and future demand. The time use data of the current version of TAPAS come from a time budget survey carried out by the Federal Statistical Office in 2001/02. In the process, 12,600 people from 5,400 households recorded their daily routines, including transport, in diaries. Each diary reported the type and duration of each activity at ten minute intervals. In addition, socio-demographic characteristics and the household equipment of those surveyed were compiled.
The representative survey on everyday mobility behavior in Germany, “Mobility in Germany (MiD)” is a further important data source for TAPAS. In particular, the chosen mode of transport and travel distance can be gained from the survey results. MiD was carried out on behalf of the BMVBS in 2002 and 2008, and includes the behavior of around 60,000 people in the form of travel diaries enriched with additional socio-demographic information.
TAPAS uses a synthetic population for a specific target area as an essential basic element. On the basis of available data for the area to be examined, it is determined how many people live there, amongst how many households they are distributed and which socio-demographic characteristics they exhibit. For each person of the synthetic population, the diaries from the time budget survey to subsequently determine, which activities they pursue within a workday.
Age, gender, employment status and availability of a car are decisive criteria for the formation of daily activity plans. Trip chains arise which describe a series of location changes resulting from the succession of activities throughout the day. On the basis of these trip chains and the personal and household characteristics, TAPAS offers numerous possibilities to investigate measures and their impact on individual road and transport users within the model.
Activity plans for individual members are on hand as a result of the calculations. These include the trips origin and destination, the distance covered, the trip purpose and the chosen mode of transport. From this, statistics can be derived and further processed to provide information on expected transport demand.
What is TAPAS used for?
TAPAS is an important component of the range of analytical instruments which map and assess measures and impacts of a future sustainable transport policy. For example, TAPAS was applied within the research project RENEWBILITY, “Stoffstromanalyse nachhaltige Mobilität im Kontext erneuerbarer Energien bis 2030”, carried out by the IVF and the Öko-Institut. In the process calculations were made comparing passenger transport demand in 2005 and 2030 in the Berlin, Hamburg, Braunschweig and Main-Rhön regions. Conclusions could be drawn from this about transport development in the whole of Germany.