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English summary
Purpose
The purpose of this report is to analyse measures and scenarios to achieve sustainable passenger transport in Denmark using the microeconomic transport model ALTRANS. The main features of the model are presented in Chapter 2. Chapter 3 has a discussion of how to make the concept of 'sustainable transport' operational. Based on this discussion a set of evaluative criteria is established. In chapter 4 a number of transport policy scenarios are analysed with regard to their performance towards the criteria. Chapter 5 has a more indepth analysis of those scenarios focusing especially on improving public transport service. Finally some aspects of the quality of the model are analysed in chapter 6.The ALTRANS model
The core of the ALTRANS model is a microeconomic model of individual behaviour. This type of model is especially effective to analyse various types of policy variables affecting transport behaviour. The model is based on the Danish National Travel Survey, which includes data on destination and mode choice for a large number of individual trips. The model is constructed in a way so as to calculate the number of cars possessed by each family as well as the number of passenger kilometres travelled by each individual on each mode. The calculation is based on data for previous behaviour combined with information about travel time and costs for all trips. Also included are calculations of the distribution of passenger kilometres on various destinations (a matrix for O-D zones). Since a main purpose of the model was to enable an assessment of changes in the travel time by public transport it was necessary to develop a specific GIS based sub-model. This sub-model calculates travel time by bus and train for all trips based on an extensive set of timetable data for the major public transport providers in Denmark. Calculated travel time is split into time for actual movement, transfer time and waiting time. To enable analysis of transport emissions in future years another submodel has been developed to calculate the composition of the car fleet. By adding this step the traffic performance information produced by the behavioural model can be distributed to cars of different size, age and emission profile for five pollutants, including CO2. The composition model is a macroeconomic model for scrappage of end-of-life vehicles, which is combined with data for the composition of the car fleet in the initial year. The emission projections are calculated as national aggregates. There are no attempts to assess air quality or noise effects since this would require data for route choice, which is not part of the ALTRANS model complex at this stage. The ALTRANS model complex can be used for a variety of analytical objectives including the assessment of changes in outcomes such as passenger transport, traffic or emissions, resulting from changes in several different policy variables. For example changes in motor vehicle speed or travel times in public transport can be stipulated, as well a changes in prices and charges. In addition to changes in direct policy variables also the effect of changes in overall demographic or economic factors in future years can be assessed.Transport and sustainable development
Transport contributes to a number of impacts on the environment, thereby conditioning the overall chances of securing a sustainable development for future generations. Considerable interest has therefore been given to analyse possible strategies and measures to promote so-called 'sustainable transport' solutions. In this project a number of scenarios have therefore been defined in order to assess various policy options for achieving 'sustainable transport' in the passenger transport sector in Denmark. However, a number of difficulties have been identified in the attempt to establish a comprehensive yet operational definition of sustainable transport. Some of the major difficulties are discussed in the report and a simplified and partial approach is established for the further analysis. The focus of this approach is to assess possible reductions in a number of key environmental pressures for which passenger transport is a major contributor. The specific pressures addressed are emissions of Carbon Dioxide (CO2), Nitrogen Oxides (NOx) and Particulate Matter (PM). Those pollutants represent the contribution from transport to key global, regional and local environmental pressures respectively. Thereby the choice of parameters also reflects concerns for both the present and future generations. Nevertheless this obviously entails a substantial narrowing of the full scope of (environmental) concerns in the debate over sustainable development and transport. The more limited approach is mainly due to methodological difficulties inherent in, but not limited to, the particular modelling framework applied to the analysis. The limitations are discussed further in the conclusions from the scenario studies.Scenario analysis
A number of policy scenarios have been defined and analysed. In the analysis the effects of changes in various policy measures on the emission parameters are calculated and held up against impacts on parameters of mobility and costs (time and money) for the travellers. The policy scenarios all address various types of 'behavioural' measures, which means economic measures as well as measures to change transport quality or supply (e.g. quality and speed of public transport). Measures targeting car traffic are included as well as measures towards public transport operations. In one scenario several of those measures are applied in combination. The results show that considerable reductions in emissions are achievable by policies to change travel behaviour, even if it will in general require rather aggressive measures to obtain notable effects (for instance major tax increase or operational restrictions for car travel). Those measures that directly affect the costs of travellers (in money and/or time) are the most effective in terms of reducing overall emissions, compared with measures solely aiming to improve public transport supply or service. Strong measures to enhance public transport service (e.g. a doubling of frequency) are shown to lead to substantial increases in the number of public transport users. However those same measures have a very limited potential to actually transfer car drivers to public transport (the increases thus being due to more travel by existing users or by cyclists and pedestrians) and may even lead to a strong increase in overall emissions especially of Particulate Matter. Moreover it is shown that a combined scenario - combining increased costs for car travellers with improved public transport service - has by far the strongest positive effects on emissions. On the other hand it is shown that restrictive measures also entails the largest increases in costs (time as well as money) for motorists. In the combined scenario restrictions can however be more moderate to achieve a similar level of emission effect as in restrictive scenarios without improved public transport service. It should be noted that all of the chosen scenarios represent rather general measures. With an improved model it would be possible to construct other scenarios with more specific focus (e.g. in geographical terms), in which case the cost/effect ratios most likely could be improved. The distributional effects on mobility and costs that have been examined (in terms of differences between population groups and regional differences) seem relatively moderate. However, measures to restrict car travel typically have the strongest negative impact on people living outside cities (note again that no attempts have been made to design scenarios with geographically differentiated measures). Concerning the overall question of contributing to sustainable transport the above results provide only a partial answer. First of all only a limited range of environmental impacts could be addressed. Secondly, no attempt could be made to compare results with overall 'sustainability' targets, since the model does not allow absolute predictions of future emissions, only relative comparisons between scenarios. Thirdly no attempt was made to weigh together the environmental impacts with the costs in time and money for motorists. Finally no analysis of possible implementation barriers has been made. Nevertheless the overall assessment is that the results of the emissions and mobility/costs analysis provide an important contribution to the understanding of the potential of policies to change travel behaviour in a more sustainable direction.Improved public transport as environmental strategy
The scenarios that address public transport supply and service have been analysed further in order to investigate whether the overall emissions of CO2 can be reduced if public transport is improved. In other words: How and to what extent can public transport improve- ments be used as a strategy to reduce climate impact from the transport sector? One conclusion of the analysis is that a substantial, general increase in the frequencies of all public transport routes would not be sufficient to attract enough car drivers so as to achieve an overall reduction in CO2 emissions from transport as a whole or to obtain an increase in public transport revenues that could offset the increased costs. One reason is that even substantially increased frequency only leads to moderate reductions in travel time as a whole, compared with the large increase of public transport kilometres. Another reason is the strong unwillingness of car drivers to change mode of travel. Another conclusion is that increased travel speed in public transport on the other hand would be environmentally benign, if it is achieved without at the same time reducing the speed of (urban) car traffic. A combined effort to increase speed and frequency of public transport could therefore lead to a substantial improvement in the mobility of public transport users without an overall increase in CO2 emissions from transport. The conditions for this positive effect are however to supply the increased number of public transport kilometres by smaller (and thus more energy efficient) vehicles than the standard ones used today, and to implement better co-ordination between different lines (including between bus and railway lines). The running costs are however most likely to increase as a result of such a combined effort.Quality assessment of the model
An assessment of the model shows that it is well suited to undertake comparative analysis of various policy variables. It can thus be used to analyse scenarios where a basic trend is compared with some alternative trajectories. The price elasticities of the model are shown to be in good agreement with those of other similar models. The results of the analysis of price policy scenarios therefore seem realistic. On the other hand there are some problems with the travel time estimation methodology, especially for public transport. To improve the capacity to forecast travel times correctly, it would be desirable to reestimate the model. Such a re-estimation would however not likely lead to any major changes in the conclusions of this report concerning the environmental effects. The model is not well suited to analyse development in transport over time, e.g. where a future situation is compared with a base year. To make such an assessment using macroeconomic models will be more appropriate. The present model is also not reliable for longterm transport scenarios, since it does not incorporate structural changes in factors such as the location of workplaces or residences.
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