SCIENCE & RESEARCH Reducing emissions International Transportation (70) 1 | 2018 38 The travel demand impacts of fare-free regional public transport in Germany Public transport, Transport model, Nitrogen dioxide The pressure on city administrations in the EU to comply with European NO 2 limits increases. Therefore, new ideas and solutions that can be implemented short term are sought. One idea being intensively discussed in Germany is providing fare-free public transport in cities. The paper presents likely travel demand impacts of this measure as modelled with the German national transport model DEMO. Results show a significant increase of public transport trips and kilometres under such a scenario. However, passenger car vehicle kilometres would only decrease moderately indicating only small reductions of urban NO 2 emissions due to fare-free public transport. Tudor Mocanu, Christian Winkler, Tobias Kuhnimhof I n Germany, an intensive debate evolves around options for improving air quality in cities by reducing nitrogen dioxide (NO 2 ) emissions. Numerous air quality measuring stations in various cities have repeatedly exceeded the annual limit value for NO 2 (40- mg/ m 3 ) specified by the EU directive 2008/ 50/ EG. The limits were only exceeded at measuring stations located in the vicinity of major roads. Thus road traffic has been identified as a major contributor. Even though in recent years the proportion of measuring station where nitrogen oxide limits were exceeded declined, Germany is still facing the threat of incurring significant financial penalties if the air quality thresholds are not met nationwide. This situation has triggered a public debate about policy measures that are best suited to tackle the issue of NO 2 emissions. Aside from the effectiveness for improving air quality the wider consequences of these measures including their impacts on mobility and public finances are part of the debate. One of the more drastic measures would be a complete ban on diesel vehicles for certain urban areas (e.g. inner cities), as diesel vehicles have comparatively high nitrogen oxide emission rates. However, about one third of the private vehicle stock in Germany is diesels. Hence, diesel bans would have a substantial impact on the mobility of a significant proportion of the population and on residual values of many private vehicles. Therefore diesel bans are very controversial. Among other policy measures aiming at improving air quality in cities, German authorities have proposed the idea of offering fare-free local public transport [1]. Several German cities (Bonn, Essen, Herrenberg, Reutlingen and Mannheim) were suggested for testing this measure and evaluate its efficiency. Later, these plans have been taken off the table mostly because of financing issues. However, the question remains whether this policy measure is suitable and would have the desired effects on traffic and urban air quality in Germany. The concept of fare-free local public transport is not new at all and has been discussed repeatedly in the past, including in this journal [2]. The debate has mostly revolved around the concepts for financing such a scheme. Aside a theoretical debate, there are also practical experiences with fare-free public transport. Several cities around the world have implemented or tested AUF EINEN BLICK Der Druck auf Stadtverwaltungen und Länder in der Europäischen Union zur Einhaltung der NO 2 -Grenzwerte steigt. Aus diesem Grund werden neue Ideen und kurzfristig umsetzbare Lösungen zur Reduzierung der Emissionen gesucht. Eine Idee, die vor kurzer Zeit in Deutschland kontrovers diskutiert wurde, ist die Einführung eines Nulltarifs im Öffentlichen Personennahverkehr (ÖPNV) in Städten. Die möglichen verkehrlichen Wirkungen einer solchen Maßnahme wurden mit Hilfe des deutschlandweiten Verkehrsmodells DEMO quantifiziert. Im vorliegenden Beitrag werden die Ergebnisse vorgestellt und diskutiert. Die Ergebnisse zeigen signifikante Erhöhungen der Anzahl der Wege und der Verkehrsleistungen im Öffentlichen Personennahverkehr. Allerdings gehen die Fahrleistungen des PKW-Verkehrs nur moderat zurück, was auf eher geringe Rückgänge der städtischen NO 2 -Emissionen infolge eines kostenfreien ÖPNV hindeutet. Reducing emissions SCIENCE & RESEARCH International Transportation (70) 1 | 2018 39 fare-free local public transport. One of the most important use cases is the city of Tallinn in Estonia, which has been offering fare-free public transport services to inhabitants since 2013 [3]. Another example of a city currently implementing such an approach is Aubagne (France) [4]. This paper contributes to the current debate on farefree public transport by providing quantitative figures on the travel demand effects of such a measure for a large study area. The paper presents transport model-based results for fare-free regional public transport on the national level for Germany. Methodical approach and scenario definition Estimating the effects of nationwide fare-free regional public transport requires a multimodal national transport model. The DLR Institute of Transport Research has developed a model suitable for this task (DEMO). DEMO consists of several modules covering both passenger and freight transport on the entire territory of Germany, which is divided into more than 6,500 traffic analysis zones. The passenger transport model is split into two complementary sub-modules for short distance trips (trips up to 100 km) and long distance trips (trips of 100 km and over) respectively. This differentiation enables addressing the specific characteristics of these two segments of passenger transport adequately, for example mode choice options: mode options for short distance trips include walking, cycling, car and local public transport; mode options for long distance trips are car, rail, touring busses, long-distance scheduled busses and airplanes. For both modules, travel behaviour parameters are mostly derived from the German national household travel survey MiD 2008 [5] and German value of time study [6]. Further information on DEMO can be found in [7] and [8]. DEMO enables impact assessment for a wide range of policy measures and technological changes in transport supply on travel demand in Germany. Public transport service quality and user costs are important input parameters. For this study, we only used the travel demand module for short distance trips as we assumed that long distance trips would not be affected. The base year for our scenarios is 2011. In addition to a reference scenario, reflecting the transport supply situation as it was in 2011, we defined a fare-free regional public transport scenario. In this scenario there were no costs to all public transport trips in the short distance travel demand module, i.e. for public transport trips up to 100 km. All other input parameters, including public transport travel times and service quality, remained unchanged. Offering regional public transport free of charge is a radical measure and is expected to increase public transport ridership substantially. It is likely that at least in some areas and on some routes the current capacity of public transport services would not be sufficient to absorb the additional travel demand. This would lead to overcrowded vehicles and make public transport less attractive. The scenario we defined in this study is hypothetical and based on the assumption that necessary service improvements are made in order to supply equal service conditions as before. Hence, we do not look at travel demand impacts if fare-free public transport was implemented on top of current services. Instead, our scenario deals with the question of what would happen if the (perceived) system quality remained at current levels but was provided free of charge. Likewise, in this study we do not consider the financial implications of fare-free public transport on transport companies and local authorities. We simply assume that adequate funding will be available to provide the required level of service. The focus of this study is solely on estimating changes in travel behavior and transport demand. Results The modelled impacts of fare-free regional public transport on travel demand included both trip destination and mode choice changes for short distance trips. As expected, this policy measure pulls users towards using public transport services and reduces the shares of other modes of transport. On the national level, the scenario results indicate that the regional public transport mode share would increase from 9 % in the reference scenario to 14 % in the fare-free regional public transport scenario, as shown in figure 1. This translates into additional 5.5 billion annual public transport trips in Germany, i.e. the number of public transport trips would increase by about 66 %. Of the 5.5 billion additional public transport trips per year, almost two thirds are won from car travel, while the rest come from non-motorized modes (walking, cycling). As we limited the modelled travel demand impacts on destination and mode choice we did not consider induced 115 217 68 63 563 522 0 100 200 300 400 500 600 700 800 900 Reference Fare-free PT Distance travelled in bn passenger km per year Public transport Non-motorized Car 9% 36% 55% 14% 34% 52% Mode shares (percentage of trips) Figure 1: Impact of fare-free regional public transport on mode shares and distances by mode (trips up to 100 km) SCIENCE & RESEARCH Reducing emissions International Transportation (70) 1 | 2018 40 trips due to the fare-free public transport; hence, the overall number of trips is the same in both scenarios. As the model accounts for changes in the destination choice, there is an impact on the total (passenger) distance travelled. The distance travelled with public transport is estimated to increase by almost 90 % and thus substantially more than the number of public transport trips, indicating higher average public transport travel distances. This is logical as shifting modes to public transport trips is even more attractive in the case to long trips for which the relative cost advantage is much more pronounced than for short trips if public transport is free of charge. Resulting accessibility improvements are also the reason why total passenger distances travelled including all modes increase by about 8 % in the fare-free public transport scenario. The distance travelled by car on trips up to 100 km is expected to decrease by about 7 %, resulting in a reduction of about 40 billion passenger km per year in Germany. After applying trip purpose-specific occupancy rates, the decrease in vehicle kilometres travelled (VKT) on German roads due to fare-free regional public transport is esti- Figure 2: Reductions in car traffic as a result of fare-free regional public transport Reducing emissions SCIENCE & RESEARCH International Transportation (70) 1 | 2018 41 mated to be about 30 billion km per year. This reduction is not uniformly spread across Germany, but is concentrated on roads in areas with high population density, where a significant proportion of the short and regional travel occurs. Figure 2 shows that the decrease of road traffic due to fare-free regional public transport is more pronounced in urban areas and metropolitan agglomerations (e.g. Berlin, Munich, Ruhr region, Frankfurt etc.). Decreases are smaller on overland motorways where traffic is dominated by long distance trips and freight transport. For major German cities where about 30 % of the total population lives and where air quality issues are most severe the scenario estimates a reduction of about 10 billion VKT per year. This equals to roughly 9 % of current car traffic on trips up to 100 km and 6 % of the total road traffic (i.e. including long distance trips and freight transport). This 6 % reduction allows for a rough estimate of the potential air quality benefits in the fare-free regional public transport scenario. Discussion These results are in line with some of the findings from previous studies, as compiled in [3]. Several cities reported an increase in public transport ridership ranging between 50 and 100 %. Other cities, e.g. Templin in Germany, reported much higher increases in public transport usage. It is important to note that the relative increase in public transport ridership is greatly affected by the public transport mode share before fare-free scheme is introduced. The lower the previous public transport mode share, the higher its price elasticity and the higher the relative increase. On the contrary, the relative increase in public transport ridership due to fare-free service will be smaller in areas with high preexisting public transport use. The presented fare-free regional public transport scenario attempts to shift travel to public transport solely through “pull” measures. These results can also be compared with scenarios combining push and pull measures which also include steps that discourage private car usage [9]. Results from such a scenario, also derived using DEMO, show that an even higher reduction in car traffic can be achieved using a combination of less extreme “push” and “pull” measures [7]. The advantage of such an approach would be less induced traffic overall and no decrease in walking and cycling at the expense of public transport ridership. Conclusions This study presented a fare-free regional public transport scenario assuming identical public transport service quality as today. Despite the hypothetical character of this scenario, the results provide valuable information on possible changes in travel demand. Moreover, because we disregarded possible decreases in public transport service quality, e.g. because of crowding, our scenario represents a maximum scenario with regard to the possible mode shift towards public transport due to fare-free service. The model results suggest that a fare-free regional public transport would be a drastic intervention in the German transport system with far-reaching consequences. Specifically public transport distances travelled would almost double under these scenario conditions. However, the results also indicate that road traffic reductions in major German cities would be moderate: local car traffic would be reduced by about 9 % and overall road traffic by about 6 % in these locales. The expected benefits for air quality can be estimated based on these results. This reduction is possibly sufficient to comply with NO 2 limits; this, however, is uncertain and subject to further investigation. On the other hand it is evident that fare-free local public transport would have significant implications on public finances; specifically, because significant increases in public transport use associated with fare-free services would require substantial expansions of public transport supply in order to maintain today’s level of service (more vehicles, drivers etc.). In light of these results and insights, fare-free regional public transport cannot be recommended as an efficient stand-alone measure to improve urban air quality despite various positive effects that it is likely to have. ■ LITERATURE [1] German Government (2018): Letter from the Minister of the Environment Barbara Hendricks, the Minister of Transport Christian Schmidt and the Chancellery Minister Peter Altmaier to European Environment Commissioner Karmenu Vella. [2] Gondlbach, K. (2014): Kostenloser ÖPNV: Utopie oder plausible Zukunft? In: Internationales Verkehrswesen, Vol. 66, Issue 3, pp. 24-26. [3] Hess, D. B. (2017): Decrypting fare-free public transport in Tallinn, Estonia. In: Case Studies on Transport Policy, Vol. 5, pp. 690-698, Elsevier. [4] Zobel, C. (2010): Aubagne and Etoile Region, France: Free public transport. Available online https: / / www.uclg-cisdp.org/ sites/ default/ files/ Aubagne_2010_en_final_0.pdf. [5] Follmer, R.; Gruschwitz, D.; Jesske, B.; Quandt, S.; Lenz, B.; Nobis, C.; Köhler, K.; Mehlin, M. (2010): Mobilität in Deutschland 2008 - Ergebnisbericht, In: Bundesministerium für Verkehr, B.u.S. (Ed.), Bonn, Berlin. [6] Axhausen, K. W.; Ehreke, I.; Glemser, A.; Hess, S.; Jödden, C.; Nagel, K.; Sauer, A.; Weis, C. (2015): Ermittlung von Bewertungsansätzen für Reisezeiten und Zuverlässigkeit auf der Basis eines Modells für modale Verlagerungen im nicht-gewerblichen und gewerblichen Personenverkehr für die Bundesverkehrswegeplanung, Schlussbericht. In: Bundesministerium für Verkehr und Digitale Infrastruktur, B.u.S. (Ed.), Berlin. [7] Winkler, C.; Wolfermann, A.; Mocanu, T.; Burgschweiger, S. (2017): Modellierung des Personen- und Güterverkehrs in Deutschland als Entscheidungsunterstützung für die Politik. In: Straßenverkehrstechnik, Vol. 61, Issue 8, pp. 551-558. [8] Winkler, C.; Mocanu, T. (2017): Methodology and Application of a German National Passenger Transport Model for Future Transport Scenarios. In: Proceedings of 45th European Transport Conference, Barcelona. [9] Seum S.; Goletz, M.; Kuhnimhof, T. (2017): Verkehrssystemforschung am DLR - Mobil in Deutschland 2040. Teil 2: Die Szenarien des VEU-Projektes. In: Internationales Verkehrswesen, Vol. 69, Issue 2, pp. 78-81. Christian Winkler, Dr.-Ing. Head of the Team Transport Modelling, DLR Institute of Transport Research, Berlin (DE) christian.winkler@dlr.de Tobias Kuhnimhof, Dr.-Ing. Head of the Department Passenger Transport, DLR Institute of Transport Research, Berlin (DE) tobias.kuhnimhof@dlr.de Tudor Mocanu, Dipl.-Ing. Research associate, DLR Institute of Transport Research, Berlin (DE) tudor.mocanu@dlr.de