SCIENCE & RESEARCH Traffic safety International Transportation (70) 1 | 2018 30 Streetcar accidents in built-up areas Accident occurrence and measures for improving-safety Streetcar accidents, Tramways, Safety audits, Intersections, Track beds Around 4,100 streetcar accidents with personal injury in 58 German cities in a threeyears-period were analyzed. Pedestrians make up by far the largest share of fatalities and cases of serious injury. Cyclists also feature disproportionately strongly in accidents involving serious injury. Pedestrians suffer serious accidents disproportionately often on stretches of road and at streetcar stops. Streetcars themselves are main responsible in only 15.7 percent of the analyzed accidents. Serious accidents occur, in particular, at signal-controlled intersections and on threeor four-lane roads with a separate streetcar track bed in the middle. Jean Emmanuel Bakaba, Jörg Ortlepp T here are streetcars in 60 large German cities. The numbers of accidents on roads in built-up areas and, in particular, the numbers of fatalities and serious injuries have been falling for years [1]. However, this positive trend does not extend to accidents involving streetcars. In absolute terms, the numbers of streetcar accidents and the associated casualties have been stagnating for years. Accident and safety comparison Bauhaus University Weimar was commissioned by the UDV (German Insurers Accident Research) to carry out a comprehensive study of the accident statistics, based on around 4,100 streetcar accidents in 58 German cities (Figure 1) in the period from 2009 to 2011 [2]. The aim of the research was to find out how, where and when the various road user groups are involved in accidents with streetcars, the consequences of these accidents and what measures can be taken to improve this situation. Three-quarters of the road users killed in accidents involving streetcars are pedestrians, and around 16 percent are cyclists (Figure 2). Pedestrians also make up by far the largest share (37 percent) of those suffering serious injuries, followed by the occupants of cars and cyclists. Streetcar accidents are significantly more serious than accidents involving cars and buses overall (Figure 3). To assess safety, the accidents were studied in relation to the distance covered and number of people transported [3]. The accident cost rate for streetcars is up to eight times higher than it is for cars in relation to the distance covered but only a fifth of that for cars in relation to the number of people transported (Figure 3 right). If only the number of fatalities is considered, streetcars are no better than cars in terms of the number of people Figure 1: Investigated cities with streetcars in Germany All sources in this article: UDV Traffic safety SCIENCE & RESEARCH International Transportation (70) 1 | 2018 31 transported and 35 times more unsafe in terms of the distance covered. Network analysis and affected infrastructures The network analysis carried out revealed that track beds in the middle of the road were significantly less safe than track beds at the side of the road or off-road track beds. Threeor four-lane cross sections with a separate track bed in the middle of the road have the highest accident cost rate. A disproportionately high number of accidents on separate track beds are primarily caused by pedestrians. The majority of streetcar accidents involving injury (86 percent) occur at intersections and within the range of their direct influence, which is up to 50 meters. Serious accidents occur, in particular, at signal-controlled intersections (Figure 4) and on threeor four-lane roads with a separate streetcar track bed in the middle (Figure 5). Pedestrians are the main causers of these accidents in a particularly high number of cases. There is a higher risk of accidents associated with multi-lane road crosssections with a track bed in the middle of the road than with roadside or off-road track beds. Recommendations The key findings of the research project can be summarized as follows: When new infrastructure is built or existing infrastructure is altered or upgraded, a roadside track is to be preferred. Wherever there is sufficient space, off-road Figure 2: Killed and injured persons by type of road users Figure 3: Economic costs of different modes of transport by driving (left) and passenger (right) kilometers SCIENCE & RESEARCH Traffic safety International Transportation (70) 1 | 2018 32 track beds should be preferred. Only where this is not possible should a track in the middle of the road be considered. The areas around intersections, in particular, should then be very carefully planned with road safety in mind. At intersections, efforts must be made to make the streetcar track easy to notice, to provide enough pedestrian crossing facilities with safety features and signal control to allow motor vehicles to turn off the road. The intersection area and the space around it must be kept free of obstacles to visibility. Streetcars should have separate phases at signal-controlled intersections (thus preventing any conflicts with other vehicles, cyclists or pedestrians). On existing stretches of road, pedestrian crossings with safety features must be upgraded in locations where there is a need to cross, where there are significant flows of pedestrians or where significant numbers of crossingrelated critical situations or accidents occur. Safety audits [4] should always be carried out when new infrastructure is planned or when the existing infrastructure is being altered or upgraded. Audits are also recommended for existing infrastructure in order to identify and eliminate existing potential safety shortcomings, particularly at accident concentration points. The specific checklists developed during the project can be used for this. They can also help transport companies to analyze their accidents. Further improvements could be achieved through more research into both the automatic detection of conflict situations involving streetcars and the development of energy-absorbing front panels for streetcars. In addition, target group-specific and local campaigns should be developed to sensitize all road users, for example, for pedestrians to take care when they are crossing the road. ■ LITERATURE [1] DESTATIS (2010-2012). Federal Statistical Office, Verkehrsunfälle (Traffic accidents); Fachserie 8, Reihe 7, 2009-2011; Wiesbaden 2010-2012 (annual) [2] Brannolte, Griessbach, Plank-Wiedenbeck (2016). Maßnahmen zur Reduzierung von Unfällen mit Straßenbahnen (Measures designed to reduce streetcar accidents); commissioned by: Unfallforschung der Versicherer UDV; final report, Berlin 2016 [3] Ifeu (2013). Institut für Energie- und Umweltforschung Heidelberg GmbH, Transport Emission Model (TREMOD 2013), commissioned by: Umweltbundesamt (Federal Environment Agency) Version 5.3 (2012) as at: 19.06.2013 (Gohlisch, G., Umweltbundesamt, Fachgebiet 3.1 Umwelt und Verkehr (Environment and transport), unpublished [4] FGSV (2002). German Road and Transport Research Association (FGSV), Empfehlungen für das Sicherheitsaudit von Straßen (Recommendations for road safety audits, ESAS), FGSV-Nr.: 288, Köln 2002 Jörg Ortlepp Head Traffic Infrastructure , German Insurers Accident Research, Berlin (DE) j.ortlepp@gdv.de Jean Emmanuel Bakaba, Dr.-Ing. Manager Traffic Infrastructure, German Insurers Accident Research, Berlin (DE) e.bakaba@gdv.de Figure 4: Average accident costs of different intersection types Figure 5: Average accident costs of different types of cross-section