Search

Traflic safety and accessibility have been two important subjects in transportation research. On the one hand traffic crashes bring about high societal costs and serious health risks for urban road users. The cost oftraffic crashes is estimated to be 17 billion euros per year only in the Netherlands while over 600 people were killed in traffic, of whom 229 were cyclists and 195 were car users [l, 2]. Accessibility, on the other band, is regarded as one of the indicators of the quality of the transport system serving the public. There is comprehensive literature investigating the relationship between traffic crashes and factors associated with traffic, roadway design, built environment, and human factors. Similarly, several studies assessed and evaluated accessibility levels of individuals, communities, and regions by utilizing the aforementioned. factors. Nevertheless, there is a scarcity ofliterature investigating the relationships between accessibility and traffic safety. This is especially surprising considering that both subjects are associated with a similar set of factors, including land use and transport systems, as weil as individual and temporal factors [3-7]. The relationships between accessibility and traffic safety can be an adverse one; for example, improved accessibility by increasing the travel speeds (i.e., declining travel time) intensifies the crash risks which also deteriorates equity. Furthermore, levels ofboth accessibility and traffic safety are not homogeneous throughout urban areas and among different population groups. Based on the literature, it is obvious that accessibility is associated with economic equity [8]. lt is revealed that accessibility of lower-income groups is substantially worse than the higher-income groups as these groups have less mobility [9]. Previous studies also showed. that lower-income groups usually suffer from traffic safety problems more than other socio-economic groups [10-12]. Therefore, this research aims to add

While cycling is promoted as a sustainable and healthy mode of transport in many eitles in the Global North [1, 2], there are increasing concerns about the safety of cyclists. The increasing bicycle use in urban areas leads to a more intensely used cycling network, resulting in safety risks for cyclists [3]. Since 2010, the number of bicycle fatalities stagnated and the number of severely injured cyclists increased by 28% until 2018 in the European Union [4]. lt is therefore necessary to examine how bicycle use and motorized vehicle use in cities affects the nunber of bicycle crashes. To investigate this, the effect of the network-wide hourly exposure to cyclists and motorized vehicles on bicycle crash frequency is examined. That is, the total number of cyclists and motorized vehicles in the whole road network for each hour of the week were estimated and used as the network-wide hourly exposure. This approach allowed us to capture safety impacts of temporal variation in the numbers of cyclists and motorized vehicles in the same network more accurately. lt is a different approach compared to most bicycle safety studies, which often only use the daily average of bicycle and motorized vehicle volumes. The work presented here is based on our publication in Safety Science [5].

Cycling safety policy and research have mostly focused on cycling infrastructure, cyclists' behavior, and safety equipment in the past decades. However, the role ofbuilt environment characteristics (BECs) in the safety of cyclists has not yet been fully examined. For the Netherlands, this is rather surprising given the significant modal share of bicycles in daily trips, the importance attributed to urban spatial planning, and it being one of the most planned countries in the world. Despite the considerable improvements that have ta1cen place in traffic safety over the decades, the ( actual) number of cyclist deaths between 2011 and 2020 increased by on average 2% per year; the cyclists bad a major portion oftraffic death (followed by passenger cars); also, almost onethird of traffic death happened in built-up a.reas (about 25% of fatalities occurred on 50km/h roads in urban areas) in this period. Considering the aim of construction of on average 75,000 new homes per year until 2025, as weil as promoting bicycle use in as a healthy and sustainable mode of transport in the N etherlands, underst.anding the relationships between the BECs and cycling safety is invaluable for improving the safety of cyclists.

Our mobility system is changing rapidly. We are at the crossroad of major changes in the way we travel and deliver goods. Research agendas are adapting to this changed environment with new challenges and opportunities. This paper presents a research agenda for the future of transportation research structured along eight cluster topics of the Network on European Communication and Transport Activities Research (NECTAR). The research agenda firstly highlights the growing complexity and need for multi- and interdisciplinary transportation research. Secondly, sustainability needs to be addressed in transportation research in its full meaning, including relationships between policy-making investigations and environmental and equity effects. Thirdly, ICTs and digitalisation, the development of (shared) autonomous vehicles and shared mobility will have profound impacts on economies and spatial interactions all-around the world, and availability of high resolution spatial and transportation data. Digitalisation generates many new research opportunities but also give rise to new concerns about privacy, safety, equity and public health.