Divisive connections: Theory and tools for the quantification of barrier effects in transport infrastructure projects

Transport infrastructure increases regional accessibility but at the same time it creates barriers that reduce local accessibility. These barriers reduce social contacts between people, and limit access to services and leisure. Barriers make cycling and walking less attractive, which has negative impacts on health, and can lead to increased emissions from cars. Assessments of barrier effects are commonly based on general descriptions and rough estimations, although methods for the quantification of these effects have been developed. Reasons for not using these methods are: limited dissemination, difficulty in separating barrier effects from other effects, and differences in the terminology that is used to describe them. This thesis aims to make existing academic knowledge and tools regarding the quantification of barrier effects more applicable in practice. The thesis presents a conceptual model that defines five determinants of barrier effects: Transport features, Crossing facilities and street network, People’s abilities, Land use, and People’s needs, and defines three levels of barrier effects. Further, the thesis lists indicators and methods for quantifying barrier effects. The model and indicators are studied in two case studies. In the first, four of the indicators were operationalised in a transport infrastructure project using conventional GIS tools. In the second, the indicators were studied in an ongoing transport infrastructure project using an action research approach. In this study, participants reported how the barrier effects analyses contributed to the impact assessments with transparent and precise support, which allowed the stakeholders to solve a long-standing conflict about the localisation of the infrastructure. One of the central issues that was revealed is the need for collaboration in order to create input material for the analyses. Based on these results, the main finding of this thesis is that knowledge of both social and technical processes in the assessment of barrier effects is required for making existing academic knowledge and instruments more applicable in practice

The wrong side of the tracks: quantifying barrier effects of transport infrastructure on local accessibility

Cities can be characterized as distributions of accessibility. Two elements in the urban fabric that influence this distribution of accessibility are motorways and railways. These are powerful connectors in urban traffic systems but can also create strong barriers on a local scale. Based on a literature review, the negative effects of these barriers-also called severance-on social inclusion, health, and access to workplaces are described. Furthermore, it is pointed out that barrier effects are determined by three elements: transport infrastructure, built environment and people\u27s wishes and needs. Two morphological indicators are presented with which some of the barrier effects identified in the literature review can be quantified. One indicator is related to proximity to facilities, measured by network distance. The other relates to accessible offer of facilities, measured as the number of facilities within a given metric radius from each residential address. The indicators are demonstrated in a case study in Gothenburg, Sweden, where a four-lane motorway and railway tracks form substantial restrictions on the urban development of a former harbor area in the center of the city. In the case study the consequences of placing the infrastructure in tunnels is assessed. The analyses show how the increases in proximity to facilities and in accessible offer of facilities are spatially distributed in non-linear patterns. These results demonstrate the importance of taking into account transport infrastructure, built environment and people\u27s wishes and needs when assessing barrier effects. The case study indicates the potential of the proposed indicators for inclusion in a method for the quantification of barrier effects

The insects of the Winterswijk Muschelkalk

This article describes the insect fossils found in the Muschelkalk of Winterswijk. Amongst these finds is a beetle elytron, which constitutes the oldest known beetle fossil from the Netherlands. The other insect fossils from the Muschelkalk of Winterswijk that are also briefly discussed, include a dragonfly wing fragment and a complete cockroach wing. These finds make Winterswijk unique amongst Muschelkalk outcrops, no other Muschelkalk site has yielded so many insect fossils. These insect fossils also help us to better reconstruct the depositional environment at Winterswijk: these fi nds indicate more terrestrial influx in the top section of the Winterswijk quarry

Evolutionary rescue theory, antibiotic resistance and the details of bacterial infection

When a population faces a novel (stressful) environment this may cause the population to decline. In such situations evolutionary rescue theoryaims to predict the probability that a population adapts to the new environment (rescue), instead of facing the otherwise inevitable extinction. Thus, evolutionary rescue theory has the potential to help us understand when to expect the evolution of antibiotic resistance in bacterial populations. Yet, current models of evolutionary rescue fail to account for the mechanisms deployed by bacteria to cope with stressful conditions (like the presence of antibiotics). Here we examine two such mechanisms using stochastic modelling. First we examine the effect of biofilm formation, which occurs in the majority of bacterial infections. Biofilms have an explicit spatial structure, whilst standard evolutionary rescue theory assumes well-mixed populations. Secondly we examine the influence of persistercells, these are dormant cells that tolerate antibiotics exposure, which are also not modeled in standard evolutionary rescue theory

The social dimension of barrier effects of transport infrastructure

Motorways and railways increase regional accessibility but can at the same time reduce local accessibility by creating barriers in pedestrian and bicycle networks. This can influence several SDGs, such as SDG 5 (gender equality), 10 (reduced inequalities), and 11 (sustainable cities and communities). This paper presents some first principles of how quantitative indicators of direct barrier effects can be adapted in order to address specific social groups. To demonstrate this, the indicator \u27Choice\u27, from a set of four indicators previously developed, was adapted to assess accessibility by children to parks, and waterside and leisure facilities. The indicator was applied to a case in Gothenburg, Sweden, where a GIS-based analysis measured changes in barrier effects brought about by hypothetically placing an existing motorway and railway in tunnels. The results demonstrate how such local accessibility indicators can be adapted to make them relevant for impact assessments of infrastructure projects, and thus enable the measurement of compliance with social sustainability targets in transportation infrastructure planning