Introduction. The main environmental risks posed by roads are population depletion (deaths on roads) and barrier effects (habitat fragmentation). Barrier effects - animals avoid crossing roads, which leads to a decrease in the size and quality of habitat, optimal population size, reduced ability to find food and partner, increased genetic structuring and local extinction (Forman et al. 2003; Andrews et al. 2015; van der Ree et al. 2015). These risks against the background of other stressors, in particular the presence of invasive species, pollution, pesticide use, climate change, plant and animal diseases, may threaten the survival of populations.
This issue is especially relevant for herpetofauna due to their biological characteristics. In particular, reptiles and amphibians move slowly, are too small (for drivers to see), do not avoid roads, and in cold periods roads attract amphibians (thermoregulation) because the coating absorbs and retains heat (Case and Fisher 2001; Jochimsen et al. 2004).
The principle of ensuring ecological continuity is to identify priority efforts to mitigate environmental risks for animals and reduce the negative impact of the transport complex as a spatial barrier and source of pollution by introducing a number of technical means (eco-crossings, screens, embankments, landscaping). As it is not possible to change the environmental risks on all roads and for all species at present, it is necessary to identify the most vulnerable species, assess the risks to populations and the need for mitigation based on analysis of road density and traffic intensity.
Problem Statement. With the advent of land transport there was a progressive environmental problem - the transformation of landscapes, it first appeared in countries with developed road infrastructure in Western Europe and the United States, and quickly spread around the globe (Ellenberg, et al., 1981; Fetisov, 1999; Zagorodnyuk, 2006, Ilyukh, Khokhlov, 2012). Numerous publications by both foreign and domestic authors are devoted to the study of the impact of transport infrastructure. Special attention of European authors is paid to the study of the phenomenon of fragmentation of natural ecosystems. In Europe, there is a network of experts and institutions of IENE, which is studying the possibility of implementing preventive measures for landscape fragmentation, promotes the development of transport infrastructure in accordance with environmental requirements, by creating a safe, environmentally sustainable European transport infrastructure.
The ecological trail of the road network significantly exceeds its length (Vozniuk, 2014). This is due to the effects of, in particular, mortality on the roads of mammals, reptiles, reptiles (Forman et al. 2003), landscape fragmentation (roads divide the area into isolated areas, with low populations (sometimes below the minimum), so such populations lose genetic diversity and may become extinct locally), the loss of habitats of species and a decrease in the level of connectivity. In addition to these obvious effects, noise and vibration pollution are added, which inhibit the ability of reptiles, birds and mammals to detect prey or avoid predators (Forman et al. 2003), disturbed light regime (Rich and Longcore 2006). Roads contribute to the development of soil erosion processes, the spread of invasive and introduced species (300-800 seeds/m2 per year are transported to roadside ecotones by vehicles (Von der Lippe and Kowarik 2007), which contributes to the formation of local pseudo-populations), create obstacles and sources. (Forman et al. 2003).
Purpose. Substantiation of the principle of ecological continuity regarding the negative impact of transport infrastructure on natural ecosystems and search for possible ways to minimize and prevent such impact.
Materials and methods. The main research methods are the application of theoretical general scientific approaches to study: analysis and synthesis of international and domestic scientific and theoretical works, EU documentation (charters, design requirements), Ukrainian legal framework, literature sources; collection and analysis of statistical data to identify the dangers of the impact of road infrastructure on biodiversity and determine the value of the natural landscape.
Results. The result is an analysis of the scientific literature on the negative impact of transport infrastructure on animals, systematization of the main impacts for the preparation of methodological documents for organizations planning and designing transport infrastructure in Ukraine to reduce the negative impact.
Conclusions. The principle of ensuring ecological continuity is to minimize the negative consequences for the environment. In particular, by leveling the spatial barrier of the public highway. When laying a road through natural ecosystems, it is necessary to build transitions and passages for animals. In this case, their density and type must correspond to the natural rank of the territory. The construction of crossings for animals should be mandatory for all types of roads that cross ecological corridors. This is especially true for smaller roads, completely devoid of any transitions for animals, noise shields (on such roads are more likely to hit animals). An important point is the need to plan preventive methods at the planning stage of road construction. The analysis of the European experience shows that the negative impact of transport infrastructure on biota can be solved by consolidating the efforts of road transport specialists and specialists in the field of nature protection.
