Applied Road and Rail Ecology

TRIEKOL – Applied Road and Rail Ecology


Vad är TRIEKOL? / What is TRIEKOL?
TRIEKOL är Trafikverkets forskningsprogram om transportinfrastrukturens inverkan på biologisk mångfald och landskapsekologi.

TRIEKOL is the research program of the Swedish Transport Administration (STA) on the impact of transport infrastructure on biodiversity and landscape ecology.

Syfte / Aim

Målet med forskningsprogrammet är att ta fram metoder och kunskap som transportsektorn behöver för att bibehålla, och om möjligt förbättra, ekologiska funktioner och kvalitéer i landskapet. Arbetet inom programmet har en direkt koppling till Trafikverkets pågående verksamhet och resultaten används för utveckling av nya riktlinjer, planering av nya investeringsprojekt och vid utveckling av drift och underhåll av befintliga vägar och järnvägar.

The aim of the research programme is to develop knowledge and methods that can help the transport sector to maintain and, where possible, improve the ecological functions and qualities of the landscape. The work within the program has a direct link with ongoing operations of STA, and the results are used to develop new guidelines, planning new investment projects and in the development of maintenance of existing roads and railways.

Programperioder / Program periods

TRIEKOL påbörjar 2024 en ny programperiod, vilken omfattar ett antal forskningsprojekt som just nu är under uppstart. Tidigare programperioder TRIEKOL I-III har omfattat åren 2009-2023 (se mer om resultaten från period I och II och från period III).

Hösten 2021 startade TRIIAS: tillämpad forskning om bekämpning av invasiva växter i infrastruktur. TRIIAS är en fristående del av TRIEKOL som pågår fram till år 2025 (se mer om TRIIAS).

TRIEKOL is starting a new program period in 2024, which includes a number of research projects currently in start-up. Earlier program periods TRIEKOL I-III included the years 2009-2023 (see more about the results of period I and II and of period III).

The autumn of 2021 was the start of TRIIAS: applied research on management of invasive plants in infrastructure. TRIIAS is an independent part of TRIEKOL, running through 2025 (see more about TRIIAS).

Språk / Language

Hemsidan är tillgänglig på både svenska och engelska, du kan byta språk när du ser en flagga som denna och via huvudmenyn.

This website is available in both English and Swedish, you can switch language when you see a flag as this one and in the main menu. 


Prenumerera på nyheter

Ta del av nyheter från TRIEKOL:s forskning via e-postlistan för svenska IENE-nätverket.

Ongoing TRIEKOL III research

Wildlife adaptation of existing bridges

In this subproject we monitor and compare wildlife's use of existing bridges before and after wildlife adaptation. 

Level crossings and wildlife warning systems

In this subproject we monitor level crossings in terms of wildlife use and connectivity between roadsides, and the effect on wildlife accidents and driver behaviour.

Over- and underpasses for larger wildlife

In this subproject we monitor wildlife’s use of over- and underpasses and compare performance depending on different parameters.

Modeling of permeability and mortality effects on wildlife populations

In this subproject we apply a previously developed model to a real Swedish landscape, thereby validating the previous results. 

Effect of noise measures for birds

In this subproject we study the effects of noise mitigation along existing infrastructure near important bird habitats.

Amphibian passages

In this subproject we derived valuable results regarding effectiveness of amphibian mitigation measures in reducing roadkill and barrier effects.

Management and construction of road infrastructure habitats for biodiversity

In this subproject we analyse which environmental conditions that constitute ecological key factors for different biodiversity values in road infrastructure habitats.

Management and construction of rail infrastructure habitats for biodiversity

In this subproject we analyse which environmental conditions that constitute ecological key factors for different biodiversity values in railway infrastructure habitats.

Ecological functions of infrastructure habitats

In this subproject we use qualitatively identify different ecological functions of road and rail infrastructure habitats.

Passages for reindeer

In this subproject we study the reindeer’s use of existing bridges in Norrbotten, in dialogue with the Sami villages concerned. 

Wild boar and roads

In this subproject we study how wild boars move in relation to different types of roads and where mitigating measures could be motivated.

Earlier TRIEKOL work

Barrier effects and fragmentation

Roads and railways split the landscape and constitute barriers for many species. Traffic is an immediate danger for animals trying to cross the roadway, but the traffic barrier may also have more long-term ecological consequences for populations. This subproject studied theses effects and connections.

Noise in natural areas

Both humans and wildlife are negatively affected by traffic noise. So far, this problem is dealt with mainly in the built environment. But also in natural environments technical noise is a serious disturbance factor. This subproject studied how traffic noise effects in valuable natural habitats can be identified.

Infrastructure habitats

Habitats created or emerged in connection with roads, railroads and other man-made environments, can be important in species conservation work. Many of these habitat types are otherwise rare or declining in the landscape, for example managed grassland, ponds, bare soil and trees along roads. This subproject studied these habitats and their biodiversity in several ways.

Model of infrastructure impacts

In order to better understand the effect of transport infrastructure in the natural environment, TRIEKOL developed a conceptual model. The model describes the effects of transportation infrastructure on biodiversity in a pedagogical and transparent way. This subproject describes the development of this conceptual model.


Work with biodiversity in transportation infrastructure means acting in the middle of several very different worlds. The fields of transport infrastructure and conservation of natural and cultural environments have different aims, vocabulary and organisation. Cooperation is the key to success. This subproject describes how cooperation can lead to successful projects.

Infrastructure impacts on protected areas

Ecological impacts of roads and railways extend into the surrounding landscape, leading to habitat degradation and reduced wildlife densities within an area larger than the actual road or railway corridor. As a consequence, natural values within large areas may be jeopardized due to transport infrastructure. This subproject studied the effects of infrastructure on protected areas.

Other minor projects

Some minor projects of importance for the transport sector to maintain and improve the ecological functions and qualities of the landscape were conducted during TRIEKOLs program period II: the importance of the convention on biological diversity and the concept of exclusion habitats was studied.

Contact us

For inquiries concerning TRIEKOL program period I-III or TRIIAS program, please contact the TRIEKOL program directors.

The team

See the TRIEKOL and TRIIAS research team and contact persons at the Swedish Transport Administration.