Program period III


Present program period

The research program TRIEKOL has its third program period between the years 2017 and 2022. 

Topical structure

The research in Triekol III is structured in a number of subprojects (see below). Each subproject is derived from a particular question of importance to preserve and enhance biodiversity when constructing and managing roads and railways in Sweden.

Despite linkages between some subprojects, they are intended to function as work packages, i.e. each producing scientific publication and recommendations that can be implemented in steering documents and guidelines of the Swedish Transport Agency (STA), and each with its given budget.

Subprojects will as far as possible make use of data available from previous and ongoing monitoring projects, and relate these to the international knowledge level. Some minor subprojects are focused on completing previous studies, where smaller additional research is expected to provide important knowledge. 

The projects are divided in two major parts: Animals, dealing with the impacts on vertebrate population such as wildlife accidents, barrier to movement and noise disturbance, and Infrastructure habitats, dealing with the biodiversity directly related to the vegetation, such as plants, insects and other invertebrates, and pollen/nectar resources.

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.


Program period III of TRIEKOL is funded by Trafikverket (STA). The research project is coordinated by SLU Swedish Biodiversity Centre, CBM.

The program group consists of a program manager and a deputy program manager, as well as project managers responsible for each sub-project. The staffing of the respective sub-projects involves researchers and staff from other universities, authorities and consulting firms. The program also has chosen representatives from the STA. 


For inquiries concerning TRIEKOL program period III, please contact the program directors here.