Towards Insect-Friendly Road Lighting—A Transdisciplinary Multi-Stakeholder Approach Involving Citizen Scientists

SIMPLE SUMMARY: Road lighting is a service provided at night, mainly to ensure the secure and safe passage of humans. However, lighting at night can have adverse effects on insects or ecosystems, which are not yet considered in planning. Here, we introduce a comprehensive approach for the design and implementation of a novel insect-friendly road luminaire. The lighting design provides an optimized radiation geometry that avoids emissions at the trajectory height of insects, reduces the attraction of insects and the fragmentation of their habitats, and at the same time provides adequate night-time illumination in residential areas. The effects of the new design on insect behavior and night sky brightness will be evaluated two years before and two years after the change of the road luminaires and additionally in a direct comparison, as some luminaires of the old design will remain as controls. Citizen scientists are involved in the identification of insects and the measurement of night sky brightness. A broad public engagement program also highlights discussions about the competing interests of different stakeholders in lighting design, explicitly including the effects of illumination on insect fauna and biodiversity. ABSTRACT: (1) The project “Tatort Streetlight” implements an insect-friendly road light design in a four year before–after, control–impact (BACI) approach involving citizen scientists. It will broaden the stakeholder interests from solely anthropogenic perspectives to include the welfare of insects and ecosystems. Motivated by the detrimental impacts of road lighting systems on insects, the project aims to find solutions to reduce the insect attraction and habitat fragmentation resulting from roadway illumination. (2) The citizen science approach invites stakeholders to take part and join forces for the development of a sustainable and environmentally friendly road lighting solution. Here, we describe the project strategy, stakeholder participation and motivation, and how the effects of the alternative road luminaire and lighting design can be evaluated. (3) The study compares the changes in (a) insect behavior, (b) night sky brightness, and (c) stakeholder participation and awareness. For this purpose, different experimental areas and stakeholders in four communities in Germany are identified. (4) The project transfers knowledge of adverse effects of improperly managed road illumination and interacts with various stakeholders to develop a new road lighting system that will consider the well-being of street users, local residents, and insects.