Telraam is a citizen science service provider enabling private citizens to generate traffic counting data using a low-cost IoT sensor and open-source software. We maintain and develop the Telraam-sensor and platform where all data is published as open data. Telraam is the brainchild of Transport & Mobility Leuven (TML), a transport policy research company, Mobiel 21 (M21), an NGO with focus on citizen engagement and Waanz.in, a digital studio. The original project started in 2019 as a collaboration between TML, M21 and Waanz.in. As of January 2021, the development and maintenance of Telraam is managed by a new joint venture: Rear Window.