Public participation is crucial for achieving ambitious societal goals, including housing expansion, emissions reduction, mobility accessibility, and climate resilience. However, satisfying diverse stakeholders becomes increasingly challenging as projects become more complex. The Environment and Planning Act (Omgevingswet) in the Netherlands aims to streamline permit processes and enhance collaboration among stakeholders, emphasising public participation. This research investigates how public participation processes are shaped following the implementation of the act, focusing on the Oude Lijn and the HOV4 case study. Through 13 semi-structured interviews and 10 observations, the study examines organisational aspects, such as participation planning, coordination, transparent communication, organisational choices, mindset, and perspectives. Various effects such as influence, expectations, understanding, trust, efficiency, and representativeness are analysed. Findings reveal nuanced relationships between participation processes and effects, providing valuable insights for professionals seeking to understand and optimise participation processes. Understanding these dynamics is crucial for achieving effective and inclusive public participation, ultimately contributing to more sustainable and resilient infrastructure and urban development projects.