Public participation is increasingly central to infrastructure planning in the Netherlands, evolving from consultation to integrated governance (Alpkokin, 2012; Bobbio, 2019). The Environmental Act, introduced in 2024, aims to simplify regulation, promote early stakeholder involvement, and enable local customization in spatial development (T. Kamer der Staten-Generaal, 2013a). By embedding participation into law, it seeks to improve decision-making quality, increase support, and reduce objections.

This shift reframes participation as a shared task between governments, contractors, and citizens. Contractors now operate within a governance model that emphasizes trust, flexibility, and societal value (Verweij et al., 2022). Their responsibilities in stakeholder engagement and environmental coordination are expanding, particularly during project realization. However, while early-phase participation has been widely studied, its role during the realization phase remains underexplored.
The main research question: How does the Environmental Act impact public participation during the realization phase of infrastructure projects, particularly for contractors?
To answer this, a qualitative design was used, combining a literature review, exploratory interviews, three case studies and an expert evaluation.

The findings show that the Act has not yet transformed participation during the realization phase. Participation remains largely procedural, focused on communication and compliance, with limited opportunities for stakeholder influence. Contractors often join after key decisions have been made, reinforcing an instrumental use of participation, more about risk management than co-creation.
While the contractor’s role is evolving, constraints such as late involvement, fixed contracts, limited resources, and unclear mandates hinder meaningful participation. Changes are mostly seen at the level of procedures and reporting (second-order governance), whereas deeper institutional shifts, trust, shared values, and clear role divisions (third-order governance) are lacking.
To bridge this gap, several improvements are needed: earlier contractor involvement, better role clarity, and flexible contract models that allow for participatory adaptation. Without such reforms, participation risks remaining symbolic. Contractors stepping into public roles must also embrace the societal value of participation—focusing not just on compliance, but on legitimacy, inclusiveness, and sustainability.
Limitations include the recent implementation of the Act, limiting observation to short-term expectations. The small number of cases reduces generalizability, and citizen perspectives are underrepresented. In addition, ambiguity in the definition of “participation” and variation in procurement practices create challenges in interpretation and execution.
In conclusion, the Environmental Act represents a symbolic but conditional shift. Its real potential depends on institutional alignment and a proactive, shared commitment to participation. For contractors, this means investing in stakeholder skills, integrating participation into planning, and engaging early with clients. Public authorities, in turn, must enable this by offering flexible procurement structures and clear accountability frameworks.
Future research should explore: long-term behavioural change, contractor adaptation, contract impacts on participation quality, and ways to reduce bureaucratisation without compromising participatory value.