After Lisbon and Porto urban lines were opened to the possibility of sub‑concession, the mayor of Cascais has proposed that Cascais — together with Oeiras and Lisbon — take over management of the Cascais suburban line and make train journeys within the municipality free for residents, workers and students. The proposal reframes the sub‑concession debate as an opportunity for local control but raises practical questions about funding the revenue shortfall, coordinating services across municipalities, the legal and contractual steps required, and the potential impacts on ridership, local traffic and equity.