The PMMUS – Lisbon Metropolitan Area Sustainable Urban Mobility Plan – aims to improve accessibility in metropolitan areas by promoting sustainable and efficient mobility for people and goods, whilst stimulating economic development across the 14 municipalities in the metropolitan area. Its development, with targets for 2030 and 2035, follows the regional territorial development strategy in the pursuit of sustainability.

The Strategic Environmental Assessment Study (2024–2025) comprises four main stages: 1) Scope Definition, which sets out the assessment criteria; 2) Environmental Report, which analyses the proposals by considering the critical decision factors (CDFs), defining, comparing and evaluating the strategic alternatives and options under consideration; 3) Environmental Statement, which reports on the decisions taken; and 4) Follow-up and Monitoring, an ongoing phase involving monitoring and management.

The Strategic Environmental Assessment work involves connecting the plan’s objectives to other relevant plans and programmes, characterising affected environmental aspects, identifying significant effects, and considering sustainability recommendations. It also includes developing alternatives and establishing methods for monitoring, governance, and management to ensure environmental integration. Emphasising these aspects encourages stakeholders to feel committed and confident in the plan’s long-term sustainability.