Client: City of Tallinn, with Tallinn Airport and Mainor Ülemiste
Location: Ülemiste district, Tallinn, Estonia
Year: 2020–2021
Sector: Mobility · Agent-Based Modelling · Scenario Planning · Public Procurement
As Rail Baltica prepares to double the size of Tallinn’s airport-adjacent business district, this study modelled exactly when its roads and transit would hit capacity — and showed that widening roads would make things worse, not better.
Ülemiste — home to Tallinn Airport, the future Rail Baltica terminal, and the Ülemiste City business district — is expected to roughly double in size as high-speed rail arrives. Before approving further development, the city needed to know: at what point does current road and transit capacity actually run out, and what happens if we invest in the wrong things?
Won through public procurement, jointly financed by the City of Tallinn, Tallinn Airport, and district developer Mainor Ülemiste. Delivered with partners Ramboll Finland and Raul Kalvo/Inphysica, running from a 2019 bid through final delivery in 2021.
Combined a roughly 800-respondent employee survey on commuting behaviour with traffic counts, tram occupancy data, and mobile positioning data, modelled through agent-based simulation (GAMA) and GIS accessibility analysis. Five growth scenarios were tested — from road-expansion-led to active-mobility-and-transit-priority — each projected forward across multiple development stages.
Delivered as a full Estonian report with English executive summary, technical annexes, and a final presentation, alongside a “star plan” spatial concept for five development corridors radiating from Ülemiste.
- 73% of airport passengers currently arrive by car — despite Tallinn’s overall modal split being relatively balanced, the wider region driving into Ülemiste is heavily car-dependent.
- 95% of current drivers said they’d switch mobility mode if conditions improved — a striking latent demand for better transit and cycling infrastructure, from an 800-person employee survey.
- Road-widening scenarios were projected to increase car mode share, not reduce it — from 53% to 58% under a road-expansion scenario, due to induced demand — versus falling to 20–30% under transit- and active-mobility-priority scenarios.
- Both road and tram capacity are already near their limits at peak hours, meaning the choice of what to invest in next directly determines how much new development the district can sustainably absorb.
- The incoming Rail Baltica line was flagged as a physical barrier risk — the study explicitly recommends pedestrian underpasses and crossings so the new railway doesn’t cut Ülemiste off from the rest of the city.
Gave the City of Tallinn, the airport, and the district’s developer a shared, scenario-tested basis for transport investment decisions — directly linking transport choices to how much new floor area the district could sustainably support.