Measuring capacity, costs and alternatives along the Tarragona–Sant Vicenç corridor

In a study commissioned by Plataforma Mercaderies per l’Interior and PIMEC, MCRIT applied a cost-benefit methodology to assess the socioeconomic impact of saturation along the Mediterranean Corridor’s most congested stretch, and to evaluate the feasibility of alternative routing solutions. The study combined demand projections, infrastructure costing, externality valuation and economic activity modelling to compare three scenarios: continuing with the existing third rail (3r fil), the Ministry’s proposed inland diversion, and the Platform’s own alternative alignment.

The Tarragona–Sant Vicenç de Calders section, approximately 25 kilometres long, currently operates at 85% of its theoretical capacity of 200 trains per day, with around 170 daily circulations in 2023. Freight and passenger services share a triple-gauge track running immediately alongside residential areas and schools, creating what the TRANSCAT emergency plan classifies as a very high risk level.

Figure: Daily circulations along the Tarragona–Sant Vicenç corridor (2023), showing the bottleneck section in black at 170 trains/day by MCRIT (WB, 2025)

Saturation as a structural constraint

The study’s demand projections show that the third rail option is not a viable long-term solution. Even in the minimum growth scenario, total daily circulations would reach 224, exceeding the line’s theoretical capacity and pushing occupancy to 112%. Under higher freight modal share scenarios, between 720 and 1,560 additional lorries per day would shift onto the AP-7 motorway, generating significant increases in road maintenance costs, congestion, accidents and emissions.

Methodology and cost-benefit framework

The analytical framework combined demand projections from sources including the Port of Tarragona, the Port of Barcelona and ADIF’s CIRTRA statistics, with a circulation and capacity tool that identified where thresholds would be breached. A full Cost-Benefit Analysis covered infrastructure investment (CAPEX), operational and maintenance costs (OPEX), externalities and economic activity effects. Externalities were valued using the European Commission’s Handbook on External Costs of Transport (2019), with total road freight costs estimated at €0.1175 per tonne-kilometre compared to just €0.0110 for rail.

Infrastructure costs and economic returns

The Platform’s alternative involves a new dedicated freight line bypassing the coastal corridor, at a total investment of approximately €812 million across two phases. The Ministry’s alternative follows a different Phase 1 alignment at a total cost of around €928 million. Both alternatives generate strong cost-benefit returns, with IRRs ranging from 108% to 148% for the Platform option and 97% to 133% for the Ministry alignment, with an investment payback period of just five years in all scenarios. By contrast, the third rail generates rapidly escalating costs as freight overflows to road, with external costs alone rising to over €2 billion annually at 10% modal share.

The case for action

The Tarragona–Sant Vicenç corridor concentrates structural problems that make inaction increasingly costly. Dangerous goods trains run metres from homes and schools at a section already near its physical limits, while projected passenger growth will consume remaining capacity before freight growth is even factored in. Removing freight from the coastal corridor would also generate around €20 million per year in additional tourism revenue, as campsite operators estimate a 30% income uplift without freight traffic. The study demonstrates that both alternatives deliver returns far exceeding their investment costs, making the case for infrastructure planning that improves connectivity without perpetuating the safety, environmental and economic burdens the current alignment imposes on communities along this stretch of coastline.