Harbour tunnel’s plan proposal for decision-making

Passenger traffic between Tallinn and Helsinki is planned to be concentrated in the West Harbour, and the volume of port traffic is expected to increase from the current level. The intention with the planned harbour tunnel is to improve the flow of traffic and reduce its adverse effects in the environment of the West Harbour. The goal is that all of West Harbour’s goods traffic and a significant part of the port’s passenger car traffic will move underground in Jätkäsaari and Ruoholahti. The detailed plan proposal required by the tunnel will now enter political discussion.

The planned changes to the harbour’s passenger traffic would increase traffic volumes in the area by dozens of per cent by 2032. When the modernisation of the West Harbour is completed, approximately 4,000 passenger cars, 1,000 trucks and slightly less than 30,000 passengers will pass through it every day.  

The harbour’s truck traffic between the West Harbour and Länsiväylä is planned to be moved to the tunnel. Passenger cars entering and leaving the ship can also use the tunnel. The harbour tunnel will not only calm traffic on the island, but also improve traffic safety and air quality in the area.  

The harbour tunnel would significantly reduce harbour-related traffic in the city centre and make it possible to open the Eteläsatama area more extensively for the use of city residents. When the ships to Tallinn are moved to the West Harbour, only the ship traffic to Stockholm will remain at Katajanokka. This will reduce harbour-related traffic in the city centre by approximately 75%, because the traffic volumes of the Tallinn route are significantly higher than those of the Stockholm route. 

The construction of the tunnel is estimated to cost approximately EUR 300 million, and its costs are borne by the Port of Helsinki Ltd. 

Design work prior to the plan proposal

The Helsinki City Council made a decision-in-principle in February 2021 on the reorganisation of port operations and the starting points for the land use of the harbours areas in Eteläsatama, Katajanokka and Länsisatama. Based on the decision-in-principle, the Port prepared a development programme, which was approved by the City Board in early 2022. The harbour tunnel is the first stage of the development programme.

In June 2024, a location option was chosen as the basis for the planning, with the tunnel entrance located between the Ilmarinen building and Lapinlahti Park. The chosen option is the only one that can be implemented within the timeframe outlined by the City Council in 2021.

Lapinlahti Park’s natural values are taken into account

The tunnel construction site would have an impact on Lapinlahti Park. Two endangered species have been encountered in the park, and solutions have been found in the design to safeguard their living conditions.

In the flying squirrel’s key habitat, the tunnel will be built using the thin rock roof technique. This will minimise the amount of tunnel section opened from the top and save the habitat of the flying squirrel living in the area.

The living conditions of a small butterfly species, Depressaria chaerophylli, will be secured especially by sowing its food crop in new areas of the park. Planning is promoted in cooperation with the authorities and the effectiveness of the plans is monitored.

Noise impacts will remain low

The noise impacts of the tunnel will remain low and will not impair the recreational use of Lapinlahti Park.  decrease in traffic volumes on Länsisatamankatu and Tyynenmerenkatu will slightly reduce noise along the streets. The new noise barrier to be built on Länsiväylä will be dimensioned so that noise does not increase in Lauttasaari residential area.

The plan proposal available for comments

The Urban Environment Committee will discuss the plan on 11 February. After that, the plan proposal is available for statements and objections. The plan will be discussed by the City Board again in autumn 2025. The City Council will decide on the local detailed plan at the end of 2025.  

The plan proposal will be presented to residents in spring 2025. The location and date of the resident event will be announced later.