Keilaniemi interchange improvements and Länsiväylä bridge works

Ring Road I and Länsiväylä are among the most important transport routes in the Helsinki capital region, which link the West Harbour and the motorways that lead to the capital region. The objective of this project is to improve the reliability and safety of the transport system on a vital Ring Road and to support the development of Keilaniemi.

This project includes the construction of new ramps at the southern exit of the Ring Road I tunnel, which will create a direct connection from Keilaniemi to Länsiväylä, in both the Helsinki and Hanko directions. The renovation will cover the current ramps to and from Ring Road I, as well as their bridges, on Länsiväylä in the Helsinki direction.

It also includes a complete rebuild of Tapiolansilta and the renovation of eight bridges on Länsiväylä. The bridge works ensure safety and extend the service life of the bridges.

Background

Keilaniemi is an area that has been developing faster than expected in recent years. The metro station, the Ring Road I tunnel, and the terminus of the number 15 light rail line have made the district significantly more attractive. Significant new construction is underway and being planned in the area.

Due to the developments in the area, a need for new ramps on the south side has emerged, which would allow for a direct connection from Keilaniemi to Länsiväylä, in both the Helsinki and Hanko directions. Currently, the route from Keilaniemi to Länsiväylä takes the long way through the Otasolmu roundabout in the north, which has limited capacity.

The south end ramps for the Keilaniemi tunnel were included in the 2015 traffic plan. However, they were not built with the tunnel, which was completed in 2019, as the strict traffic-based need for them had not yet emerged.

Interchange improvements and bridge works combined into one project

Now, the Länsiväylä bridges have reached renovation age, and Tapiolansilta is at the end of its service life. As the bridge works and the improvements to the Keilaniemi interchange will take place concurrently, they have been combined into one project. This allows for cost-effective construction and a reduction of the overall inconvenience.

The project is a joint effort of the Finnish Transport Infrastructure Agency, the City of Espoo, the Economic Development Centre of Uusimaa and Fintraffic. As a rule, the City of Espoo is liable for the Keilaniemi interchange and Tapiolansilta rebuilding costs, and the Economic Development Centre for Uusimaa is liable for the Länsiväylä bridge renovation costs. Fintraffic is responsible for the day-to-day operation of the Keilaniemi tunnel and its technical systems, which will also see some changes during the project.

Competitive tenders took place in June–September 2026. Construction work will begin in October 2026. Estimated completion is in November 2028.

The estimated cost of the project is EUR 30 million.

More information and the latest updates on the project are available on the website of the Finnish Transport Infrastructure Agency(external link, opens in a new window) (in Finnish). You can also subscribe to the project newsletter(external link, opens in a new window) (in Finnish).

The construction work will require temporary traffic arrangements. Information about these arrangements will be provided through the Finnish Transport Infrastructure Agency’s communication channels.