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Additional Information

Contact Information

The Finnish Transport Infrastructure Agency

Project Manager

Janne Wikström

  • 029 534 3600

The Finnish Transport Infrastructure Agency

Project Manager

Juha-Pekka Hämäläinen

  • 029 534 3563

Lahti Southern Ring Road

Road project Completed

The aim of the project is to ensure smoother and safer transport along the busy main road No 12 and to improve conditions for land use development and business throughout the Lahti region.

  • Planning
  • Year 2017 - building of part 2 begins
  • Year 2018 - building of part 1A and 1B begins
  • Completion

Basic information of the project

Destia, VALTARI-alliance, Suomen Maastorakentajat
275 000 000 €
Responsible parties
Finnish Transport Infrastructure Agency
  • Considerable improvement of traffic safety and flow
  • New opportunities for the economic life and from the perspective of land use
  • Comfort of living improves and the risk of groundwater contamination reduces

Lahti Southern Ring Road

Background to the project


The Lahti Southern Ring Road project involved rerouting main road No 12 to the south of Lahti and improving regional road No 167, which enters Lahti from the south.

The project consisted of two works sites and three separate contracts.

Subproject 1A involved widening the Lahti Southern Ring Road at the Hollola end to provide two lanes along main road No 12 between Soramäki and Okeroinen as well as building 17 bridges.

Subproject 1B covered the southern end of the Lahti Southern Ring Road. The works site began to the east of the Okeroinen interchange and ended at the Joutjärvi interchange. This was a technically challenging stretch of the road, and the project involved, among other works, building several interchanges as well as two tunnels. Read more about the plan from the Project plan for the development phase and Value for Money report published on May 29th, 2018.

Subproject 2 involved widening Uudenmaankatu to provide four lanes along regional road No 167, which enters Lahti from the south, between Renkomäki and Laune. The project also involved renovating underpasses and bridges.

Works along regional road No 167 began in the spring of 2017 and works along main road No 12 in the spring of 2018. The reopening of the main road No 12 to traffic took place in December 2020. Finishing works will took place in 2021, and final surfacing is scheduled for 2023.

Objectives of the project

Rerouting main road No 12 further south improved traffic safety and flow considerably, as it diverted traffic away from the centres of Lahti and Hollola. Comfort of living improved in residential areas once traffic was diverted elsewhere, and lower traffic volumes meant lower noise levels, emission levels and congestion in the surroundings of the old route of main road No 12. Safer and smoother traffic also improved the reliability of goods transport.

From the perspective of land use development, the Lahti Southern Ring Road provided new opportunities for developing the area around Lahti railway station, the former plot of the Asko furniture factory, the Sopenkorpi district and the centre of Hollola.

The bypass promoted the development of the Nostava logistics park and created efficient transport links to the Kujala and Lotila industrial parks.

Rerouting main road No 12 further south has also reduced the risk of groundwater contamination in the Salpausselkä area, which is an extremely important source of groundwater.

Cost of the project

The project's total cost was as estimated EUR 275 million. The investment in the Lahti Southern Ring Road amounted to EUR 258 million and the investment in regional road No 167 to EUR 17 million. The Finnish State share of the costs was 72% (EUR 198 million), and the remaining 28% (EUR 77 million) was split between the local authorities of Lahti and Hollola.