I have been to Turku only once 10years ago, so I was surprised at the road tunnels we drived through on the Finnish national road 1 (Valtatie 1), (Motorway E18) from Helsinki. There are 7 double-bore road tunnels between Muurla and Lohja (Hepomäki, Lakiamäki, Tervakorpi, Pitkämäki, Orosmäki, Karnainen ja Lehmihaka).
Their combined lenght is 5,2km. The longest one - Karnainen Road Tunnel (Karnaisten tunneli) is 2,3km.
It's the longest road tunnel in Finland.
Tunnels' construction was completed in 2009.
Tunnels are equipped with the emergency exits and SOS-phones.
The road leading often between high rock walls
is nice and impressive.
The below picture comes from http://www.ykkostie.net/tunnelit.html
Here's LINK about other road tunnels in Finland, and below my photos of the tunnels:
It looks like Finns like the tunnels. Turun Sanomat newspaper from Turku published on 2.12.2012 project of Marco Casagrande (the picture below). The architect has vision of drilling tunnel under centre of Turku. He says "Lowering the road into a tunnel going under the Aura River would free the heart of Turku from cars for good. And Turku is worth it." (here's link to his blog, this post is in English). Reading comments on the internet I see that this project has many enthusiasts.
Times shows if this dream comes true ...