The busiest point on Highway 3 is in Helsinki, north of the Ring I junction, where the average traffic volume is about 90,000 vehicles per day.

[2] The route of the road is: Helsinki – Vantaa – Nurmijärvi – Hyvinkää – Riihimäki – Janakkala – Hämeenlinna – Hattula – Kalvola – Valkeakoski – Akaa – Valkeakoski (again) – Lempäälä – Tampere – Pirkkala – Nokia – Tampere (again) – Ylöjärvi – Hämeenkyrö – Ikaalinen – Parkano – Jalasjärvi – Kurikka – Ilmajoki – Isokyrö – Laihia – Korsholm – Vaasa.

In the Greater Helsinki, the road is also called Hämeenlinnanväylä, sometimes in colloquial language also Tampereenväylä.

Today, the road runs for about 200 meters in a tunnel, when the Goodman Shopping Center [fi] in Hämeenlinna was completed in 2014 on the pavement.

Some of the bridges at Highway 3 can be considered almost works of art and the rock cuts have been illuminated.

Ekku Peltomäki's light art work Lux Tavastia is next to Akaa's Terisjärvi.