Various midsummer events could also see busy traffic on Friday evening. Heavy return traffic is expected on Sunday.
On Friday, an elderly man was seriously injured when his car skidded off the road at Kirkkonummi and hit a tree. He was taken to hospital.
On Thursday, accidents claimed two lives. At Mustasaari, one man was killed in a crash between a truck and a car. In another accident in Tyrnävä, one person was killed and two more were injured.
Police have stepped up patrols to deal with cases of speeding and drunken driving. The authorities are also keeping a watchful eye on lakes and waterways to combat alcohol abuse by boaters.
Drivers needing roadside assistance over the weekend can phone the Automobile and Touring Club of Finland at 0200 8080 (99 cents/minute + local charges). Boaters can call the association Search and Rescue at 0204 1000 for help. YLE24