Picking up throughout the day, Midsummer return traffic bottled up in places late on Sunday afternoon.
Traffic jams are reported on Highway 5 around Kuortti, and on Highway 9 between Orivesi and Tampere as well as around Jämsä and Kouvola.
There was also congestion on Highway 4 between Heinola and Jyväskylä.
Drivers' patience was tested, as driving speeds have slowed down to an average of 20 to 30 kilometres per hour in the worst congested places.
Earlier it was estimated that return traffic would not be as heavy as outgoing traffic before the festive days due to many staying on for their summer holidays after Midsummer. However, the Finnish Transport Agency said that holidaymakers did not have a noticeable impact on the total volume of return traffic.
Travellers were, however, concentrated on certain parts of the highway network. Some stretches of road, such as between Mikkeli and Heinola, even suffered from worse congestion on Sunday than a few days earlier.
The roads were busier than usual until around midnight.