By afternoon there was a queue 27 kilometres long heading into the Vaalimaa crossing point between Hamina and Vyborg.
Over the previous two weekends, the backup has been as much as 35 kilometres.
The problem is blamed on Russian border officials' inability to cope with growing volumes of lorry traffic. Despite much discussion involving Finnish and Russian authorities, the problem has been recurrent, especially on weekends.
No Help Yet from New Lots and Lane
An extra lane is being built for trucks waiting to cross at Vaalimaa, but construction has been delayed. It is expected to be ready in November, in time for the annual year-end traffic jams. However it is only about one and a half kilometres long, so is not likely to help much. And in the meantime, its construction is hampering traffic.
A new waiting lot was hastily constructed last winter, but it has not been used much. A new permanent parking lot designed to hold 1,000 lorries will not be ready for three years.
Vaalimaa is the southernmost and busiest crossing point on the Finnish-Russian border. So far this year more than 1.5 million people have passed through it.