Spring thawing occurs when a roads top layer melts while the bottom part is frozen due to soil frost. The frozen layer blocks water from draining and the roads stability is decreased.

Affected roads are then damaged or demolished by, amongst others, heavy lumber trucks. Today the Swedish road administration degrades or closes public roads with decreased stability. This is a financial heavy arrangement especially for the lumber industry, which gets disconnected from their products and thereby their main income.

Today spring frost costs the lumber industry about 510-590 million SEK per year. The main part of these costs is spent on increasing stock sizes. The cost will increase to about 650 million SEK per year due to larger quantities of lumber and an increased use of bio-fuel.