Spring may be around the corner, but in Estonia residents of one tiny island are celebrating the cold with the opening of a 12-kilometre (seven-mile) ice highway over the Baltic Sea that is one of Europe's longest.

"We wait for ice roads every winter because the frozen sea makes our lives much easier," Heldy Polluste, whose husband made the drive from Kihnu island to the mainland over the weekend, told AFP Monday.

The Estonian Road Administration greenlighted the road amid a deep freeze last week, bringing relief to the island's 500 residents, for whom the exotic commute is five times faster than taking the ferry.

Transport officials open the temporary motorways when the ice thickens to at least 25 centimetres (10 inches), though some residents choose to hit the road at their own risk even earlier.

A total of three frozen highways were deemed safe this year in Estonia, which in 2011 opened what local officials claim is the longest ice road in Europe.

But the 26-kilometre stretch linking the mainland port of Rohukula with Hiiumaa Island will remain closed this year "because the ice isn't thick enough in that part of the sea", traffic official Hannes Vaidla told AFP Monday.

To maximise safety, cars are only allowed on the frozen highway every two minutes and drivers must move slowly but steadily, without stopping, in order to minimise the risk of cracking the ice.

For once, passengers are also told not to wear their seat belts, to better be able to flee the car should the ice crack.

A Baltic nation of 1.3 million people, Estonia joined both the European Union and NATO in 2004.