The KNMI weather bureau issued a code red weather alert for the northern Dutch provinces on Tuesday morning as black ice created treacherous conditions on the roads.

Train and bus services have been reduced, schools are closed, Groningen University will be shut until midday at least and some  hospitals have cancelled all appointments. Court hearings have also been cancelled.

There have been accidents involving cars and lorries on several motorways and main roads but no serious injuries, news agency ANP says.

Salt

Gritting lorries are out in force and over one million kilos of gritting salt has been used to try to keep the ice at bay, a transport ministry spokesman told broadcaster Nos.

‘Freezing rain and black ice are the most difficult forms of winter precipitation to combat,’ transport ministry spokeswoman Debby van Slegtenhorst told the broadcaster. ‘It is more sensible to remain at home.

There are fewer trains running from Zwolle to Leeuwarden and Groningen, and Qbuzz has scrapped its regional services in Groningen and Drenthe.

Unusual

Nos weather forecaster Gerrit Hiemstra said it is extremely unusual for freezing rain and black ice to continue all night and into the morning. Although conditions will improve during the day, the black ice is likely to return on Tuesday evening, he said.

The ice layer is up to five centimetres thick in places, Nos says.

The code red alert applies in Groningen, Friesland and Drenthe. Code red means the weather conditions are so extreme they are likely to cause severe disruption. There is a  code orange alert in Flevoland, Overijssel and on the Wadden Sea islands.

Black ice is created when rain falls on a road surface which is below zero degrees. It is highly transparent and difficult to see compared with snow or sleet.

Photographs via RTL news