Railway company ProRail said on Tuesday it is to survey all trees growing along railway lines in an effort to reduce problems caused by falling branches.

The state-owned company is to carry out a survey of all 7,000 kilometres of railway track in the Netherlands to analyse the risks. There are an average of 150 to 200 trees in a radius of 30 metres from the track, and that means over one million trees will have to be mapped.

Problems with falling branches cause disruption to railway services on a weekly basis, and cause major problems once a month. Removing branches from the tracks takes between two six hours per incident, depending on the damage, ProRail said.

By law, no tree should be closer than 11 metres from a railway track and ‘in principle’ all trees within the forbidden zone should be cut down.

But that is not ‘socially acceptable’ and so only trees which are ‘really too close’ to the tracks will be removed, ProRail said.