The damage to the Dutch economy caused by traffic jams reached up to €1.1bn last year, according to research commissioned by transport sector lobby groups.

In 2014, traffic congestion cost the economy between €655m and €852m, the report by the TNO institute said. Now the figure is back at the same level as in 2011, despite massive government expenditure on road widening and other schemes.

The biggest traffic blackspsots are on the A15, the A4 and on the A2, the organisations, which describe the rise as ‘alarming’, say.

MPs debate the infrastructure ministry’s budget for 2017 next week.