Traffic jams stretched to 150 kilometres on the Brussels ring road and Flemish motorways on Friday afternoon.
The traffic is due to evening rush hour combined with the start of the construction holidays, the Flemish Community Holiday, and several accidents.
The Antwerp ring road is significantly busy in both directions, according to the Flemish Traffic Agency.
An accident occurred on the slip road connecting the E34 to the Antwerp ring road at Beveren, though there was less congestion overall on the motorway towards the sea.
Motorists faced significant delays on the outer Brussels ring road, particularly between Kraainem and Wemmel.
