From river to motorway
Until the 1930s the Woluwe wound openly through Diegem. When it was covered over in 1930-1935 it disappeared into an underground sewer. After the Second World War the roof of that sewer was asphalted and named the Woluwelaan. Where walkers once looked for peace and quiet, cars now raced past.
Around 1950 a first interchange was built for the Woluwelaan and the Leopold III-laan, the road to the airport. In the middle of the roundabout a piece of the old landscape survived until the end of 1975: a wide hollow with a lawn, in which the Woluwe split around a long, emerald-green islet.
The big interchange
In 1973 the old roundabout was demolished. Temporary viaducts were built, as well as a new railway bridge (1974) and new junctions with the Haachtsesteenweg and the Oude Haachtsesteenweg. Here too the Woluwe was covered over. Since then it has flowed beneath the huge new interchange, about 300 metres across, which opened in October 1976.
By around 1980 little was left of the old landscape. Brickworks, sand pits, housing estates, industrial zones and the expansion of the airport had cut the municipality into pieces. Diegem-Lo was squeezed between the airfield and the interchange, and the village centre lay in line with the western runway.