Before the development of motorways the N4 was a main artery for traffic going south east from Brussels and it was dotted with many friteries, cafes and petrol stations.

From the 1960s to the end of the 1980s, it has been superseded by the completion of the A4 motorway which runs from Delta in Brussels down past Arlon where shortly after it enters Luxembourg where it becomes part of the Luxembourg by-pass system until it reaches the south of the city where it turns south continuing down to Thionville and Metz in France and onwards.

[citation needed] Outside of major towns the N4 mostly consists of dual carriageway with the opposing lanes separated by a central reservation or concrete blocks, but certain sections are still without any form of physical separation and have been the scene of many fatal accidents.

The N4 still offers a more pleasurable and scenic route to the south of Belgium for the less pressed driver and for bicyclists.

The end sections remain busy routes during the rush hour due to the high number of commuters travelling to and from Brussels and Luxembourg from residential communities all over the area.

Brussels-capital Region R20 Brussels inner ring road Namur Etterbeek (48.535 inh.)

Dyle N268 Basse-Wavre, Grez-Doiceau, Leuven N239 Wavre-Center, Walibi Belgium, Ottignies-Louvain-la-Neuve N243 Wavre-Center, Chaumont-Gistoux, Perwez 7 E411 Brussels, Namur, Arlon N25 Chaumont-Gistoux, Grez-Doiceau, Leuven Start of cocurrence with N25 Namur 8a (Louvain-la-Neuve) E411 Brussels, Wavre, Namur, Arlon N233 Louvain-la-Neuve-Centre, Ottignies Brussels End of cocurrence with N25 Corbais (1.351 inh.)

N91 Champion, Bouge, Éghezée, Leuven N90 Floreffe, Sambreville, Charleroi, Mons Start of cocurrency with N90 N80 Fernelmont, Hannut, Sint-Truiden N92 Wépion, Profondeville, Dinant Meuse N947 Jambes, Yvoir End of cocurrency with N90 N90 Andenne, Huy, Liège Erpent (2.823 inh.)

Luxembourg Aye, Humain N839 Liège, Rochefort, Hotton, Marloie N873 Marloie, Aye, Vivalia hospital N86, N63 Marche-en-Famenne, Rochefort, Hotton, Durbuy, Liège Marche-en-Famenne (17.758 inh.)