The road runs through the 3 Belgian regions (Brussels, Flanders and Wallonia) and the 3 communities (Dutch-speaking, French-speaking and German-speaking).

Starting at the small Brussels ring road crossroad Arts-Loi in the City of Brussels, the road is first named Rue de la Loi (direction Brussels centrum) or Rue Belliard (direction Aachen), then enters the Belliard tunnel under the Cinquantenaire park before it becomes the Avenue de Tervueren/Tervurenlaan past the Tervuren gate in Etterbeek.

It intersects the E40 highway again at Loncin and then runs through the city centre of Liège and crosses the river Meuse there.

R22 Woluwe-Saint-Lambert, Auderghem, Watermael-Boitsfort, Kraainem, Zaventem, Brussels Airport Brussels-capital Region / Flanders Flemish Brabant Flanders Flemish Brabant 22 (Bertem) E40 Brussels, Leuven, Liège, Genk (E314), Hasselt (E314) Bertem (10.258 inh.)

N264 Egenhoven, Brussels (E40), Genk (E314), Hasselt (E314) Dijle N251 Heverlee, Oud-Heverlee, Wavre (N25), Namur (N91) End of concurrency with R23 R23, Leuven ring road Leuven, Brussels, Tervuren, Wavre, Namur, Tienen, Diest, Aarschot, Mechelen N292 Leuven railway station, Diest N25 Haasrode, Oud-Heverlee, Wavre, Namur (N91) Liège Lovenjoel (2.206 inh.)

Liège R27 Sint-Truiden, Linter, Hoegaarden, Hannut, Charleroi, Namur Tienen (35.973 inh.)

N223 Vissenaken, Lubbeek, Tielt-Winge, Aarschot N29 Glabbeek, Bekkevoort, Diest Start of concurrency with N29 End of concurrency with N29 N29 Hoegaarden, Jodoigne, Charleroi R27 Hoegaarden, Hannut, Charleroi, Leuven, Namur Hakendover (1.385 inh.)

N784 Opheers, Veulen, Waremme, Borgloon Wallonia Liège Oreye (4.001 inh.)