The route runs southwest from Schotten in Vogelsbergkreis to Mainz-Kastel, a borough of the Hessian capital city of Wiesbaden.

The road continues through the Wetteraukreis, including the municipalities of Nidda, Wölfersheim, Friedberg and Rosbach vor der Höhe.

Route 455 merges with Bundesautobahn 5 (A-5) at the Friedberg exit and follows this autobahn to the Bad Homburg interchange.

These parts of the route were replaced by the A-5 and A-661 sections, and the original highway has now been downgraded to a state road (Landesstraße).

Bundesstraße 455 ends at the Rhine River at the Theodor Heuss Bridge in Mainz-Kastel, a borough of Wiesbaden.