The Grugatrasse starts in Essen-Steele and leads from there on paved pedestrian / bike path, which mostly leads over an old railway line, in the direction of Essen center. The bike path takes you directly to Gruga, Essen's famous park with exhibition hall. From there you are super fast right in the center. If you follow the path, it will take you to the new RS1 Radschnellweg.
The total of nearly twelve kilometers long way is nice to drive, is only due to its course usually pretty crowded. Especially on the center-close section, he is often heavily frequented, there is also one or the other bottleneck. Still, a very nice inner-city bike lane that largely lets you forget that you're cycling right through a big city.