<map lat='51.19440618353519' lng='6.403827667236328' zoom='13' view='0' float='right' />
When heading north or south, the best place is probably the onramp "Nordpark/West" at the A61. You can easily get there by bus. Just take number 013 or 023 to "Vorster Straße". From there it's just 5 minutes walking.
There is usually quite a lot traffic and enough space for cars to stop.