# Avoid zone category with exceptions

In case that permission is granted to access some zones in a category but not all of them, the route can be planned using avoidance of a zone category with some exceptions.

For example, there is a driving ban on a few streets for diesel vehicles including cars in Berlin. Suppose an owner of a diesel car is a resident in one of the affected areas, say Leipzigerstraße, which is on the list of diesel driving ban. A route for this driver needs to avoid all other DIESELFAHRVERBOT zones except Leipzigerstraße. This can be done by avoiding all environmental zones except BERLIN UMWELTZONE and LEIPZIGER STRASSE DIESELFAHRVERBOT.

The avoidance option in this case is avoid[zoneCategories]=environmental;exceptZoneIds=here:cm:envzone:2,here:cm:envzone:261.

The blue line in the above image shows the route that passes through Leipzigerstraße using the avoidance option with an exception, while the pale blue route is planned without exception.