It is prohibited to change lanes.

A prohibitory line is a solid, continuous line that separates lanes. Prohibitory lines may divide lanes of traffic that are going in the same direction (white lines) or opposite directions (yellow lines).

In the regulations concerning traffic signs, it is stated that it is prohibited to drive on or over a prohibitory line. This also means that it is prohibited to change lanes. If you are already in the left-hand lane when approaching an area with a white prohibitory line, you are of course allowed to continue driving in that lane.

A white prohibitory line looks like this: