What is the meaning of the following traffic sign?

1. 4-wheeled vehicles only are permitted to use the roadway or the lane.
2. Correct answer: Designated lane for trams, buses, taxis and vehicles that transport at least the number of passengers that is indicated in the sign.
3. All vehicles are permitted to use the roadway or the lane, except for trams and electric buses.
4. A lane prohibited for public transportation.

WhyThe sign with a tram, bus, taxi and a number of passengers marks a public transport lane. Vehicles carrying at least that many people, driver included, may also use it.