Is a public vehicle permitted to drive on all the marked lanes?

1. No, it may only drive on bus lanes.
2. No, it may only drive on the right lane.
3. No, only on the left side of the road.
4. Correct answer: Yes, it may also drive on lanes that are not marked as bus lanes.

WhyPublic transport may drive in any lane, not only the bus lane. The bus lane is its right, not its duty.