What are the rules regarding commuters boarding Singapore public buses with a personal mobility device (PMD) or bicycle?

1. PMDs and bicycles are strictly prohibited on public buses at all times
2. They are allowed only if the device is folded, clean, does not exceed 120cm x 70cm x 40cm, and does not block aisles or doors
3. Passengers must pay an additional fare to bring a folded PMD
4. They are allowed even if fully unfolded as long as it is not peak hour