Urban greenery specialist GWS Living Art has installed green roofs on 10 public buses in Singapore. The "Garden on the Move" campaign is part of a trial to see whether plants can help to reduce the temperatures inside buses so that operators can save the fuel that is spent on air conditioning.
The plants are succulents and grasses that have been specially selected to withstand warm conditions on top of the buses.
The same technology has been used in other parts of the world, including this bus stop in Kuala Lumpur, Malaysia. The plants reduce the temperature and purify the air around the bus stop, as well as providing a home for city wildlife. According to GWS LIving Art, the bus stop can survive 7-10 days without water.