Half of Dubai’s taxi fleet will be hybrid vehicles by 2021, the Roads and Transport Authority (RTA) announced on Saturday. Up from the current hybrid fleet size of around 150 hybrid taxis, the number will rise to 4,750 in five years. The hybrid vehicles are powered by a combination of electricity and petrol. The vehicle runs on a self-charging electric motor when it is driven within a speed of 40km/h, exceeding which it shifts to petrol. This translates to a reduction of carbon emissions by up to 30 per cent, compared to a regular vehicle.