Abu Dhabi, Dubai, Sharjah, Ajman, Umm Al Quwain, and Ras Al Khaimah are connected by the E11 highway, which is the longest road in the UAE. In Dubai, in addition to the Dubai Metro, The Dubai Tram and Palm Jumeirah Monorail also connect specific parts of the city. There is also a bus, taxi, abra and water taxi network run by RTA. T1, a double-decker tram system in Downtown Dubai, were operational from 2015 to 2019.