Circuit de Monaco downhill again to a double right-hander called "Portier," named after region of Monaco, before heading into the famous tunnel, a unique feature of a Formula One circuit. (Until 2009 only one other circuit, Detroit in 1982–88, featured a tunnel, but the F1 series now includes racing at the Yas Marina Circuit in Abu Dhabi, which presents a shorter tunnel at the exit of the pit lane.) As well as the change of light making visibility poor, a car can lose 20–30% of its downforce due to the unique aerodynamic properties of the tunnel. The tunnel also presents a unique problem
Lippo Village International Formula Circuit Karawaci. There are now large trees covering the empty area surrounding one portion of the track, including the one near a mosque. The paddock building has been renovated and currently utilized as an extension of the university, which houses additional classrooms and a computer laboratory. The defunct track is now superseded by BSD City Grand Prix, a street circuit built on Bumi Serpong Damai, Tangerang. Lippo Village International Formula Circuit The Lippo Village International Formula Circuit is a defunct street circuit in Lippo Village Tangerang, Indonesia. The track was confirmed to host a round of the 2008–09 A1 Grand Prix