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
Yas Marina Circuit that every corner was 'unique', while double World Champion Fernando Alonso echoed his sentiments, stating that it was enjoyable because there was always something to do. Force India's Adrian Sutil rated the circuit as being better than Formula One's other night race in Singapore as he felt there was too much light at Marina Bay. Not all of the drivers were complimentary, with Giancarlo Fisichella expressing a particular dislike of the pit exit, which dips under the main circuit by way of a tunnel. Although the pit exit remained free of incidents for the early practice sessions, Fisichella claimed that