Monte Carlo has thus become the only Formula 1 circuit in which the pits are not facing the track, but rather physically separate it from the pit lane. In 2011, after some accidents that occurred during the race weekend (the Mexican driver Sergio Pérez suffered a rather serious one), the drivers urged a change in the sector between the exit of the tunnel and the "Nouvelle Chicane", complaining (above all) about the disconnection of the road surface and incorrect positioning of the guard rail in the escape route opposite the tunnel. However, these requests were not followed up. In 2015 the "Tabac" curve was re-profiled, slightly anticipating the entrance and thus shortening the track by three meters (from 3,340 to 3,337 today). The building of the circuit takes six weeks, and the dismantling after the race another three weeks. The race circuit is narrow, with many elevation shifts and tight corners. These features make it perhaps the most demanding track in Formula One racing. Although the course has changed many times during its history, it is still considered the ultimate test of driving skills in Formula One. It contains both the slowest corner in Formula One (the Loews Hairpin, taken at just ) and one of the quickest (the flat out kink in the tunnel, three turns beyond the hairpin, taken at ). Due to the tight and twisty nature of the circuit, it favours the skill of the drivers over the power of the cars. However, there is very little overtaking as the course is so narrow and dangerous. Nelson Piquet likened racing round the course to "riding a bicycle around your living room". Prior to 1987, the number of cars starting the race was limited to 20, compared to 26 at other circuits. The famous tunnel section (running under the Fairmont Hotel, marked in grey in the circuit diagram above) is said to be difficult for drivers to cope with due to the quick switch from light to dark, then back to light again, at one of the fastest points of the course. As a result, race outcomes tend to be decided by grid positions as well as pit strategies, and the race is extremely hard on gearboxes and brakes. Several attempts have been made to improve cramped conditions in the pit garages. In 2002, a substantial amount of land was reclaimed from the harbour to slightly change the shape of one section of the circuit; this left more space for new pit garages, which debuted in the 2004 event. The circuit is generally recognised to be less safe than other circuits used for Formula One.