Monaco, home to the most famous Formula One race in the world, is a circuit of contrasts. The principalityï¿½s tight, everyday roads generate the lowest lap speeds of the season ï¿½ Jarno Trulli (Renault/Michelin) averaged 145.880km/h (90.646mph) en route to victory in 2004, which makes it considerably slower than any other race ï¿½ but the proximity of the cars gives spectators a greater impression of speed than almost anywhere else.

The combination of a yacht-fringed Mediterranean location and an illustrious history makes this one of the sportï¿½s crown jewels, a race that every driver longs to add to his CV. This weekend, Michelin will be chasing its 81st F1 world championship victory ï¿½ and a seventh in succession ï¿½ as its partner teams endeavour to maintain their unbeaten start to the season.

Unlike other established circuits, which have been forced to move with the times, Monaco is a glorious anachronism. Conceived by Anthony Noghes, the man after whom the final corner is named, it was first used in 1929 and featured on the inaugural world championship calendar in 1950. It was dropped the following season but reappeared in 1955 and has been omnipresent on the schedule ever since. The 3.340-kilometre (2.075-mile) circuit has changed relatively little over the seasons ï¿½ a modest extension, in 1973, and a new pit complex, opened last season, have been the most significant alterations ï¿½ and this yearï¿½s race will be the 52nd to count towards the world championship.

Michelin has a proud record in Monaco and has been beaten here only once since returning to F1 in 2001. Jody Scheckter (Ferrari) scored the first of Bibendumï¿½s six Monaco victories en route to the 1979 world title. In the intervening years, Gilles Villeneuve (Ferrari, 1981), Alain Prost (McLaren-TAG turbo, 1984), David Coulthard (McLaren-Mercedes, 2002), Juan Pablo Montoya (Williams-BMW, 2003) and Jarno Trulli (Renault, 2004) have all conquered F1ï¿½s most celebrated circuit on Michelin tyres.

Pierre Dupasquier, Michelin motorsport director
ï¿½We are moving from the high-speed sweeps of Barcelona to something completely different - the tight confines of Monaco, with its many slow corners. It is never easy to prepare for the Monaco Grand Prix because it is difficult to find any circuits with similar characteristics. There is nowhere else quite like it.

ï¿½The streets of the principality are an asphalt patchwork that ordinary cars and trucks use on a daily basis. Many parts of the circuit frequently have to be resurfaced and we can but hypothesise about the effects this might have.ï¿½

ï¿½We use fairly soft compounds in Monaco because average lap speeds aren't particularly high and the surface is not too abrasive. Even so, we have to pay careful attention to the rear tyres because cars are forever accelerating fiercely out of slow corners - it is vital that traction control systems are set up correctly, because that can influence wear rates. If a car's rear tyres start to wear more than its fronts, it will begin to oversteer and the driver needs to be much more sensitive with the throttle - especially when exiting slow corners.ï¿½

ï¿½Controlling the rate of tyre wear is always the biggest challenge in Monaco, but Michelin has traditionally done very well here. Having won this race for the past three years, we will be doing our utmost to make sure our partner teams have everything they need to maintain that winning streakï¿½ï¿½

Team perspective:
Willy Rampf, Technical Director, Sauber Petronas
"Being a street track, Monaco's surface characteristics differ from conventional circuits and there isn't much grip. Average speeds are low, too, and there and there are no fast corners, so we use soft tyre compounds. To minimise wear rates we need to run with maximum downforce. It's also crucial to find a set-up that provides smooth, balanced handling with neither understeer nor oversteer.ï¿½

"We finalised our tyre options during a recent test at Le Castellet. Michelin has a very professional approach and provides us with plenty of information. Our relationship is working very well in our first season together."

Technical focus
ï¿½Road surfaceï¿½
The nature of the road surface at Monaco is among its most striking features. Used by regular traffic throughout the year, its characteristics are very distinctive. When considering grip at any venue, you have to weigh up the state of two elements: tyres and the road surface. The latter's characteristics (the type of asphalt and its roughness) and the prevailing conditions (surface cleanliness, rain etc) will influence grip significantly.

To define the grip characteristics of a street circuit, its surface geometry has to be examined and assessed in several ways:

Macroroughness. It contributes to the drainage and storage of water, as well as tyre indentation . Macroroughness occurs due to the size of the aggregates used in the composition of the road surface.

Microroughness. It is mainly responsible for tyre indentation. Microroughness is related to the surface imperfections of the aggregates and sands used in the road surface's composition

The load-bearing surface must also be considered because it determines localised pressures within the tyre's contact patch (as detailed in the Spanish GP preview).

Measurement of macroroughness
Macroroughness can be measured on a road surface, a core sample or a moulding made of the surface.

Measurement of microroughness
Microroughness is assessed by indirect methods. In particular, the level of microroughness is evaluated by taking aggregate surface photos. These photos are then compared with a subjective scale, graduated from 1 (for an extra-smooth surface) to 100 (for a particularly rough surface).

The friction - or grip - co-efficient can only be defined in terms of the relationship between a tyre and the road surface. In an urban setting, road surfaces can be classified in four main categories: