One of the most important things in racecar dynamics is the position of the center of gravity (CoG). Each year, designers attempt to shed weight off of the cars and move heavy components lower into the car to lower a car's CoG. With a driver weighing in about 60 to 70 kg, it is vital to also optimise this position while maintaining a reasonably comfortably position for the driver.
Ever since Colin Chapman's bathtub Lotus 21, drivers are somewhat in a lying down position as it keeps the body closer to the ground while creating the benefit of having less frontal area, hence also inducing a potential aerodynamic advantage.
As today's F1 cars are strictly regulated, the driver's positions hardly differ one car from another. In all cases, drivers currently have their feat only marginally lower to the ground that their chin, while the buttocks is only a few centimetres above the ground. This effect is even more pronounced with cars that feature higher noses, as this means the driver's feet are located higher up, at the same time also reducing driver visibility.
The above picture shows a BMW Sauber F1.08 that was cut in half lengthwise, perfectly displaying the position of the driver in the car. Marked with a yellow line is the bottom edge of the driver seat and monocoque. The leftmost vertical edge is where the driver touches the pedals whereas the lowest point is where the driver's buttocks is.
To give the driver the maximum possible comfort in the small cockpit to withstand the forces in such a car, each seat is made specifically for a driver. During the pre-season, each driver takes part of a seat-fitting session at the factory of his team. In this process, an imprint is made from the driver's body, to make it perfectly fit into the available space in a Formula One cockpit. Such a seat is made from carbon fibre, because of its high strength and low weight. It is furthermore refined with polymers, and at some teams covered with a suede inside for comfort and solid positioning. WilliamsF1 and Lotus F1 Team for instance cover their seats with Alcantara, a very comfortable and wear-resistive material. It is important that these materials do not burn, do not increase the temperature of the seat and create as few as possible static electricity because of the friction of the driver in his seat during a race. The outer side of the seat is also often covered with aluminium or gold foil to reduce radiation heat from the engine and KERS heating up the driver.
While a driver firmly fits into his anatomically formed seat, high speed cornering and braking requires 5-point seat belts, currently also a requirements by FIA regulations. In essence that includes a release button at the driver's belly, with a belt going over each shoulder, one to each side around the hips and one fixed to the seat in between the legs. The latter one is required in F1 to prevent drivers from sliding underneath their seat belts under braking or in case of a frontal accident (accidents like these have happened in the past, with fatal consequences).
In case of emergency, such seatbelts can be released by pressing the connection point at the driver's belly. Due to the small size of the cockpit, a driver cannot fasten his seatbelts by himself. Instead, his race engineer does this for him when going out for a run.
Not so long ago, we still saw drivers shifting gears like in normal cars, pulling and pushing a gear stick while keeping the clutch down with a third pedal, exactly as it was in normal road cars. Then, around 1990, John Barnard introduced electronic gear shifting to Formula One, allowing drivers to shift gears with buttons on the steering wheel.
A little later, semi-automatic gearboxes were introduced which made clutch pedals redundant (while the buttons were changed to paddles behind the steering wheel for easier gear shifting). That reduced the cars' pedals to two, and thus allows drivers to brake with their left foot and throttle with their right. The conversion of this however was gradual, as drivers who were used to right foot braking initially opted to continue this way. Rubens Barrichello was the last one to convert, although it took him quite a while to get used to it. In the end however, left foot braking allows drivers to brake earlier after releasing the throttle, allowing for better performance.
The pedals themselves are made from lightweight titanium or aluminium and for some drivers feature special supports on each side of the pedals to prevent the driver's feet slipping off.