 Complete the following phrase:  Safety standards have improved since the first World Championship Grand Prix at Silverstone in , where there was no medical back-up or safety measures in case of an accident. It was not until the 1960s these were first introduced, as helmets and overalls became mandatory and the FIA assumed responsibility for safety at the circuits. Steps were taken to improve the safety of the Formula One car in the 1970s; the cockpit opening was enlarged allowing the driver to escape more quickly in the event of an accident and outside mirrors became mandatory. The 1980s saw further improvement in the structure of the Formula One car, with the monocoque being made out of carbon fibre instead of aluminium, increasing protection upon impact. Following the 