It is "not possible" to replace every asphalt run-off area with a gravel trap, according to F1 race director Michael Masi.

His comments come amid critiques of the most recent race at Mugello, the Ferrari-owned circuit that highlighted the difference between 'old school' tracks and the more sanitised modern alternatives.

"Mistakes should be punished," said Ferrari's Sebastian Vettel, who said he enjoyed the challenge of Mugello.

1997 world champion Jacques Villeneuve agrees: "The problem with those huge run-off zones at modern circuits is the driver says 'I can take more risks because nothing will happen to me'."

He said drivers of his generation, on the other hand, got used to circuits like Mugello.

"Gravel stops the car much faster, but there is always the risk that the car rolls over," Villeneuve admitted.

The FIA's Masi says that even though gravel is a greater challenge for the drivers, it is "impossible" to simply replace all the asphalt run-off at other circuits.

"I have said more than once that we must look for the most suitable solution for each circuit and then negotiate that with the owners of the circuit.

"This work continues, and we are discussing the issue with the drivers as well, but it will not be possible to apply such a solution everywhere."

Vettel, however, sees another solution.

"Maybe we can have a strip of gravel next to the race track and then asphalt again. That way you can be sure that no benefit is gained from a mistake," he told Speed Week.

"But having only asphalt takes away the character of a circuit and makes it simply too easy for the drivers."