The changes to the 2012 Regulations have been approved by the Formula One Commission.
One set of dry-weather tyres may now be carried over to Saturday if both Friday sessions are declared wet; it is hoped that this will result in teams carrying out more laps on Saturday.
Changes have been made to the personnel curfew to ensure the rest periods remain constant throughout the season, irrespective of the timing of practice sessions at particular events.
The race director may now prohibit the use of the adjustable rear wing (DRS) if he feels visibility is too poor in wet conditions. This has been done as a result of safety concerns over large speed differentials between cars.