FORMULA One teams will not be allowed to run three cars at Grand Prix practice sessions next season.

Motorsport's governing body, the FIA, announced the decision following a meeting of the World Motor Sport Council in Barcelona.

In a revised practice and qualifying schedule, Friday's two free practice sessions are being extended by half-an-hour each from 60 to 90 minutes.

The team's third driver will still be able to drive in these sessions but not in a separate vehicle.

Friday practice will also gain exemption from the two-engine rules.

Currently, engines must last for two straight Grands Prix, with any unscheduled changes dropping a driver ten places on the grid.

But this has led drivers to restricting their Friday mileage. The new rule aims to avoid that problem.

With Bridgestone the sole tyre supplier next season, teams will have 14 sets per driver available each weekend, double the current number.

The procedures for following the safety car have also been altered.

Lapped cars will now be allowed past the pace car to avoid holding up the leaders.

Any lapped vehicle lying between cars running on the lead lap will now have to pass the safety car, complete a full circuit to catch up with the pack, and take up a position at the back of the line of cars behind the safety car.