THE FIA has announced a series of changes to the sporting and technical regulations from the start of the 2012 Formula One season.

Chief among the changes is a return to in-season testing for the first time since 2009, with one three-day test to be permitted during the course of the campaign.

There will also be a maximum race time of four hours to avoid a lengthy suspension of an event - such as happened at last season’s rain-hit Canadian Grand Prix. The time of the actual race remains limited to two hours.

Additionally, drivers may no longer cut corners on reconnaissance laps or ’in’ laps in a bid to save fuel, while cars will now be permitted to unlap themselves behind the safety car.

The main change among the technical regulations sees the exhaust tailpipes of cars “strictly regulated in order to ensure that the aerodynamic effect exhaust gases have on the car is kept to an absolute minimum”.

Changes to the 2012 sporting regulations include: Cars may no longer take part in pre-season testing without having passed all crash tests.

There will now be a maximum race time of four hours to ensure that a lengthy suspension of a race does not result in a race that could run up to eight hours if left unregulated.

Before the safety car returns to the pits all lapped cars will be allowed to unlap themselves and then join the back of the pack, ensuring a clean re-start without slower cars impeding those racing for the leading positions.

Cars which were in the pit lane when a race is suspended will now be allowed to re-join the cars on the grid in the position they were in when the race was suspended.

Drivers may no longer leave the track without a justifiable reason, i.e. cutting a chicane on reconnaissance laps or ’in’ laps to save time and fuel.