TWFR General Rule 14 states:

CORNER CUTTING. Drivers must not cut chicanes or other corners. You must keep two tyres on the tarmac at all apexes. Kerbs do NOT count as tarmac! You may fully use the kerbs at the exit or corners but you must not use tarmac run off areas other than for their purpose of regaining control in the event of a mistake. If you should accidentally cut a chicane etc then give back any position(s) gained or defended as soon as it is safe to do so. Serious offenders are liable to a penalty imposed by TWFR HQ.


The following examples help to clarify what this means. Click on the images to open them in a new window at full size.






The right hand tyres are fully on the tarmac (the white line is painted on the tarmac so is part of it).





Here the car is fully on the kerb and none of the wheels are touching the tarmac. This is a clear case of cutting the apex.





The right hand tyres are partly on the tarmac and partly on the kerb. This example is not legal because two tyres are not fully on the tarmac.




Although the left front tyre is fully on the tarmac, the left rear tyre is partly on the kerb. There are not two tyres fully on the tarmac and therefore this is not legal.





None of the tyres are on the tarmac but this is allowed at the exit of a corner.





Here the car has driven onto the tarmac run off area at the exit of the first turn at Silverstone. This tarmac exists only for safety reasons (it used to be a gravel trap) and is not part of the racing surface. It is therefore not allowed to use it.

Penalties
The general rule is that if you should cut an apex or run onto a tarmac run-off area, you will not be penalised if you slow down so that you do not gain an advantage.

Qualifying
It is very important that you slow down if you should accidentally do it in qualifying - if your qualifying lap is found to be illegal then you are likely to receive a penalty during post-race scrutineering. You can use the instant replay system from the race monitor screen to check your lap if you are not sure if it was legal or not. Use the left & right arrow keys to move back & forwards through the monitor replay. CTRL + left arrow key will fast rewind. If you believe your fastest lap to be illegal then report it to the Race Director and advise that you will be starting from the back of the grid.

Race
If you should gain or defend a place by cutting an apex (most likely at a chicane) then you must give up the place as soon as you can safely do so. Failure to do this will likely result in a penalty applied after the race.

Please note that occasional accidental cutting of corners during a race will not be penalised provided that no places are being gained as a result. However, if a driver is cutting a corner or using a tarmac run-off area on a frequent basis then they should expect to be penalised.


It is the driver's responsibility to know whether he is cutting a corner or not. It is no defence to claim that it did not look like you were cutting it from within the car. All drivers are strongly advised to use the replay system to check that their normal lines are legal.