Many drivers have what are referred to as restrictions on their driver's license. These restrictions may be limiting, such as being allowed a maximum number of passengers if you are in the Graduated Licensing Program or having to wear corrective lenses if your eyesight does not meet minimum standards. They may also be empowering as is the case with being allowed to operate air brake equipped vehicles or tow a trailer with a Gross Vehicle Weight over 4, 600 kg. In all cases, restrictions must be obeyed, or the driver will find themselves in difficulty if they are stopped by the police or they are involved in a collision.