It is unlawful for a person to operate a car, truck, motorcycle, or commercial vehicle if his/her ability to safely operate the vehicle is impaired by the effects of alcohol, illegal drugs etc or if he/she is intoxicated at a level above established DUI standards, such as blood-alcohol concentration (BAC). If a police officer suspects that the driver is intoxicated, he/she can conduct a field sobriety test on the driver and may ask for his or her consent to some form of chemical test. The law requires vehicle drivers to submit to some form of chemical test, such as breath, blood, or urine testing, if suspected of DUI. If the driver refuses to submit to such testing, penalties such as mandatory suspension of a driver's license may be imposed.