(1) It is unlawful for a person under the age of 21 years who has a blood-alcohol concentration of 0.01 percent or greater, as measured by a preliminary alcohol screening test or other chemical test, to drive a vehicle. However, this section shall not be a bar to prosecution under any other provision of law.

(2) A person shall be found to be in violation of subsection (1) of this section if the person was, at the time of driving, under the age of 21 years, and the trier of fact finds that the person had consumed an alcoholic beverage and was driving a vehicle with a blood-alcohol concentration of 0.01 percent or greater, as measured by a preliminary alcohol screening test or other chemical test.