The minimum drinking age in all states is 21. Local laws against driving while intoxicated are growing stricter. Many bars now serve non-alcoholic drinks for those nominated to do the driving. For non-emergency assistance when traveling, call Travelers' Aid, an organization that specializes in helping distressed travelers, whether American or foreign. Their number can be found in local telephone books, or alternatively, dial 0 and ask the operator.
Most officers are firm, but courteous.
They are more likely to let you off with a verbal reprimand if you are civil and prepared to understand the reason why they've stopped you. The majority of vehicle stop-checks are now recorded on video camera with police officers wired for sound, so anything you say or do will be recorded. Always carry your license and vehicle documentation. Pay fines by mail, or directly to the clerk of the court. In the event of an accident, the advice is to stay in your car with the doors locked until you assess the situation, or until the police arrive.