In the United States, a non-signatory country to the Vienna Convention, state vehicle codes generally do not envisage—but do not necessarily prohibit—highly automated vehicles . To clarify the legal status of and otherwise regulate such vehicles, several states have enacted or are considering specific laws. By 2016, seven states (Nevada, California, Florida, Michigan, Hawaii, Washington, and Tennessee), along with the District of Columbia, have enacted laws for automated vehicles. Incidents such as the first fatal accident by Tesla's Autopilot system have led to discussion about revising laws and standards for automated cars.