State liquor laws as enablers for impaired driving and other impaired behaviors.

In theory, liquor control laws are meant to promote temperance. In most states, however, a purveyor of alcoholic beverages does not have to stop serving a customer until she/he appears "intoxicated"; this means that many people continue to be served alcohol long after they have reached the legal limit for impaired driving, .10 per cent blood alcohol concentration (BAC). Objective impairment and increased injury risk substantially precede clinical signs of intoxication. State liquor control laws should be changed to establish a maximum permissible number of drinks that may be served so that patrons are unlikely to exceed a maximum BAC (.10 per cent or .15 per cent) and to adopt a BAC of .10 per cent or .15 per cent as presumptive evidence that a patron has been served too much. Currently five states have a cutoff based at least in part on BAC, while the remaining states either have cutoffs based on appearance of intoxication or no cutoff at all.