Here is an interesting article about a product in Minnesota that is in several bars. It is meant to permit drinkers to learn their BAC level before they decide to drive. The article includes a discussion of issues like the rising BAC as alcohol metabolizes and calibration of the devices, but may show promise for a preventive measure that can save lives.
Read about the IntoxBox at:
In Depth: In-bar, pre-car breath test - Minneapolis News and Weather KMSP FOX 9