There is a very fine line between having enough alcohol to relax and consuming so much that your celebrations become unsafe. It can be hard to know where to draw the line, as people are notoriously poor judges of their own chemical impairment.
Some bars and restaurants have invested in machinery to protect their patrons while also limiting their own potential liability. Some businesses have chemical breath test devices that consumers can pay to use. Will checking your blood alcohol concentration (BAC) on a commercial testing unit at a bar or restaurant protect you from drunk driving charges?
There is no guarantee a business’s device will be accurate
Obviously, bars would prefer to not have patrons leave and cause drunk driving crashes, as negative publicity could hurt their image with the community and potentially affect their liquor license or insurance rates. However, the choice to provide a breath test device that patrons can pay to use is often simply a way for the company to profit yet again from those patrons.
While the cost itself may be negligible, there is no guarantee of accuracy when you make use of a testing unit at a public business. Such devices typically have warning labels that advise they could be inaccurate for any number of reasons, including a failure of the business to frequently calibrate the device for accurate readings.
You could perform a test, get a reading that makes you feel confident about driving yourself home and then end up arrested. Short of very carefully limiting how much alcohol you consume, it can be difficult to control your BAC or to accurately gauge it while you are out drinking. Understanding the limitations of preventative breath testing could help you avoid a situation where you wind up facing drunk driving charges.