What is the purpose of a breathalyzer in a DUI stop?

The purpose of a breathalyzer during a DUI stop is to determine the driver's blood alcohol concentration (BAC) and the degree of impairment. This tool analyzes the breath of the driver to estimate the amount of alcohol present in their system. When a law enforcement officer suspects that a driver may be operating a vehicle under the influence of alcohol, the breathalyzer serves as a crucial device to provide immediate evidence of impairment.

By accurately measuring BAC, the breathalyzer can help officers make informed decisions about whether a driver is legally intoxicated. Different jurisdictions have established legal limits for BAC, and exceeding these limits can lead to penalties, including arrest and charges of DUI.

The other options do not align with the primary function of the breathalyzer. It does not measure vehicle speed, as that would be the task of speed detection devices like radar guns. Checking for vehicle insurance is unrelated to determining impairment; it's a separate aspect of traffic law enforcement. Lastly, assessing the driver's overall health does not fall under the breathalyzer's function, as it is specifically designed for measuring alcohol levels rather than general health conditions.