The Administration of SFSTs
If a police officer, after approaching a vehicle and asking questions, believes the driver may be drunk or impaired, the police officer will next ask the driver to exit the vehicle and perform a series of tests.
The smart driver will politely decline: "Officer, I do not wish to do these tests."
The officer cannot force a driver to complete any tests or answer any questions. A driver has a right to refuse to answer these questions. The officer may at that point decide to arrest the driver, but, believe me, the officer will have a lot less evidence of drunk driving if the driver has politely refused to perform tests or answer questions. And the driver will be much better able to beat the DWI in court.
The Standardized Field Sobriety Tests (SFST) were first designed by the National Highway and Traffic Safety Administration (NHTSA) in the late 1970s and early 1980s. If performed according to the strict NHTSA guidelines, NHTSA claims that the SFSTs have around an 80 percent accuracy rate. That means that if the person fails the SFSTs and the SFSTs have been done strictly according to NHTSA guidelines, eight (8) out of ten (10) of those people will also be impaired.
The dirty little secret is that SFSTs are almost never administered properly in the field. That's because in the lab, where the SFSTs were designed, scientists could control conditions. But on the street, blinking lights, weather conditions, uneven pavement, gravel, or other conditions mean that these tests are almost always administered improperly.
It's no wonder that so many people - even sober people - fail the SFSTs.