Generally speaking, no. This means if you are stopped on suspicion of DUI and asked to perform field sobriety tests (FSTs), you can lawfully refuse to do so. In fact, most criminal defense attorneys and DUI attorneys recommend that you politely refuse to take FSTs because they are more likely to hurt than help your case in court.
Note that you can also legally refuse a preliminary alcohol screening (PAS) test. A PAS test is essentially a roadside breathalyzer test, conducted prior to a DUI arrest, that officers use to measure your blood alcohol content (BAC).
But note that under a state’s implied consent law, you are generally required to submit to a breath test or blood test if you were properly arrested for DUI. You can still decline to take a test under these laws, but it can result in:
- a driver’s license suspension, and
- possible enhanced DUI penalties if you are later convicted of drunk driving.
1. Do you have to perform field sobriety tests?
In general, no. Under the DUI laws of most states, FSTs are voluntary. This means you can refuse to take them without penalty if you are stopped after police have probable cause that you are driving while intoxicated.1
Note that field sobriety tests are simply an investigative tool that police officers use to determine whether a DUI suspect is under the influence of alcohol and/or drugs. There are typically not mandatory by any means.
In fact, most DUI defense lawyers and law offices advise people to politely decline to take them. This is because:
- test results can be used against you in court,
- law enforcement officers typically have already made a decision as to your level of impairment prior to administering the tests, and
- you can easily fail the tests even if you are not guilty of drunk driving (for example, because of weather conditions and the shoes you are wearing).
2. What are the main types of FSTs?
While dozens of FSTs have been devised, the National Highway Traffic Safety Administration (NHTSA) has produced three main standardized field sobriety tests. These are the:
- horizontal gaze nystagmus test (HGN), where you have to follow the tip of a small pen or other stimulus with your eyes while keeping your head still,
- walk-and-turn test (WAT), where you have to take nine heel-to-toe steps in a straight line, turn, and walk back towards the officer, and
- one-leg stand test (OLS), where you have to stand on one foot for a certain period of time.2
3. Can you refuse a preliminary alcohol screening test?
Many states say that most drivers can legally refuse to take a PAS test. Note, though, that some exceptions may apply under the laws of the state in which you received your DUI charge in.
A preliminary breath test is a roadside breath test. Police officers use the test to measure your BAC level prior to making a DUI arrest.
Like a field sobriety test, a PAS test is a tool law enforcement use in investigating whether you are in fact a drunk driver.
Note that the results of a PAS test can be used against you in court. For this reason, most DUI attorneys advise drivers to refuse to take them.
4. What about a breath or chemical test post arrest?
Most states say that you cannot refuse these tests without receiving some sort of penalty.
Most jurisdictions in the U.S. have “implied consent laws.” These laws generally require you to submit to a breath or chemical test if you have been arrested on suspicion of DUI.
The purpose of an implied consent law is to help police officers measure your blood alcohol content post arrest.
You can still refuse to take a breath or blood test under these laws, but if you do, most state laws say that your state’s DMV can suspend your driving privileges for six to twelve months.3
Suspension times will likely increase for those drivers with prior DUI convictions.
Further, a BAC test refusal can lead to enhanced DUI penalties if you are later convicted of drunk driving. Enhanced penalties mean that a judge can impose a harsher sentence than for a normal DUI (for example, one with additional jail time).
Some states also provide that, should your DUI case go to trial, your refusal to take a chemical test will be admissible as evidence of guilt.4
Legal References:
- See, for example, the California case of People v. Jackson (2010), 189 Cal.App.4th 1461.
- See DWI Detection and Standardized Field Sobriety Testing, March 2015 Edition, Participant Guide.
- See, for example, Florida Motor Vehicle Code 316.1932. Some states may also impose a driver’s license revocation for a test refusal.
- See, for example, Colorado Rev Stat 42-4-1301.
