Alcohol and Drugs at the Wheel: Arrest and Testing by Police


Police officers may ask a driver to take tests to determine if their driving ability is affected by alcohol or drugs. Read this article to better understand:

  • what police officers have the right to do to intercept drivers who are not fit to drive;
  • the tests they can pass on to detect alcohol or drugs ;
  • the rights and obligations of drivers at this stage.


Police have several ways to intercept drivers who are not fit to drive

Police have several ways to intercept drivers who are not fit to drive

Police officers may intercept drivers in various circumstances to determine if they are fit to drive.

During a patrol , police watch vehicles and may intercept a driver who seems to be having trouble controlling his vehicle. Thus, a driver may arouse police suspicion if, for example, he drives in a zigzag or can not remain in his lane, if he brakes suddenly or without reason, if he drives too fast or too slow or he is involved in an accident.

During routine random checks to verify that the driver’s license and vehicle documents are in order, police can also check if the individuals are fit to drive. In addition, they can perform roadblocks to check drivers’ alcohol or drug use and driving ability.

Drivers are required to stop at the request of a police officer in uniform, regardless of the circumstances. Once the vehicle is immobilized, the police briefly question the driver about his vehicle and his driving. This may include questions about his use of alcohol or drugs.

First tests done during the interception

Tests made with a detection device

 Tests made with a detection device

Police officers who intercept a driver may order them to test with an alcohol-testing device. The device (often called the “balloon”) can take a breath sample to detect the presence of alcohol in the blood of the driver.

Police officers who suspect the driver of having used drugs may order them to test with a drug-detection device. The device works with a saliva sample and estimates the concentration of the drug in the body.

This test provides police with only an approximate measure and is generally not admitted to court as evidence.

However, the result of the test may provide the police with sufficient reason to take the driver to the police station and make a more specific test.

Physical coordination tests

 Physical coordination tests

Police officers may also pass several movement coordination tests to the driver if they suspect he or she has been using drugs or alcohol .

For example , police may ask them to walk in a straight line and to turn around or balance on one foot while counting aloud.

Police officers may use coordination tests instead of using an approved detection device, or use these two methods successively.

In addition, the police observe the driver throughout their intervention, and can find any indication that he is not fit to drive, for example:

  • a strong smell of alcohol;
  • red or vitreous eyes;
  • the difficulty in articulating while speaking;
  • unexplained equilibrium losses;
  • inconsistency, confusion, mood swings.

The rights and obligations of the driver during these initial screening tests

Police officers must be screened in a very short time from the moment the vehicle is intercepted. Indeed, the driver must know quickly if he can resume the road or if he will be stopped.

At the request of the police, the driver is obliged to:

  • give your driver’s license , registration certificate and proof of insurance of the vehicle ;
  • blow into the approved detection device (alcohol) or provide saliva (drugs);
  • submit to movement coordination tests ;

Warning! The refusal to submit to these tests , without reasonable excuse, is a criminal offense generally punished as severely as the excess of alcohol or drugs itself.

Police officers may also ask questions, but the driver is not legally obliged to answer them. He has the right to remain silent .

Consequences of these first screening tests

Based on these tests and observations, police officers may have reasonable grounds to arrest the driver for having abused alcohol or drugs or for impaired driving.

The police must then allow the driver to consult a lawyer.

The police can:

  • Order the driver to follow them to the station for more specific testing;
  • Suspend his driver’s license;
  • Enter his vehicle.

Refusing to follow the officer for further testing is also a criminal offense.

The driver who is arrested always has the right to remain silent , but if the police officer asks for it, he must give him his name, his address and any other information to confirm his identity.

For more information, see our article rights of a person in case of arrest or detention.

Tests at the police station

Tests at the police station

At the police station, the police can submit further assessments to the driver to determine the exact amount of alcohol or drugs in his blood.

The breathalyzer to accurately measure alcohol in the blood

The breathalyzer is used to take a breath sample to measure the level of alcohol in the blood. It is a more accurate tool than the approved detection device. The result of the breathalyzer test determines whether the amount of alcohol consumed exceeds the allowable limit and, if so, will be used to prove that the driver has committed an offense. It is a qualified technician (also a police officer) who administers this test.


Blood test when the breathalyzer is not feasible

 Blood test when the breathalyzer is not feasible

A police officer may order you to provide a blood sample instead of a breath sample if taking a breath sample is impossible or difficult to perform at the time of arrest because of your physical condition .

For example , an asthmatic person may be unable to breathe hard enough into a breathalyzer to obtain a valid breath sample. The driver may also have injured his mouth or jaw in an accident. In both cases, the police officer may ask him to follow him to the hospital to collect a blood sample.


Additional examinations to detect drug use

When the initial tests give the police reason to believe that the driver’s faculties are impaired by a drug or a combination of alcohol and drugs , the police may order the individual to follow them for further tests. pushed.

The first type of test possible is the taking of a blood sample that can be used to determine the concentration of the drug present in the body of the driver. The sample should be taken by a doctor or a qualified technician.

The other possibility is to have a test with an ” appraiser “. This expert will give the driver a series of physical examinations . For example, he can take his pulse or temperature, examine his pupils or ask him to follow the movement of an object. The appraiser may then order the driver to provide a sample of saliva, urine or blood . In addition, he may ask him to take the breathalyzer test, if he has not already done so.

After passing these tests, charges may be laid and the driver may receive penalties that will have a significant impact in his life . To learn more, read our article on the consequences of driving under the influence of alcohol or drugs.

Alcohol and drugs at the wheel: find out!

  • Alcohol and drugs at the wheel: several offenses
  • Alcohol and driving drugs: the consequences
  • Alcohol and drugs at the wheel: getting your driver’s license