Law On Alcohol/Drug Impaired Driving

What is the Law?

As per section 185 of the Motor Vehicles Act, 1988 as amended in 2019 Whoever, while driving, or attempting to drive, a motor vehicle:

1. has in his blood, alcohol exceeding 30 mg. per 100 ml. of blood detected in a test by a breath analyser (or in any another test including a laboratory test,] or
2. is under the influence of a drug to such an extend as to be incapable of exercising proper control over the vehicle, shall be punishable for the first offence with imprisonment for a term which may extend to six months, or with fine [of ten thousand rupees], or with both; and for a second or subsequent offence, with imprisonment for a term which may extend to two years, or with fine] of fifteen thousand rupees] or with both.
Further as per Sector 20 (2) of Motor Vehicle Act 1988, his/her driving license shall be disqualified for a period of not less than six months. As per Section 22(2) of Motor Vehicle Act 1988, if a person, having been previously convicted of an offence punishable under section 185 is again convicted of an offence punishable under that section, the Court, making such subsequent conviction, shall, by order, cancel the driving licence held by such person. As per Section 19 of the Motor Vehicles Act, 1988, the overspeeding offender’s driving license shall be disqualified for a period of not less than three months.

Who can ask you to take a Breath Test?

A police officer in uniform or an officer of the Motor Vehicles Department, as may be authorised in this behalf by that department, may require any person driving or attempting to drive a motor vehicle in a public place to provide one or more specimens of breath for breath test there or nearby, if such police officer or officer has any reasonable cause to suspect him of driving under the influence of alcohol/drug. In case the motor vehicle being driven by such a person is involved in an accident in a public place he may be asked to provide one or more specimens of breath for breath test at the hospital (in case he is hospitalized) or otherwise on the spot or at the nearest Police Station. If it appears to the police officer in uniform, in consequence of a breath test so carried out by him on any such person that he has alcohol in his blood beyond the permissible limit, he may arrest that person without warrant except while that person is hospitalized. The police officer can also arrest such a person if he refuses to or fails to take the breath test. In case of heavy intoxication the suspect may actually 'fail to' provide a specimen of his breath, as most devices require a fairly long and continuous blowing of breath into the mouthpiece. Any person so arrested must, within two hours of his arrest, be subjected to a medical examination by a registered medical practitioner (described below) failing which; he must be released from custody.

What is a Breath Test? A 'breath test', means a test for the purpose of obtaining an indication of the presence of alcohol in a person's blood carried out on one or more specimens of breath provided by that person, by means of a device of a type approved by the Central Government.

When does one take a Laboratory Test?

The breath test is, however, basically a preliminary screening test of the suspect to be followed by a more reliable and confirmatory Laboratory Test. The preliminary screening is necessary as it is not practicable to administer a full-fledged laboratory test in the field conditions. The preliminary screening makes the basis for the police officer's suspicion more scientific, objective and credible, thus minimizing the possibility of any innocent of being unnecessarily subjected to the inconvenience of a laboratory test. The police officer may thus require any person, who has been arrested for alcohol/drug impaired driving, while he is at the police station, to provide to such registered medical practitioner as may be produced by such police officer, a specimen of his blood for a laboratory test.

Presumption Of Unfitness To Drive: If it is proved that the accused, when requested by a police officer at any time to do so, had refused, omitted or failed to consent to the taking of or providing a specimen of his breath for a breath test or a specimen of his blood for a laboratory test, his refusal, omission or failure would be presumed to be proof of the fact that he/she was indeed driving in an alcohol/drug impaired condition.

About Breath tests (under section 203 of the Motor Vehicles Act 1988)

2[(1) A police officer in uniform or an officer of the Motor Vehicles Department, as may be authorised in this behalf by that Department, may require any person driving or attempting to drive a motor vehicle in a public place to provide one or more specimens of breath for breath test there or nearby, if such police officer or officer has any reasonable cause to suspect him of having committed an offence under section 185.
Provided that requirement for breath test shall be made (unless, it is made) as soon as reasonably practicable after the commission of such offence.

• 1. If a motor vehicle is involved in an accident in a public place and a police officer in uniform has any reasonable has any reasonable cause to suspect that the person who was driving the motor vehicle at the time of the accident had alcohol in his blood or that he was driving under the influence of a drug referred t in section 185 he may required the person so driving the motor vehicle, to provide a specimen of his breath for a breath test-
  • a.) in the case of a person who is at a hospital as an indoor patient at the hospital,
  • b.) in the case of any other person, either at or near the place where the requirement is made, or, if the police officer thinks fit, at a police station specified by the police officer.


• 2. Provided that a person shall not be required to provide such a specimen while at a hospital as an indoor patient if the registered medical practitioner in immediate charge of his case is not first notified of the proposal to make the requirement or objects to the provision of a specimen on the ground that its provision or the requirements to provide it would be prejudicial to the proper care or treatment of the patient.


• 3. If it appears to a police officer in uniform, in consequence of a breath test carried out by him on any person under sub-section (1) or sub-section (2), that the device by means of which the test has been carried out indicates the presence of alcohol in the person's blood, the police officer may arrest that person without warrant except while that person is at a hospital as an indoor patient.


• 4. If a person, required by a police officer under sub-section (1) or sub-section (2) to provide a specimen of breath for a breath test, refuses or fails to do so and the police officer has reasonable cause to suspect him of having alcohol in his blood, the police officer may arrest him without warrant except while he is at a hospital as an indoor patient.


• 5. A person arrested under this section shall while at a police station be given an opportunity to provide a specimen of breath for a breath test there.


• 6. The results of a breath test made in pursuance of the provisions of this section shall be admissible in evidence.

Explanation- For the purposes of this section, "breath test", means a test for the purpose of obtaining an indication of the presence of alcohol in a persons' blood carried out, on one or more specimens of breath provided by that person, by means of a device of a type approved by the Central Government, by notification in the Official Gazette, for the purpose of such a test.

What are Breath Alcohol Testing Devices?

When a person drinks an alcoholic beverage, about 20 percent of the alcohol is absorbed in the stomach and about 80 percent is absorbed in the small intestine. After absorption, the alcohol enters the bloodstream and dissolves in the water of the blood. The blood carries the alcohol throughout the body. The alcohol from the blood then enters and dissolves in the water inside each tissue of the body (except fat tissue, as alcohol cannot dissolve in fat). Once inside the tissues, alcohol exerts its effects on the body. The observed effects depend directly on the Blood Alcohol Concentration (BAC), which is related to the amount of alcohol consumed. The BAC can rise significantly within 20 minutes after having a drink. Once absorbed by the bloodstream, the alcohol leaves the body in three ways: The kidney eliminates 5 percent of alcohol in the urine, the lungs exhale 5 percent of alcohol, which can be detected by breathalyzer devices and the liver chemically breaks down the remaining alcohol into acetic acid. As a rule of thumb, an average person can eliminate 15 ml of alcohol per hour. The BAC increases when the body absorbs alcohol faster than it can eliminate it. Alcohol intoxication is legally defined in terms of the level of BAC. However, taking a blood sample in the field for later analysis in the laboratory is not practical or efficient for detaining drivers suspected of driving while impaired. Urine tests for alcohol are just as impractical in the field as blood sampling. What is needed is a way to measure something related to BAC without invading a suspect's body. The Breath Alcohol Testing Devices provide one such non-invasive technique of estimating the BAC with great accuracy.

Principle of Breath Testing

Alcohol that a person drinks shows up in the breath because it gets absorbed from the mouth, throat, stomach and intestines into the bloodstream. Alcohol is not digested upon absorption, nor chemically changed in the bloodstream. As the blood goes through the lungs, some of the alcohol moves across the membranes of the lung's air sacs (alveoli) into the air, because alcohol will evaporate from a solution -- that is, it is volatile. The concentration of the alcohol in the alveolar air is related to the concentration of the alcohol in the blood. As the alcohol in the alveolar air is exhaled, the breath alcohol-testing device can detect it. Instead of having to draw a driver's blood to test his alcohol level, an officer can test the driver's breath on the spot and instantly know if there is a reason to arrest the driver. Because the alcohol concentration in the breath is related to that in the blood, you can figure the BAC by measuring alcohol on the breath. The ratio of breath alcohol to blood alcohol is 2,100:1. This means that 2,100 milliliters (ml) of alveolar air will contain the same amount of alcohol as 1 ml of blood. The legal standard for drunkenness across the United States ranges from 0.10 to 0.08. If a person's BAC measures 0.08, it means that there are 0.08 grams (i.e., 80 mg) of alcohol per 100 ml of blood. The American Medical Association says that a person can become impaired when the blood alcohol level hits 0.05. Exhaled air can be categorized into essentially three types of samples: Tidal Breath air (the normal shallow breath), Reserve Breath air (exhaled on exertion-faster but not deeper breathing) and Alveolar Breath air (deep lung air). Since breath testing instruments are intended to measure indirectly the concentration of alcohol in the blood, it is essential for accuracy that the breath sample captured by the instrument for analysis be representative of the air in the alveoli of the lung, because it is in the alveoli that the 2100:1 equilibrium ratio between alcohol in the breath and alcohol in the blood occurs.

Types of Breath Alcohol Testing Devices

There are three major types based on different principles of working. Regardless of the type, each device has a mouthpiece, a tube through which the suspect blows air, and a sample chamber where the air goes. The rest of the device varies with the type. Breathalyzer - uses a chemical reaction involving alcohol that produces a color change. To measure alcohol, a suspect breathes into the device. The breath sample is bubbled in one vial through a chemical mixture which changes colour when it reacts with the alcohol; the degree of the color change is directly related to the level of alcohol in the expelled air. To determine the amount of alcohol in that air, the reacted mixture is compared to another vial of un-reacted mixture in the photocell system, which produces an electric current that causes the needle in the meter connected to the photocells to move from its resting place. The operator then rotates a knob to bring the needle back to the resting place and reads the level of alcohol from the knob -- the more the operator must turn the knob to return it to rest, the greater the level of alcohol.

Intoxilyzer - detects alcohol by Infrared (IR) Spectroscopy that identifies molecules based on the way they absorb IR light. Molecules are constantly vibrating, and these vibrations change when the molecules absorb IR light. The changes in vibration include the bending and stretching of various bonds. Each type of bond within a molecule absorbs IR at different wavelengths. So, to identify ethanol in a sample, you have to look at the wavelengths of the bonds in ethanol (alcohol) and measure the absorption of IR light. The absorbed wavelengths help to identify the substance as ethanol, and the amount of IR absorption tells you how much ethanol is there.

Alcosensor III or IV - detects a chemical reaction of alcohol in a fuel cell. The fuel cell has two platinum electrodes with a porous acid-electrolyte material sandwiched between them. As the exhaled air from the suspect flows past one side of the fuel cell, the platinum oxidizes any alcohol in the air to produce acetic acid, protons and electrons. The electrons flow through a wire from the platinum electrode. The wire is connected to an electrical-current meter and to the platinum electrode on the other side. The protons move through the lower portion of the fuel cell and combine with oxygen and the electrons on the other side to form water. The more the alcohol that gets oxidized, the greater the electrical current that is produced. A microprocessor measures the electrical current and calculates the BAC.

Roadside Sobriety Tests

The common physical/mental manifestations of alcohol/drug impairment may be assessed through standardized roadside tests to identify impaired persons. The commonly used tests in the U.S. include- HGN Test & Divided Attention Tests. HGN Testing- Horizontal Gaze Nystagmus is an involuntary jerking of the eyeball which occurs naturally as the eyes gaze to the side. Under normal circumstances, nystagmus occurs when the eyes are rotated at high peripheral angles. However, when a person is impaired by alcohol, nystagmus is exaggerated and may occur at lesser angles. An alcohol-impaired person will also often have difficulty smoothly tracking a moving object. In the HGN Test, the officer observes the eyes of a suspect as the suspect follows a slowly moving object such as a pen or small flashlight, horizontally with his eyes. The examiner looks for three indicators of impairment in each eye: if the eye cannot follow a moving object smoothly, if jerking is distinct when the eye is at maximum deviation, and if the angle of onset of jerking is within 45 degrees of center. If, between the two eyes, four or more clues appear, the suspect likely has a BAC of 0.10 or greater.

Divided Attention Tests- require a suspect to listen to and follow instructions while performing simple physical movements. Impaired persons have difficulty with tasks requiring their attention to be divided between simple mental and physical exercises that are easily performed by most sober people.

Walk-And-Turn Test

The subject is directed to take nine steps, heel-to-toe, along a straight line. After taking the steps, the suspect must turn on one foot and return in the same manner in the opposite direction. The examiner looks for seven indicators of impairment: if the suspect cannot keep balance while listening to the instructions, begins before the instructions are finished, stops while walking to regain balance, does not touch heel-to-toe, uses arms to balance, loses balance while turning, or takes an incorrect number of steps.

One-Leg Stand Test

The suspect is instructed to stand with one foot approximately six inches off the ground and count aloud by thousands (one thousand-one, one thousand-two, etc.) Until told to put the foot down. The officer times the subject for a 30 seconds. The officer looks for four indicators of impairment, including swaying while balancing, using arms to balance, hopping to maintain balance, and putting the foot down.