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['Drug and Alcohol Testing - DOT']
['Random alcohol and drug testing- Motor Carrier']
04/14/2026
ez Explanations
Regardless of testing cycles, the math formula and concepts used in generating a DOT random drug and alcohol selection are the same.
Scope
This regulation applies to all motor carriers who operate a commercial motor vehicle (CMV) requiring a commercial driver’s license (CDL) in interstate, intrastate, or foreign commerce and any consortium/third-party administrator who performs a random selection on behalf of a motor carrier.
Regulatory citations
- 49 CFR 382.305 — Random testing
Key definitions
- Commercial driver’s license (CDL): A license issued to an individual by a state or other jurisdiction of domicile, in accordance with the standards contained in 49 CFR 383, to an individual which authorizes the individual to operate a class of a commercial motor vehicle.
- Commercial motor vehicle (CMV): A motor vehicle or combination of motor vehicles used in commerce to transport passengers or property if the motor vehicle is a:
- Combination Vehicle (Group A) — Having a gross combination weight rating (GCWR) or gross combination weight (GCW) of 26,001 pounds or more, whichever is greater. The towed unit(s) must have a gross vehicle weight rating (GVWR) or gross vehicle weight (GVW) of more than 10,000 pounds, whichever is greater; or
- Heavy Straight Vehicle (Group B) — Having a GVWR or GVW of 26,001 pounds or more, whichever is greater; or
- Small Vehicle (Group C) — Does not meet Group A or B requirements but is either:
- Designed to transport 16 or more passengers, including the driver; or
- Of any size and is used in the transportation of hazardous materials as defined in 383.5.
- Safety-sensitive function: Drivers are considered to be performing a safety-sensitive function during any period in which they are actually performing, ready to perform, or immediately available to perform any safety-sensitive functions.
Safety-sensitive functions shall include:- All time at an employer or shipper plant, terminal, facility, or other property, or on any public property, waiting to be dispatched, unless the driver has been relieved from duty by the employer;
- All time inspecting equipment as required by 392.7 and 392.8 or otherwise inspecting, servicing, or conditioning any commercial motor vehicle at any time;
- All time spent at the driving controls of a commercial motor vehicle in operation;
- All time, other than driving time, in or upon any commercial motor vehicle except time spent resting in a sleeper berth (a berth conforming to the requirements of 393.76 of this sub-chapter);
- All time loading or unloading a vehicle, supervising, or assisting in the loading or unloading, attending a vehicle being loaded or unloaded, remaining in readiness to operate the vehicle, or in giving or receiving receipts for shipments loaded or unloaded; and
- All time repairing, obtaining assistance, or remaining in attendance upon a disabled vehicle.
Summary of requirements
The Federal Motor Carrier Safety Administration (FMCSA) requires motor carriers to complete a minimum number of random DOT drug and alcohol tests based on the carrier’s average number of drivers in positions requiring a commercial driver’s license (CDL). By the end of a calendar year, the number of completed:
- Drug tests must equal at least 50 percent of the average number of CDL driving positions.
- Alcohol tests must equal at least 10 percent of the average number of CDL driving positions.
The following scenario outlines how a motor carrier manages its quarterly random selections. The example has a slight fluctuation in driver positions from quarter to quarter.
First quarter
First, determine who should be included in the driver master. Let’s suppose the first quarter’s pull has 250 CDL driver positions. Based on this, you know — if nothing changes — that you must have 125 drug tests and 25 alcohol tests completed (at a minimum) by the end of the year. You divide 125 and 25 by 4 (the number of testing cycles) and round up. So the first quarter selection would include 32 names for drugs and 7 names for alcohol.
Second quarter
All of the first quarter tests should have been completed at this point. Let’s look at what has changed since last quarter:
- Do you need to make up any tests that were either canceled or not completed in the first quarter? You will need to compensate for these tests somewhere. It could be done during this testing cycle.
- Who should be in your pool? Do you need to add or remove names?
- Are you counting each part-time, intermittent, and occasional position as one driving position?
- Are any drivers on a leave of absence that you expect or know for certain will not return to drive for you? If you don’t anticipate the driver will drive again for you, you may safely remove the name from the list.
With all of this taken into account, suppose your driver positions spike during the second quarter, and you are now up to 300. You do the same mathematical formula as the first quarter. You take 50 percent of the 300, which is 150, divide by 4 (the number of testing cycles), and round up. You arrive at 38 drug tests. You then take 10 percent of 300, which is 30, divide by 4, and round up to reach 8 as the number of alcohol tests this quarter. If you missed any tests last quarter that you want to make up, you would simply add them to these numbers.
Third quarter
By third quarter, all the second quarter tests should have been completed. You look at the same variables as last quarter when preparing for the pull:
- Tests that were canceled or not completed in the second quarter, and
- Adding or removing names.
After reviewing these variables, you should arrive at an accurate number of driver positions for the third quarter. Suppose you had a major shift in numbers to 400 driver positions. You would use the same formula based on 400: 200/4 = 50 drug tests this quarter and 40/4 = 10 alcohol tests this quarter (plus any make-up tests for each test type).
Fourth quarter
Fourth quarter is the selection period in which you need to make sure that all your calculations are correct and that all tests are completed.
If you do not draw names at a higher rate than the minimum and therefore do not have a cushion to work with, it is imperative that the holidays, vacations, and the like do not interfere with sending drivers by the end of the year. All tests must be completed by the end of the calendar year.
On the other hand, you don’t want to end too early in the cycle either because it is the end of the year. Drivers who know that everyone was sent in early December may engage in prohibited behaviors thinking they may not get caught. It is a delicate balance of not too early and not too late.
By fourth quarter, all the third quarter tests need to be completed. You look at the same variables as last quarter when preparing for the pull. After factoring in all these variables, you should arrive at an accurate number of driver positions for the fourth quarter. Let’s suppose you drop back to a lower number due to a slow time of year. Your driver roster has 225 driver positions for fourth quarter.
Before you do your last draw, you need to see where you are for numbers: 250 + 300 + 400 + 225 = 1175/4 = 294 (the average number of drivers for the year).
Based on this, you must have 147 drug tests and 30 alcohol tests by the end of the year. So far you have: 32 + 38 + 50 = 120 drug tests at the end of the third quarter and 7 + 8 + 10 = 25 alcohol tests.
To accomplish the minimum 147 drug tests, you need at least 27 more tests. To achieve the minimum 30 alcohol tests, you need at least 5 names. If you do not select over the minimum for this quarter, you need to make sure that all drivers selected go for the tests and that none are canceled. If you do not have results for all the names selected, you may find yourself missing the annual testing rates or conducting an emergency selection close to the end of the year to meet your compliance numbers.
['Drug and Alcohol Testing - DOT']
['Random alcohol and drug testing- Motor Carrier']
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