DOT post-accident drug testing is required by the FMCSA after certain types of crashes involving a commercial motor vehicle. If your driver is involved in a fatal accident, receives a citation after an injury crash, or a vehicle is towed due to disabling damage, the driver must complete alcohol testing within 8 hours and drug testing within 32 hours.

These strict timelines ensure accountability and help protect your company’s DOT compliance record.

To manage a crash response properly, you first need to understand the basics—starting with what DOT post-accident drug testing is and when it applies.

What is DOT Post Accident Drug Testing?

DOT Post Accident Drug Testing is a specific type of drug testing that the US Department of Transportation (DOT) requires commercial drivers to undergo following a DOT recordable accident.

This type of DOT drug testing is intended to help ensure that drivers were not impaired by drugs or alcohol when a crash happened and is a critical part of your DOT drug and alcohol program compliance.

The DOT has established specific regulations for post-accident drug and alcohol testing which must be followed by all regulated commercial trucking companies and drivers who hold a commercial drivers license.

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Is DOT Drug Testing and Alcohol Testing Required?

Overall, DOT Post Accident Drug Testing helps ensure that all commercial drivers abide by federal laws regarding substance use while operating vehicles on public roads.

By doing so, it helps protect both those behind the wheel and everyone else sharing our roads from potential harm caused by impaired driving.

Check out our short video on Post Accident Testing Here:

When is DOT Post Accident Drug Testing Required?

Quick Answer:

• Drug test must occur within 32 hours of a DOT-reportable accident
• Alcohol test must occur within 8 hours of the accident

Surprisingly, a trucking company doesn’t usually have to conduct post-crash drug testing or alcohol testing unless there was a fatality or the driver received a citation from a DOT reportable accident.  

DOT post accident drug testing and breath alcohol testing is required for CDL drivers who are subject to FMCSA regulations when they’re involved in an accident that results in a fatality.

In reality, this only accounts for around 1% of all crashes involving large trucks or buses. 

They’re also required to undergo both drug and alcohol testing if they receive a citation related to their involvement in a DOT reportable accident AND: 

the crash results in “bodily injury requiring immediate medical treatment away from the scene” or

“Disabling damage to any motor vehicle requiring it to be towed away”. 

The citation is the key! 

No drug or alcohol testing is required If a truck driver is involved in a crash and:

Nobody passes away at the scene or 

They don’t receive a citation 

There is a great deal of misunderstanding and truck stop compliance advice around this specific topic. 

Some may say that a motor carrier must test an employee driver or independent contractor just if they’re involved in a “DOT reportable accident”.  

What is a DOT Reportable Accident?

A DOT reportable accident is defined by the DOT Drug & alcohol post-accident requirements per §382.303:

Results in a fatality

Results in bodily injury requiring immediate medical treatment away from the scene or

Results in disabling damage to any motor vehicle requiring it to be towed away

The driver MUST be cited in the DOT reportable accident or there must be a fatality at the scene in order for DOT post accident drug testing or breath alcohol tests to be required. 

What is the DOT Post Accident Drug Testing Time Frame?

Quick Answer:

• Drug test must occur within 32 hours of a DOT-reportable accident

Per CFR Part 40, DOT testing for drugs must be completed within 32 hours of a DOT reportable accident involving a commercial motor vehicle.

If you’re unable to get a driver tested during this time frame, you must clearly document and be prepared to provide evidence as to why the testing wasn’t completed within the set time limit. 

What is the DOT Post Accident Alcohol Testing Time Frame? 

Quick Answer:

• Alcohol test must occur within 8 hours of the accident

DOT Breath Alcohol Testing should be completed within 2 hours of a crash but must be completed within 8 hours of a DOT recordable accident. 

If you’re unable to get a driver tested during this time frame, you must clearly document and be prepared to provide evidence as to why the testing wasn’t completed within the set time limit. 

DOT Post Accident Drug Testing Procedures

The post accident drug testing procedures are very similar to all other types of DOT drug and alcohol testing. Of course, the main difference is that specific time limits don’t apply to the other types of testing. This can be a huge difference. 

It’s a good idea to develop and test a post accident drug testing plan PRIOR to a crash happening.

This should be part of your larger post accident response planning (and yes, you really do need to develop a response). Just including a DOT post accident checklist in each truck cab can have a huge impact on the crash outcome for your company! 

Having your drivers and management team undergo training ahead of time will make the process go much smoother if and when the real thing happens.  

It’s also important to note that a driver must be tested for both drugs and alcohol following a crash, if post accident testing is required. You don’t get to choose one or the other.

Both must be completed!

What if I Fail to Conduct a Post Accident Drug and Alcohol Test?

Nothing good! Not doing both a post accident drug and alcohol test within the required time limits can expose you to serious fines and even put your DOT safety rating at risk.

Once a DOT recordable accident happens, that information is noted on the police report which is ultimately sent to the FMCSA via a DOT accident report. This is the information that shows up in the FMCSA’s Safety Measurement System (SMS) in your Crash CSA BASIC. DOT auditors will review this information when preparing for a DOT audit and ensure that post accident testing was completed as required.

If you fail to complete a required post accident drug and alcohol test, document the reasons that the testing wasn’t completed and retain any evidence.

For example, let’s say that your driver is involved in a DOT reportable accident and post accident testing is required. But, the crash happened at 7:00 pm on a Friday night.

Chances are, all potential testing facilities nearby will be closed or closing soon and you probably won’t be able to get the driver tested before 8:00am on Saturday morning.

In this case, you should document that you attempted to schedule a post-accident alcohol test for the driver but that you couldn’t due to none being opened. I would suggest that you also take some screenshots of your drug and alcohol scheduling system showing that no locations within 100 miles or so were opened as proof of this.

But, be sure to have that driver tested for drug use as soon as possible the next morning. Don’t bother with the alcohol test as the compliance window would have passed at that point. Just document and move on.  

How does Post Accident Testing Work? 

Ideally, you’ll already have a drug testing partner (like My Safety Manager) and your DOT post accident drug testing process will be much easier. 

We work with Abbott Labs, Labcorp and Quest Diagnostics. So, we have access to about 27,000 testing locations across the US. 

The huge size of our drug testing network is very intentional…we need as many options as possible for our pre employment drug test and post accident drug test needs. 

Unfortunately, many truck drivers like to drive during the night to cut down on traffic related delays. 

According to the FMCSA’s Large Truck and Bus Crash Facts: “Thirty-seven percent of all fatal crashes, 24 percent of all injury crashes, and 20 percent of all property damage only crashes involving large trucks occurred at night (6:00 pm to 6:00 am)”.

Coincidentally, most drug and alcohol testing facilities are typically open normalish business hours (between 8:00 am and 5:00 pm local time). 

In other words, a significant number of truck crashes happen when drug and alcohol testing sites are closed. 

So, hitting that 8 hour time limit for alcohol testing can be a challenge. The 32 hour time limit for drug testing is much easier to accomplish.

The only times those become harder to make are crashes that happen early on Friday evenings as most testing facilities are closed on the weekends as well. 

If you’re operations are in a limited area (like an intermodal container hauler, for example), finding an after hours testing facility is usually easier. 

But, if you have a more regional or national presence then this becomes much harder. 

If you don’t take some time before severe crashes happen, you could just be stuck googling “DOT post accident drug testing near me ” and seeing what comes up. Then you (or your driver) will get to do the dial and dash to try and get the testing completed on time. 

Remember, roadside drug tests or alcohol tests done by a police officer doesn’t count as a DOT post accident drug test or alcohol test. Drug and alcohol testing completed at a medical facility at the request of law enforcement doesn’t count either! 

For DOT post accident drug testing purposes, the employer or driver must have a certified specimen collector or Breath Alcohol Technician (BAT) complete the collection and follow all DOT protocols outlined in CFR Part 40.  

Check out our best practices:

DOT Post Accident Drug Testing Best Practices: 

1) Do some pre-crash planning around your major lanes of travel to see if you can find some reliable after hours testing centers. 

2) As soon as possible after the crash, launch your post-accident response procedures.

3) Notify your drug and alcohol testing partner of the crash and/or determine if post accident drug testing and alcohol testing is required.       

4) If testing is required, work on getting your driver to the collection facility as soon as possible. 

5) Be sure to secure a copy of the Chain of Custody form that is given to the driver at the testing facility. 

6) Follow up with your testing partner or the testing facility to make sure that you get the results as soon as possible. 

7) You can share the outcome of the tests with your insurance company. But, don’t share the actual results with anyone due to privacy laws and HIPPA. 

8) If you’re unable to meet the post accident DOT drug testing requirements or DOT alcohol testing timeline, document your efforts and the reasons well.  

9) Consider testing drivers after involvement in any crash, regardless of citation. 

10) Be sure to update your DOT Accident Register with the new crash information. All crashes requiring a post crash test will be required to be listed on this document.

Why is Post Accident Drug Testing Important? 

It’s important that trucking companies adhere to DOT regulations regarding post accident drug and alcohol testing; failure to do so could result in fines and penalties from FMCSA.

Simply failing to conduct a single required DOT post accident drug test or alcohol test could cause you to receive a Conditional Safety Rating after a DOT audit.

Even worse, not testing for the use of drugs and alcohol following an accident could cause serious legal issues if it was a bad accident.

We live in an increasingly litigious society. The costs of both nuclear verdicts and other trucking crash costs continue to skyrocket. 

Anything that you can do to reduce claims costs and the possibilities of a nuclear verdict against you should be beneficial. 

As mentioned in Best Practice number 9 above, testing all drivers involved in crashes is a good business practice. The DOT sets the minimum requirements that must be met in order to be in compliance with FMCSA regulations. If you’re testing above and beyond the requirement, you should be considered a safer motor carrier. 

Just be sure to include this in your DOT Drug and Alcohol Policy and have all drivers sign a receipt saying that they’ve received a copy. 

What Happens If You Fail A Post Accident Drug Test? 

Bad things. 

First, failed DOT drug testing causes you to be immediately removed from all safety sensitive functions. This happens with all DOT drug and alcohol testing and not just DOT post accident drug testing. 

You’ll be required to be evaluated by a Substance Abuse Provider (SAP) and you’ll probably have to complete an assigned treatment or training program. 

Once that program is completed, you’ll be eligible to undergo the FMCSA Return to Duty process. 

This involves passing observed return to duty drug testing and prescribed follow up drug testing for at least 1 year after the SAP releases you from their care. 

Of course, all test results will be reported to the Drug and Alcohol Clearinghouse and you won’t be allowed to return to driving in a commercial role until you pass your return to duty drug testing. 

The entire return to duty process usually takes anywhere from 1+ years to complete.

How to develop a Post Accident Drug Test Policy

When it comes to developing a post accident drug test policy (or any other safety policy for that matter) consistency, ease of use and documentation are all critical. 

First, it’s important to be consistent. The policy should be applied to all members of the same group equally.

If you say that all drivers are going to be tested after a crash, test all drivers. Don’t make exceptions. Exceptions to established policies and procedures are where lawsuits are often won…by the opposing attorneys. So, be consistent. 

Please don’t make your post accident drug test policy so hard to administer that your team has no chance of success from the beginning. 

We would help you design and implement this process as part of our DOT compliance services!

Start with what’s required by the FMCSA drug testing regulations and build from there. Exceeding the minimum required standards is usually a plus, but make the policy reasonable and clear. 

Lastly, if you say that something is going to happen in your policy, you must be able to provide documentation that these things are happening. If you don’t document something, it’s like it never happened!    

DOT Post Accident Drug Testing FAQs

Q: When is a post-accident drug and alcohol test required under DOT rules?

A: A post-accident test is required for operators of commercial motor vehicles (CMVs) under Federal Motor Carrier Safety Administration (FMCSA) regulations after certain qualifying accidents — for instance, a fatality crash, a crash with an injury requiring medical treatment away from the scene, or an accident where a vehicle must be towed and the driver receives a citation. In these situations, alcohol testing must be completed within 8 hours and drug testing within 32 hours.

Q: Who must undergo the test and where?

A: The driver of the CMV involved in the qualifying accident is the focus of the post-accident drug and alcohol test. The tests must be conducted with DOT-certified procedures and at a location equipped to handle the specimen collection according to DOT rules.

Q: What substances and tests are used in a DOT post-accident scenario?

A: For alcohol: typically a breath test administered via a DOT-approved device, completed within the specified time limit. For drugs: usually a urine sample (and in some circumstances other specimen types) that tests for the five-panel standard (e.g., marijuana metabolite, cocaine metabolite, amphetamines, opioids, PCP).

Q: What happens if the test is not completed within the required timeframe?

A: If testing isn’t done within the required 8-hour (alcohol) or 32-hour (drugs) window, the employer must document the reasons for the delay or inability to test. Failure to test without proper documentation can expose the carrier to compliance issues.

Q: Can the driver continue performing safety-sensitive duties while awaiting results?

A: Yes — subject to employer policy and DOT rules — the driver may continue unless otherwise directed by law enforcement, the employer, or regulations. However, the employer must still follow all testing, documentation and reporting requirements.

Q: What are the employer’s responsibilities after a qualifying accident?

A: The employer must: identify when a post-accident test is required, ensure the driver is informed and transported for testing, maintain documentation of the accident and test timing, preserve the records per DOT rules, and update drug & alcohol policies and training accordingly.

Q: What should a motor carrier’s policy include to ensure compliance?

A: A compliant policy should define safety-sensitive functions, specify when post-accident testing occurs, outline sample collection procedures (time limits, modes, chain-of-custody), explain consequences for a positive test or refusal, and state documentation retention practices.

Q: How long must accident and testing records be kept?

A: Records related to DOT drug and alcohol testing (including post-accident testing) must be retained for prescribed periods under DOT regulations. Generally, the employer should store these records securely for at least five years (or as mandated by the specific statute or regulation that applies).

Q: What happens if a driver refuses to submit to a required post-accident test or tests positive?

A: A refusal or verified positive test result triggers the same consequences as other violations under the DOT drug and alcohol program: the driver may be removed from safety-sensitive duties, must undergo the required evaluation and return-to-duty process, and the employer must follow the mandated follow-up testing.

Q: Why is rapid response and proper documentation critical after an accident?

A: Because the timeframes are tight (8 hours/32 hours), any delay or lack of documentation may compromise compliance, expose the carrier to liability or regulatory action, and hinder the ability to defend the company’s actions in the event of audit or investigation.

Regulatory References

These federal regulations and FMCSA resources establish when post-accident DOT drug/alcohol testing is required and how it must be conducted.

• 49 CFR Part 382 — Controlled Substances and Alcohol Use and Testing
• 49 CFR § 382.303 — Post-accident alcohol and controlled substances testing
• 49 CFR Part 40 — DOT Procedures for Workplace Drug and Alcohol Testing Programs
• 49 CFR § 40.213 — Post-accident drug testing procedures and time limits
• 49 CFR § 40.255 — Post-accident alcohol testing procedures and time limits
• 49 CFR Part 382 Subpart G — FMCSA Drug & Alcohol Clearinghouse (reporting violations and RTD status)
• 49 CFR § 390.15 — Accident register requirements

About My Safety Manager:

We want our clients to be “Audit Ready” at all times. So, we handle their fleet safety and DOT compliance programs for them.

Our specialized safety management solutions help deliver results—safe drivers out on the road who are staying compliant with FMCSA regulations.

We’re a leading provider of fleet safety and trucking compliance services for fleets of all sizes.

We work with you to create compliance systems that meet your unique needs, taking what’s typically far too much work off your plate so you have more time to grow your business.

For more information about how we may be able to help you with this or similar issues, please reach out to us at www.MySafetyManager.com.

About The Author

Sam Tucker is the founder of My Safety Manager, a DOT compliance and fleet safety consulting firm that helps trucking companies stay audit-ready and reduce risk. With over 20 years of experience guiding fleets through FMCSA regulations, CSA score improvement, and trucking risk management, Sam has worked with carriers of all sizes — from small family operations to over 900-unit fleets. He regularly publishes practical fleet safety tips, compliance checklists, and training resources to help carriers avoid costly DOT audit violations and operate more safely.

When he’s not helping fleets improve safety and compliance, Sam enjoys spending time with his family, cooking, and reading.