Post-accident testing is where well-run programs most often get it wrong in both directions — testing when no test was required, and failing to test when one was. The criteria are specific, and "there was an accident" is not one of them.
Start here: not every accident triggers a test
This is the single most important correction to make. 49 CFR § 382.303 sets out conditions, and a test is required only when the facts meet them. Testing everyone after every incident is not a conservative reading of the rule — it is a different rule, and it has its own costs.
The alcohol and controlled-substances criteria
For both alcohol and controlled-substances testing, a test is required following an accident when:
- The accident involved a fatality. No further condition applies. If someone died, the surviving driver is tested.
For accidents without a fatality, a test is required when the driver receives a citation under State or local law for a moving traffic violation arising from the accident, and one of the following is also true:
- The accident involved bodily injury to a person who, as a result of the injury, immediately received medical treatment away from the scene; or
- One or more motor vehicles incurred disabling damage requiring the vehicle to be transported away from the scene by a tow truck or other vehicle.
Both halves must be present. A citation alone does not require a test. Disabling damage alone does not require a test.
The condition that trips people up
The citation is the hinge, and it creates a timing problem: a citation may not be issued at the scene. It may arrive days later.
This is why the regulation frames the duty around what the employer knows and when. If the citation criteria are not met, no test is required — even if the accident looked serious. If a citation is issued later and the other condition was met, the testing window may already have closed.
Two practical implications:
- Do not wait at the scene for certainty you cannot get. Work the criteria you can establish.
- Record the reasoning at the time. If a test was not conducted, the record of why is what defends the decision later.
The time windows
Alcohol: the employer must test within 2 hours. If the test is not administered within 2 hours, the employer must prepare and maintain a record stating why. If it is still not administered within 8 hours, the employer must cease attempts and prepare and maintain the record.
Controlled substances: the employer must test within 32 hours. If the test is not administered, the employer prepares and maintains a record stating why.
Those records are not optional paperwork. They are the affirmative evidence that the employer tried.
The driver's obligation to remain available
A driver who is subject to post-accident testing must remain readily available. A driver who leaves the scene before the employer has satisfied the testing requirement, or who fails to remain available, may be deemed to have refused.
There is an important carve-out: nothing in the section requires the delay of necessary medical attention for injured people, or prohibits a driver from leaving the scene to obtain assistance or necessary emergency medical care.
Tests by other authorities can substitute
Under § 382.303(d), tests conducted by Federal, State or local officials with independent authority can be used to meet the post-accident requirement, provided they conform to applicable legal requirements and the employer obtains the results.
This matters in practice: if law enforcement tested the driver, the employer may not need to duplicate it — but the employer does need to obtain the result.
Who makes the call
The determination is the employer's, made through the DER. This is not something a service agent decides, and it is not something the platform or software decides either. A decision-support tool can walk a DER through the criteria and record the reasoning; the determination remains a human one, made by the person the regulation holds responsible.
Why the reasoning matters more than the outcome
An auditor reviewing a post-accident decision two years later is rarely asking "did you test?" in isolation. They are asking whether the company applied the criteria and can show it.
A record that says "no test — no citation issued, and no disabling damage; vehicle driven from scene" is a defensible decision. A blank space where a decision should be is not, even if the decision was correct.
FAQ
Does every accident require a post-accident test?
No. Under 49 CFR 382.303 a test is required only when the criteria are met: a fatality, or a citation for a moving traffic violation combined with either bodily injury requiring immediate medical treatment away from the scene, or disabling damage requiring a vehicle to be towed.
Is a citation alone enough to require a test?
No. For a non-fatal accident, the citation must be accompanied by either bodily injury requiring immediate off-scene medical treatment or disabling vehicle damage requiring a tow. Both halves must be present.
How long do we have to conduct the test?
Alcohol testing must occur within 2 hours, with a documented explanation if it does not, and attempts cease at 8 hours with a record prepared. Controlled-substances testing must occur within 32 hours, with a record prepared if it does not.
What if the driver needs medical attention?
The regulation does not require delaying necessary medical attention for injured people, and it does not prohibit a driver from leaving the scene to obtain assistance or necessary emergency medical care.
Can a police test satisfy the requirement?
Yes, in the circumstances described in 49 CFR 382.303(d). Tests conducted by Federal, State or local officials with independent authority may be used if they conform to applicable legal requirements and the employer obtains the results.
What should we record if we decide no test is required?
Record the criteria you applied and the facts you established — whether a citation was issued, whether anyone received immediate medical treatment away from the scene, and whether a vehicle required towing. The reasoning captured at the time is what supports the decision later.
This article describes federal requirements under 49 CFR Parts 40 and 382 and is provided for general information. It is not legal advice. Employers remain responsible for their own compliance decisions and should consult qualified counsel or a DOT specialist about their specific circumstances.