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Legally reviewed by Texas truck accident lawyer Greg Baumgartner and updated July 31, 2026.
A truck driver who drives while affected by alcohol, illegal drugs, or unsafe medicine may be at fault for a crash. The trucking company may also be at fault. It may have failed to test the driver, missed clear warning signs, or kept an unsafe driver on the road.
Fast action matters in these cases. Test results, driver files, truck data, video, and dispatch records can be lost. An early review can show whether the problem began with the driver or with the company’s safety system.
| Key point A positive test can be strong proof, but it does not prove the whole case by itself. The result should match the driver’s actions, witness accounts, company records, and crash data. |
Alcohol and drugs can slow reaction time and cloud judgment. They can also affect vision, balance, and the sense of speed. An unsafe driver may drift out of a lane, follow too closely, miss stopped traffic, or brake too late.
The risk is much worse in an 18-wheeler that may weigh up to 80,000 pounds. People in smaller vehicles often suffer the most severe injuries. Our page on serious truck accident injuries in Texas explains common injuries after a major truck crash.
Truck drivers and trucking companies must follow federal safety rules. The federal alcohol and drug rules for truck drivers set these key limits:
A prescription drug is not always banned. The doctor must know the driver’s health history and say the drug will not make driving unsafe. A legal drug can still lead to fault if it makes the driver unfit to drive.
For a wider review of driver, company, cargo, and truck safety rules, see our guide to trucking regulations in Texas.
Federal law does not require a drug or alcohol test after every crash. The FMCSA post-accident testing chart lists the main times when the employer must test a driver.
| Crash event | Ticket to truck driver | Test required? |
| A person is killed | No ticket is needed | Yes |
| A person gets care away from the scene at once | Yes, for a moving traffic offense from the crash | Yes |
| A vehicle has disabling damage and must be towed | Yes, for a moving traffic offense from the crash | Yes |
| Injury or tow-away crash without the needed ticket | No | Not under this federal rule |
Testing should start as soon as possible. If an alcohol test is not done within two hours, the company must explain the delay. It must stop trying after eight hours. A required drug test must be done within 32 hours. The full rule is in 49 C.F.R. § 382.303.
A missing DOT test does not end the case. Police tests, hospital records, video, receipts, and witness accounts may still show drug or alcohol use. The reason the company failed to test may also matter.
The FMCSA Drug and Alcohol Clearinghouse is a federal record system. It stores certain drug and alcohol rule violations by CDL drivers. Employers must check it before a covered driver starts work. They must also check each current driver once a year.
The records can include positive tests, refusals, known use, and return-to-duty steps. Since November 18, 2024, state agencies must revoke a driver’s CDL rights if the driver has a prohibited status. The driver must complete the return-to-duty process before those rights are restored.
A company that skips a required check may miss a clear warning. A claim should ask what the company knew, what it should have known, and why the driver was allowed to drive.
The driver may be at fault, but the case should not stop there. Other parties may include:
Truck cases can involve several companies and insurance policies. Learn more about who may be responsible for a truck accident.
A company must do more than tell drivers not to drink or use drugs. Company fault may include:
These facts may support a claim for negligent hiring or retention of a truck driver. The proof must tie the company’s fault to the driver, the crash, and the harm.
A strong case uses records, test data, and what people saw. Useful proof may include:
Some of this proof belongs to the company or another business. A fast hold letter can require that records and data not be erased or altered.
Not by itself. The meaning of a result can depend on the drug, test type, amount, and time of use. Some drugs can be found after their short-term effects have ended.
A sound case compares the lab result with the driver’s acts, speech, balance, driving, truck data, and the time of the crash. An expert may be needed to explain what the test does and does not prove.
Sometimes. Texas calls these exemplary damages. They are not automatic. Under Texas Civil Practice and Remedies Code Chapter 41, the claimant must usually prove fraud, malice, or gross negligence by clear and convincing evidence.
A driver who knows he is badly impaired and still drives an 18-wheeler may meet that test. A trucking company may also face such a claim for its own acts. One example is sending out a driver after repeated positive tests or a known driving ban.
Severe harm alone does not prove punitive damages. The proof must meet the higher legal test. Read more about punitive damages in a Texas truck accident case.
A truck driver may not do safety-sensitive work with an alcohol level of 0.04 or higher. Other rules also ban on-duty drinking and work within four hours after drinking.
No. The rule considers death, prompt care away from the scene, tow-away damage, and whether the driver received the required traffic ticket.
Yes. The company may be at fault for the driver’s work acts and for poor hiring, testing, training, checks, or retention.
Yes. A drug can be legal but still make a driver unsafe. The facts must show how the drug, the driver’s state, and the company’s knowledge relate to the crash.
Other proof may still show drug or alcohol use. The failure to follow a required test rule may also be part of the claim.
Yes. Some family members and the estate may have claims. Our fatal truck accident claim page explains the types of claims and damages that may apply.
When drugs or alcohol may have played a role, key proof can vanish fast. The Texas Truck Accident Lawyer has handled serious truck cases for more than 40 years. We take a limited number of cases, so each client gets personal care.
Call (281) 893-0760 or contact us online for a free consultation. You pay no attorney fee unless we recover money for you.
