School bus driving is a profession with a high degree of responsibility due to the daily transportation of students. This occupation is subject to rigorous mandatory drug and alcohol screening requirements to ensure operational safety. The frequency of testing is determined by a framework of specific events and regulatory mandates that apply throughout a driver’s employment.
The Federal Regulatory Framework for Driver Safety
The primary oversight for school bus drivers operating vehicles requiring a Commercial Driver’s License (CDL) falls under the Department of Transportation (DOT). The Federal Motor Carrier Safety Administration (FMCSA) sets the specific rules governing drug and alcohol testing procedures. These requirements are codified in federal regulations (49 CFR Part 382). Compliance with these rules establishes the baseline standard that all employers of CDL drivers must follow, including school districts and transportation contractors. This regulatory structure defines the situations that trigger mandatory testing.
Specific Circumstances That Require Drug and Alcohol Testing
Pre-Employment Testing
A prospective driver must undergo a drug test with a verified negative result before performing any safety-sensitive functions, such as operating the school bus. This requirement must be satisfied before the driver’s first official day behind the wheel. The pre-employment test only screens for controlled substances; an alcohol test is not required at this stage.
Random Testing Programs
Drivers are subject to unannounced random testing throughout the year, which deters substance misuse. Selection for these tests is computer-generated to ensure a non-discretionary, valid process. The FMCSA mandates a minimum annual percentage rate for the total number of tests conducted across the driver pool. For 2025, the minimum rate for drug testing is 50% of the average number of driver positions, and the minimum rate for alcohol testing is 10%.
Post-Accident Testing
Testing is required following certain accidents involving a commercial motor vehicle operating on a public road. An alcohol test must be conducted within eight hours of the incident, and a drug test must be conducted within 32 hours. Testing is mandatory if the accident involves a human fatality, regardless of fault. Testing is also required if the driver receives a citation for a moving traffic violation and the accident involves either bodily injury requiring immediate medical treatment away from the scene or disabling damage that requires the vehicle to be towed.
Reasonable Suspicion Testing
A driver must submit to testing immediately if a trained supervisor documents observations of the driver’s behavior or physical signs suggesting drug or alcohol impairment. These observations must be specific and contemporaneous, focusing on appearance, speech, behavior, or body odor. The supervisor who makes the determination cannot be the one to administer the required alcohol test.
Return-to-Duty and Follow-Up Testing
Any driver who violates federal drug and alcohol rules must complete a return-to-duty process with a Substance Abuse Professional (SAP) before resuming safety-sensitive duties. A negative, observed return-to-duty drug test or an alcohol test below the prohibited concentration is required before the driver can return to work. Following this, the driver is subject to unannounced follow-up testing prescribed by the SAP. This testing requires a minimum of six tests in the first 12 months and can extend up to 60 months, depending on the professional’s recommendation.
Substances Included in the Testing Panel
The federal drug testing panel focuses on five specific classes of controlled substances, commonly referred to as the 5-panel test.
- Marijuana metabolites (THC)
- Cocaine
- Amphetamines
- Opioids (including confirmatory testing for codeine, morphine, heroin, hydrocodone, and oxycodone)
- Phencyclidine (PCP)
Alcohol testing is performed separately, typically using a breathalyzer, to measure the concentration of alcohol in the driver’s system.
State and Local Requirements Beyond Federal Mandates
The federal regulations serve only as the minimum testing standards; states or local school districts often implement more rigorous policies. Some jurisdictions impose testing on drivers of smaller school buses that do not require a CDL, a group not covered by the federal FMCSA mandate. A state may also choose to set a higher minimum annual percentage rate for random testing than the federal requirement. Local school districts can mandate additional types of non-DOT testing for all employees, including non-CDL drivers and attendants. The ultimate frequency of testing for a school bus driver is determined by the intersection of these federal baseline requirements and any stricter state or local policies.