FMCSA Regulation §383.133 establishes clear rules for the administration of CDL skills tests, including both the Pre-Trip Inspection and the Road Test. One of the key requirements of this regulation is that interpreters are not allowed during the skills test. This means that applicants must be able to understand and respond to all verbal commands and instructions in English as provided by the examiner. Communication in any language other than English is strictly prohibited throughout the testing process.

Applicants are therefore expected to prepare in advance to understand and respond to English instructions during the test. Examiners also follow a standardized approach to give instructions clearly and consistently. By requiring the exclusive use of English, the regulation maintains the integrity of the CDL testing process, ensuring that all drivers are evaluated under the same conditions and that safety on public roads is upheld.