DOT and FMCSA transportation training captions: CDL entry-level driver training, HazMat, ELD compliance, and WCAG 2.1 AA

The DOT/FMCSA training landscape: who produces transportation training video and why

Commercial carriers and motor carrier operators

The commercial transportation sector regulated by FMCSA encompasses approximately 550,000 active motor carriers in the United States — companies operating commercial motor vehicles (CMVs) in interstate commerce. Motor carriers range from single-owner-operator trucking operations to global logistics and freight companies employing tens of thousands of drivers. The training obligation that creates captioned video demand at motor carriers is not a single regulatory mandate but a stack of overlapping FMCSA and DOT training requirements: HOS compliance training for drivers, ELD operation training when a new ELD device is deployed, reasonable suspicion training for supervisors under 49 CFR Part 382.603, annual driver qualification file review training for safety managers, and general CDL driver orientation and onboarding training. Mid-size and large motor carriers — fleets of 50 or more power units — typically deliver driver orientation and safety training through video-based eLearning modules hosted on an LMS, both because it provides consistent training delivery and because it creates the training completion records that FMCSA requires carriers to maintain. These video-based training programmes are the principal arena where captioning is required.

Fleet safety managers at trucking companies produce or procure the majority of motor carrier training video. Third-party safety training providers serve the motor carrier market with off-the-shelf video training libraries: J.J. Keller & Associates is the largest, serving over 600,000 businesses across the transportation and manufacturing sectors with regulatory compliance training, forms, and advisory services. J.J. Keller's Encompass LMS platform is the dominant compliance LMS in transportation. NSC (National Safety Council) produces training content for fleet operators. Samsara and Motive (formerly KeepTruckin) have integrated driver training modules directly into their fleet telematics platforms — creating a category of "in-cab training" video hosted by the telematics vendor and delivered to drivers on ELD tablets during rest periods.

CDL training schools and the FMCSA Training Provider Registry

CDL training schools — commercial driving schools that prepare CDL applicants to pass the CDL skills test — are subject to the FMCSA Entry-Level Driver Training (ELDT) requirements at 49 CFR Part 380. Under the ELDT rule, which became effective February 7, 2022, CDL applicants for a Class A or Class B CDL, for a passenger (P) or school bus (S) endorsement, or for a hazardous materials (H) endorsement must complete a training programme from a provider listed on the FMCSA Training Provider Registry (TPR). The TPR is a public database of training providers that have self-certified their compliance with the ELDT curriculum standards. Registration on the TPR is a mandatory prerequisite for a training provider's instruction to qualify a CDL applicant for the CDL skills test — an applicant who completes training from a non-TPR provider is not eligible for the skills test under the ELDT rule.

The ELDT curriculum mandates specific classroom and behind-the-wheel (BTW) training content. The classroom component — which may be delivered online as eLearning — must cover specific knowledge areas defined in 49 CFR Part 380 Appendix A (for Class A CDL), Appendix B (for Class B CDL), Appendix C (for passenger endorsement), Appendix D (for school bus endorsement), and Appendix E (for the hazardous materials endorsement). These knowledge areas include Federal Motor Carrier Safety Regulations (FMCSR) content — knowledge of HOS rules, driver qualification requirements, drug and alcohol testing requirements — that is narrated with the full vocabulary of 49 CFR regulatory citations and FMCSA-specific abbreviations. The eLearning delivery of ELDT classroom content is where captioning is most consequential: a deaf or hard-of-hearing CDL applicant enrolled in an online ELDT programme at a TPR-registered school depends entirely on the caption track of each eLearning module to receive the regulatory content that the ELDT curriculum requires.

HazMat shippers, carriers, and trainers

The Pipeline and Hazardous Materials Safety Administration (PHMSA), a DOT sub-agency, regulates the transportation of hazardous materials under 49 CFR Parts 100–185 (the Hazardous Materials Regulations, or HMR). The training obligation is at 49 CFR Part 172 Subpart H (§§ 172.700–172.704): any employer who employs "hazmat employees" — employees who perform any function in the transportation of hazardous materials, including loading, unloading, blocking, bracing, labelling, marking, placarding, and driving — must provide initial and recurrent HazMat training. The training must cover general awareness and familiarization, function-specific training, safety training, security awareness training, and (for employees handling materials covered by a security plan) in-depth security training. For hazmat drivers, additional driver training on the specific hazard classes they transport is required.

HazMat training video is produced by: motor carriers that transport HazMat and must train their drivers and dock workers; shippers whose employees prepare hazmat shipments (manufacturers, chemical distributors, petroleum companies); third-party training providers (J.J. Keller dominates HazMat training content for motor carriers); community colleges with CDL programs that include the HazMat endorsement curriculum; and PHMSA itself, which produces public safety training materials. This is training content with the highest concentration of out-of-distribution STT vocabulary in the transportation sector: hazmat class designations, UN identification numbers, packing group designations, placard names and conditions of use, regulatory citations in the 49 CFR 172.XXX format, and the specialised acronyms of the hazmat response ecosystem (ERG, CHEMTREC, TIH, PIH).

DOT drug and alcohol testing programme trainers

The DOT drug and alcohol testing programme, governed by 49 CFR Part 40 (the DOT drug testing procedure regulation) and the modal agency rules (FMCSA Part 382 for commercial vehicle drivers, FTA Part 655 for transit, FAA Part 120 for aviation, FRA Part 219 for railroads, PHMSA Part 199 for pipeline workers, USCG Part 4 for maritime), requires that supervisors who supervise safety-sensitive function employees undergo specific training before they can require a drug or alcohol test based on reasonable suspicion. Under 49 CFR Part 382.603, FMCSA requires supervisors of CDL drivers to complete at least 60 minutes of training on controlled substances and at least 60 minutes of training on alcohol misuse. This supervisor reasonable suspicion training is widely delivered as video-based eLearning — the 60-minute minimum makes it a natural fit for a single video module or series. It is one of the most consistently captioned transportation training categories, because carriers have historically treated it as a completion-trackable compliance training requirement delivered through their LMS. The captioning quality, however, varies enormously: reasonable suspicion training narrated with DOT testing vocabulary (MRO, SAP, RTD, ODAPC, Part 40, Part 382, 49 CFR citations) requires a transportation-specific vocabulary layer that generic auto-captions do not provide.

Why auto-captions fail catastrophically on transportation training video

CDL and driver licensing vocabulary

The CDL licensing vocabulary in ELDT and motor carrier training content represents one of the most distinctive abbreviation-collision failure profiles in any regulated industry training category. It combines single-letter codes (CDL classes, CDL endorsements), multi-letter acronyms (CMV, GVWR, GCWR, CLP, ELDT, TPR, BTW), and regulatory term-of-art phrases (Commercial Learner's Permit, Entry-Level Driver Training, Training Provider Registry) that are narrated conversationally at production speed by trainers who assume familiarity with the vocabulary. Generic STT has no training data for this vocabulary profile and fails across its entire range.

• CDL Classes (A, B, C): the three CDL classes are defined by the GVWR of the vehicles they authorise the holder to operate. Class A covers combination vehicles with a GCWR over 26,000 lbs where the towed unit exceeds 10,000 lbs GVWR — the typical over-the-road tractor-trailer class. Class B covers single vehicles over 26,000 lbs GVWR and any vehicle towing a unit not exceeding 10,000 lbs GVWR — buses, straight trucks, dump trucks. Class C covers vehicles not falling in Class A or B that are designed to transport 16 or more passengers (including the driver) or that are used to transport hazardous materials requiring placards. Narrated as "Class A," "Class B," "Class C" — the letter is the key information. STT: "Class A" (correct), "class-a" (lowercase), "classy" (phonetic collapse — "Class A" → "classy" is a documented STT false match on fast narration), "Class 8" (numeric substitution — Class 8 is an unrelated truck weight classification used in the trucking industry, and STT may substitute the numeric class for the alphabetic CDL class in a transportation-vocabulary context).
• CDL Endorsements (H, N, P, S, T, X): the six CDL endorsement letters are added to the CDL to authorise specific vehicle types or cargo categories. H = hazardous materials (requires TSA security threat assessment), N = tank vehicles (cargo tanks and portable tanks), P = passenger (bus), S = school bus, T = double/triple trailers, X = combination of tank vehicles and hazardous materials (tank + H). These are narrated as single letters: "an H endorsement," "the N endorsement," "T endorsement for doubles and triples." STT failure modes: single letter endorsements are among the most unreliable elements in any STT output. "H endorsement" → "age endorsement," "aitch endorsement," "H. endorsement"; "N endorsement" → "and endorsement" (the letter N and the conjunction "and" are phonetically identical in most speech, and STT context-weights toward the far more frequent word); "P endorsement" → "pee endorsement," "P. endorsement"; "T endorsement" → "tea endorsement," "T. endorsement"; "S endorsement" → "yes endorsement," "asked endorsement" (phonetic collapse on "es" → "yes" or "as" in context). The X endorsement — combination tank plus HazMat — is narrated as "X endorsement" or "combined tank and HazMat endorsement"; STT: "X endorsement" (correct), "ex endorsement" (renders the letter as the word "ex"), "cross endorsement."
• GVWR (Gross Vehicle Weight Rating): the maximum weight a vehicle is designed to carry as specified by the manufacturer. Defined threshold for CDL Class A and B requirements. Narrated as "G-V-W-R" (four letters spelled out) or "the GVWR." STT: "GVWR" (correct), "G V W R" (letter-spaced), "G.V.W.R." (with periods), "driver" (extreme phonetic collapse — four-letter acronym reduced to a common word), "GVWRA" (extra letter appended). The GVWR threshold — "vehicles with a GVWR over twenty-six thousand pounds" — must be accurately transcribed because it is the statutory definition of when CDL requirements apply.
• GCWR (Gross Combination Weight Rating): the GVWR of the power unit plus the GVWR of the towed unit — the combined weight rating for a tractor-trailer combination. Narrated as "G-C-W-R" (four letters). STT: "GCWR" (correct), "GCW are" (phonetic rendering with the letter R as a word), "G C W R" (letter-spaced). GCWR and GVWR appear in the same ELDT classroom modules defining Class A CDL requirements, so consistent and distinct rendering of both is required.
• CMV (Commercial Motor Vehicle): the defined term under 49 CFR Part 390.5 — a vehicle used in interstate commerce to transport passengers or property, meeting specified GVWR, GCWR, or capacity thresholds. Narrated as "C-M-V" or "CMV." STT: "CMV" (correct), "C M V" (letter-spaced), "see em vee" (phonetic), "CMVs" (plural — correctly handled), "CMV" occasionally rendered as "CNN" or other three-letter media brand in contexts where STT context-weights toward news vocabulary. In HOS training, "operating a CMV" is narrated dozens of times; inconsistent CMV rendering creates a noisy, inconsistent caption track across a full ELDT module.
• ELDT (Entry-Level Driver Training): the 49 CFR Part 380 mandatory training programme for CDL applicants. Narrated as "E-L-D-T" (four letters, often pronounced as a word — "eldt" rhyming with "belt"). STT: "ELDT" (correct), "E L D T" (letter-spaced), "eldt" (lowercase word form — looks like a mis-spelled archaic English word), "felt" (phonetic false match — the final unvoiced stop consonants of "eldt" collapse to "felt" in fast speech), "belted" (extended phonetic false match). "ELDT requirements," rendered as "felt requirements" or "belted requirements," loses the regulatory programme name entirely.
• TPR (Training Provider Registry): the FMCSA database of ELDT-approved training providers. Narrated as "T-P-R" (three letters) or "the TPR" (as a word — "tee-pee-are"). STT: "TPR" (correct), "T P R" (letter-spaced), "teepee are" (phonetic rendering that creates a visual association with a tipi), "TPR" occasionally rendered as "the PR" (dropping the T), "T.P.R." (with periods). "Listed on the TPR" rendered as "listed on the teepee are" is not recognisable as a regulatory database reference.
• CLP (Commercial Learner's Permit): the permit issued before the CDL skills test, authorising operation of a CMV under the supervision of a CDL holder. Narrated as "C-L-P" or "the CLP." STT: "CLP" (correct), "clap" (phonetic — three-letter acronym collapses to a one-syllable word with shared consonants), "C L P" (letter-spaced), "clip" (phonetic variant). In ELDT training, the CLP is required before BTW training can begin; "must hold a CLP before beginning BTW training" rendered as "must hold a clap before beginning behind-the-wheel training" loses the permit designation.
• BTW (Behind-the-Wheel): the practical, on-vehicle training component of ELDT, as distinct from the classroom (theoretical knowledge) component. Narrated as "B-T-W" or "BTW." STT: "BTW" (correct — but this is also the standard abbreviation for "by the way" in text messaging, creating a register collision), "B T W" (letter-spaced), "behind-the-wheel" (expanded form — correctly rendered when the full phrase is narrated). In a ELDT context, "BTW training hours" should never be rendered as "by the way training hours," but the text-message connotation of BTW creates this false match in STT systems trained on informal text.

Hours of Service and ELD vocabulary

FMCSA's Hours of Service (HOS) regulations at 49 CFR Part 395 govern the maximum hours CDL drivers may drive and the minimum off-duty rest they must take. The ELD mandate at 49 CFR Part 395.8 and 395.15 requires most carriers to use Electronic Logging Devices that automatically record driving time. HOS and ELD training content — explaining the rules to drivers and teaching them how to use their ELD — uses a vocabulary that is almost entirely absent from general STT training data: specific hour limits as regulatory thresholds, the exact names of HOS rule provisions, ELD technical terms, and ELD vendor product-specific vocabulary.

• HOS (Hours of Service): narrated as "H-O-S" (three letters) or "the HOS rules" (often pronounced "hoss" — rhyming with "boss"). STT: "HOS" (correct), "hoss" (phonetic — an informal word for a large, strong horse or person, used colloquially in the South), "H O S" (letter-spaced). "The 11-hour HOS driving limit" → "the eleven-hour hoss driving limit" converts a regulatory acronym into a colloquialism.
• ELD (Electronic Logging Device): narrated as "E-L-D" (three letters) or "the ELD" (sometimes pronounced "eld" — rhyming with "held"). STT: "ELD" (correct), "eld" (lowercase — an archaic English suffix), "E L D" (letter-spaced), "held" (phonetic false match — "eld" → "held" is a common one-substitution phonetic collapse). "Your ELD must record driving time" rendered as "your held must record driving time" destroys the sentence meaning.
• DVIR (Driver Vehicle Inspection Report): the daily pre-trip and post-trip inspection report required by 49 CFR Part 396. Narrated as "D-V-I-R" (four letters). STT: "DVIR" (correct), "D V I R" (letter-spaced), "driver" (phonetic collapse — four-letter acronym with "D" and "R" in the right positions maps to the common word "driver," a particularly ironic false match in CDL driver training), "DIV R" (reordered letters). "Complete your DVIR before each trip" rendered as "complete your driver before each trip" is syntactically plausible and therefore undetectable by basic caption quality checks.
• RODS (Records of Duty Status): the paper logbook entries that pre-dated ELD electronic recording. Still referenced in legacy training and in HOS training that covers exemptions from the ELD mandate. Narrated as "R-O-D-S" or "RODS" (pronounced "rodz"). STT: "RODS" (correct), "roads" (phonetic false match — "rodz" → "roads" is an extremely common one-substitution error in fast speech), "rods" (lowercase — metal fasteners, not duty status records). "Maintaining paper RODS during an ELD malfunction" → "maintaining paper roads during an ELD malfunction" creates a sentence about transportation infrastructure, not compliance documentation.
• AOBRD (Automatic On-Board Recording Device): the predecessor technology to ELD, which was compliant with earlier FMCSA recording rules before the ELD mandate took full effect. Legacy training content produced before the ELD transition (pre-2019) and training that explains the AOBRD-to-ELD transition still narrates "AOBRD." Narrated as "A-O-B-R-D" (five letters) or "ay-oh-berd." STT: "AOBRD" (correct), "A O B R D" (letter-spaced), "a obeyed" (phonetic collapse), "a over D" (partial phonetic reconstruction). "Carriers that used AOBRD systems prior to the ELD mandate" → "carriers that used a obeyed systems prior to the ELD mandate" loses the technology category name.
• Personal Conveyance (PC): the FMCSA-permitted use of a CMV for personal use when off-duty, which does not count against HOS driving time. Annotated on ELDs as a special duty status. Narrated as "personal conveyance" or "P-C." STT: "personal conveyance" (correct — the full phrase is generally rendered well), "P.C." (with periods — fine), "P C" (letter-spaced). The specific ELD annotation — drivers must select "Personal Conveyance" in their ELD — requires the exact term to be transcribed; training that teaches drivers how to annotate their ELD must use the exact vocabulary the ELD interface uses.
• Yard Moves (YM): the FMCSA-permitted annotation for on-property CMV movement within a terminal, yard, or facility that does not constitute driving on a public road and is not counted against HOS driving time. Annotated on ELDs as "Yard Moves." STT: "Yard Moves" (correct), "yard moves" (correct lowercase), "yardmore's" (phonetic collapse at speed). ELD training that teaches drivers when Yard Moves annotation is appropriate must accurately render the term as it appears in the ELD interface.
• 34-hour restart: the FMCSA provision under 49 CFR Part 395 that allows a driver to restart their 60/70-hour on-duty clock after 34 consecutive hours off duty. Narrated as "thirty-four hour restart" or "34-hour restart." STT: "34-hour restart" (correct), "thirty-four hour restart" (correct word form), "34 hour restart" (without hyphen — minor variant), "34 hour re-start" (hyphenated the second syllable). The 34-hour restart provision has been revised multiple times (including restrictions on when it can be used, which were then removed), so training that references the restart provision with any qualifying conditions must narrate those conditions accurately.
• Sleeper Berth provision: the HOS provision allowing drivers operating vehicles equipped with sleeper berths to split their required off-duty rest into two periods: at least 7 consecutive hours in the sleeper berth and a separate period of at least 2 consecutive hours either off duty or in the sleeper berth. "Sleeper berth" is narrated as two words. STT: "sleeper berth" (correct), "sleeper birth" (phonetic — "berth" and "birth" are homophones, and "birth" is the far more common word), "sleeper berth" vs "sleeper birth" inconsistency within a single training video is the most common HOS vocabulary error in transportation training captions and is systematically undetectable by automated quality checks that cannot distinguish between homophones.
• ELD Malfunction Codes: FMCSA at 49 CFR Part 395.34 defines seven ELD malfunction diagnostic codes, each identified by a single letter: P (power compliance malfunction), E (engine synchronisation malfunction), T (timing compliance malfunction), L (positioning/GPS compliance malfunction), R (data recording compliance malfunction), S (data transfer compliance malfunction), O (other ELD detected malfunction). Drivers must know these codes to understand what malfunction indicator their ELD is displaying and what the compliance consequence is. Narrated as single letters: "a P malfunction," "an E malfunction," "an L malfunction." STT: single-letter malfunction code designations are among the most unreliable STT outputs possible — any single letter in conversational context is subject to near-total phonetic collapse. "A P malfunction means your ELD has lost power compliance" → "a pee malfunction means your held has lost power compliance" renders the code as a bodily function word and the device as a past-tense verb. ELD malfunction training that relies on accurate single-letter code rendering cannot use generic STT captions.

FMCSA Safety Programme vocabulary

The FMCSA administers the Compliance, Safety, Accountability (CSA) programme, which uses the Safety Measurement System (SMS) to assess carrier and driver safety performance based on roadside inspection and crash data. Motor carrier safety managers receive training on how to monitor their SMS scores, understand their BASIC (Behavior Analysis and Safety Improvement Categories) standings, and respond to SMS alerts. This training vocabulary is highly specific to the FMCSA safety programme infrastructure and has the additional failure mode that several of its abbreviations are common English words in other contexts.

• SMS (Safety Measurement System): FMCSA's carrier scoring system that calculates safety performance percentile rankings for motor carriers based on data from roadside inspections, crashes, and violations. Narrated as "S-M-S" (three letters) or "the SMS." STT: "SMS" (correct in transportation context), "text messages" (catastrophic false match — in general STT training data, "SMS" is overwhelmingly associated with Short Message Service, and a transportation training video that narrates "your SMS score" may be transcribed as "your text message score"), "S M S" (letter-spaced). In FMCSA safety manager training, "improving your SMS BASIC scores" rendered as "improving your text message BASIC scores" destroys the sentence's regulatory meaning.
• BASIC (Behavior Analysis and Safety Improvement Categories): the seven measurement categories of the FMCSA SMS: Unsafe Driving, Hours-of-Service Compliance, Driver Fitness, Controlled Substances/Alcohol, Vehicle Maintenance, Hazardous Materials, and Crash Indicator. "BASIC" in this context is an acronym that happens to spell a common English word. STT: "BASIC" (correct — and this is actually a common STT output because the word "basic" is high-frequency), but the acronym-vs-word distinction is lost. Training that references "your Hazardous Materials BASIC" means the HazMat measurement category, not something that is generic or elementary. The capitalisation distinction is invisible in audio — STT that renders "BASIC" with incorrect contextual meaning ("the most basic requirement") rather than the FMCSA category name requires a vocabulary layer to maintain the term's regulatory sense.
• CSA (Compliance, Safety, Accountability): the FMCSA programme framework within which SMS operates. Narrated as "C-S-A" (three letters). STT: "CSA" (correct), "C S A" (letter-spaced), "CSAs" (plural), "see-es-ay" (phonetic). CSA is a reasonably well-handled abbreviation in STT because "CSA" appears in multiple institutional contexts (Community Supported Agriculture, Confederate States of America, Canadian Standards Association) and the letters are non-colliding; the FMCSA-specific meaning requires context.
• ISS (Inspection Selection System): the FMCSA/CVSA system that recommends to roadside inspectors whether to conduct a full inspection of a passing CMV, based on the carrier's and driver's safety records in SMS. Narrated as "I-S-S" (three letters) or "the ISS." STT: "ISS" (correct), "I S S" (letter-spaced), "is" (phonetic collapse — three-letter acronym → two-letter word), "the ISS" occasionally → "the is" (grammatically incoherent but phonetically plausible).
• DataQ (FMCSA's data correction request system): the FMCSA online system by which carriers and drivers can challenge inaccurate inspection report data, crash records, or other safety data that affects their SMS scores. Narrated as "DataQ" or "data-queue." STT: "DataQ" (correct), "data queue" (phonetic expansion — technically the correct expansion but rendered as two words rather than the branded system name), "data cue" (homophone — "queue" and "cue" are homophones, and "data cue" looks like a cinematic or theatrical reference), "data key" (phonetic variant). In training that instructs motor carriers on how to challenge inaccurate SMS data, "file a DataQ request" → "file a data cue request" loses the system name.
• USDOT Number: the identifying number issued by FMCSA to each commercial motor carrier or registrant, used across DOT filings and roadside inspection data. Narrated as "U-S-D-O-T number" or "USDOT number." STT: "USDOT number" (correct), "U.S. DOT number" (with periods — equally acceptable), "US dot number" (lowercase — loses the agency acronym context), "USDA number" (letter-substitution — USDA is a similar-sounding government agency acronym that appears in STT training data).
• MC Number (Motor Carrier Authority Number): the operating authority number issued by FMCSA to for-hire motor carriers. Narrated as "M-C number" or "your MC number." STT: "MC number" (correct), "M C number" (letter-spaced), "em-see number" (phonetic), "MC" occasionally rendered as "emcee" (the pronunciation identical to "MC" but referring to master of ceremonies in entertainment contexts — "your emcee number" is a strikingly incongruous false match in a motor carrier training context).
• IFTA (International Fuel Tax Agreement): the agreement among US states and Canadian provinces simplifying the reporting of fuel taxes by motor carriers operating in multiple jurisdictions. Carriers with IFTA credentials file quarterly fuel tax reports. Narrated as "I-F-T-A" (four letters) or "IFTA" (as a word — "if-ta"). STT: "IFTA" (correct), "Ifta" (capitalisation variant), "if-ta" (phonetic — sounds like a conditional phrase fragment), "I F T A" (letter-spaced). "Your IFTA decals must be displayed" → "your if-ta decals must be displayed" loses the regulatory programme name.
• IRP (International Registration Plan): the agreement among US states and Canadian provinces for proportional registration of commercial vehicles that travel in multiple states. Works alongside IFTA for multi-state carrier compliance. Narrated as "I-R-P" (three letters). STT: "IRP" (correct), "I R P" (letter-spaced), "irp" (lowercase — meaningless word). IRP appears in carrier orientation training for new fleet managers learning multi-state compliance requirements.
• PrePass (weigh station bypass system): a transponder-based system that allows pre-screened motor carriers to bypass weigh stations without stopping, based on a real-time safety and compliance check. "PrePass" is a branded proper name. STT: "PrePass" (correct), "pre-pass" (hyphenated), "pre pass" (two words), "pre-past" (phonetic variant — "pass" → "past" in fast speech), "free pass" (phonetic false match — "pre" → "free" is a one-consonant substitution that produces an entirely different phrase). "Participating carriers receive a PrePass transponder" → "participating carriers receive a free pass transponder" changes the sentence meaning from a specific technology system to a colloquial benefit.
• Drivewyze (competing weigh station bypass): an app-based weigh station bypass service competing with PrePass. "Drivewyze" is a branded proper name spelled with a non-standard "wyze" suffix. STT: "Drivewyze" (correct), "drive wise" (phonetic — the most common false match, because "wyze" is phonetically "wise" and the brand intentionally echoes the phrase "drive wise"), "Drivewise" (without the y). In training that discusses weigh station bypass options, "Drivewyze" consistently appearing as "drive wise" loses the proper name of the competing bypass service.

HazMat and PHMSA vocabulary

Hazardous materials transportation training has the deepest regulatory vocabulary of any FMCSA training category. The Hazardous Materials Regulations (HMR) at 49 CFR Parts 100–185 define a complete classification, labelling, marking, placarding, and documentation system for hazardous materials in commerce. HazMat training video — which must cover this system comprehensively for covered employees — narrates hazard class designations, UN identification numbers, regulatory citations, emergency response vocabulary, and shipping documentation vocabulary in a sustained, technical register that is comprehensively out-of-distribution for generic STT.

• HazMat Class designations: the nine hazard classes with their divisions (Class 1 Explosives Divisions 1.1 through 1.6; Class 2 Gases with Divisions 2.1 Flammable, 2.2 Non-Flammable Non-Toxic, 2.3 Toxic; Class 3 Flammable/Combustible Liquids; Class 4 Flammable Solids Divisions 4.1, 4.2, 4.3; Class 5 Oxidizing Substances and Organic Peroxides Divisions 5.1, 5.2; Class 6 Toxic/Infectious Divisions 6.1, 6.2; Class 7 Radioactive; Class 8 Corrosive; Class 9 Miscellaneous) are narrated as ordinal designations ("Class 3 flammable liquid," "Division 2.3 toxic gas"). STT: "Class 3" (correct), "class three" (word form — correct variant), "Class 3." (with spurious period — creates sentence-end rendering). The division decimal format — "Division 2.3" or "Division one-point-three" — has the same decimal-period STT failure mode as 49 CFR citation numerals: some STT systems render the decimal as a hyphen ("Division 2-3") or omit it entirely ("Division 23"), losing the specificity of the division designation.
• UN numbers (UN identification numbers): the four-digit UN hazard identification numbers (UN1093, UN1203 for gasoline, UN3480 for lithium-ion batteries, UN1017 for chlorine) that must appear on shipping papers and, for bulk quantities, on placards. Narrated as "U-N" followed by four digits: "U-N one-two-oh-three," "UN 1203." STT failure modes: "U-N" → "union" (phonetic — "you-en" → "union" is a documented and extremely common false match for two-letter federal programme acronyms followed by numerals); "UN1203" → "union 1203" (full phonetic expansion of the letter prefix). "UN numbers" → "union numbers" removes the regulatory identification system and replaces it with a labour organisation reference. "The material must display its UN number on the placard" → "the material must display its union number on the placard" is both grammatically plausible and semantically incorrect in a HazMat placard training context.
• ERG (Emergency Response Guidebook): the PHMSA/Transport Canada publication that first responders and hazmat emergency personnel use to identify hazardous materials and determine initial protective action distances. Narrated as "E-R-G" (three letters) or "the ERG." STT: "ERG" (correct), "erg" (lowercase — a unit of energy in the CGS measurement system, making this a false match with a real English word), "E R G" (letter-spaced), "urge" (phonetic — "erg" → "urge" is a near-homophone false match). "Consult the ERG for isolation distances" → "consult the erg for isolation distances" renders the emergency reference guide as a unit of energy measurement.
• TIH (Toxic-by-Inhalation Hazard): the designation for materials that are hazardous when inhaled, triggering specific placard, routing, and handling requirements under the HMR. Narrated as "T-I-H" (three letters) or "TIH." STT: "TIH" (correct), "T I H" (letter-spaced), "tie-H" or "tie-aitch" (phonetic), "tie" (extreme collapse — the first letter produces the highest-frequency similar-sounding word). "TIH materials require a 27-mile routing radius" → "tie materials require a 27-mile routing radius" is phonetically plausible but semantically nonsensical.
• PIH (Poison-by-Inhalation): the legacy term for TIH, still used in some training content. Narrated as "P-I-H" (three letters). STT: "PIH" (correct), "pie" (phonetic false match — "pee-eye-aitch" at speed → "pie" is perhaps the most widely documented single-abbreviation STT false match in hazmat training, consistently flagged in HazMat training QA reviews), "P I H" (letter-spaced). "PIH materials include chlorine and ammonia" → "pie materials include chlorine and ammonia" is perhaps the most absurd vocabulary failure in transportation training captions — and it occurs in literally every auto-captioned HazMat training video that narrates this abbreviation.
• CHEMTREC (Chemical Transportation Emergency Center): the American Chemistry Council's 24-hour emergency response centre that provides chemical safety information and emergency response guidance during hazmat incidents. Narrated as "CHEM-trec" or "CHEMTREC." STT: "CHEMTREC" (correct), "chem track" (phonetic — "CHEMTREC" → "chem track" because the "trec" syllable maps to the high-frequency word "track" + the STT drops the final consonant), "chem trek" (alternative phonetic — maps "trec" to the proper name "Trek"), "Kem-trec" (alternate capitalisation). HazMat training instructs drivers to call CHEMTREC in the event of a hazmat incident; "call chem track" or "call chem trek" in a training caption fails to communicate the specific emergency contact name that the driver needs to know.
• Packing Groups I, II, III: the HMR classification for the degree of hazard a material presents within a hazard class: Packing Group I (great danger), Packing Group II (medium danger), Packing Group III (minor danger). Narrated as "Packing Group One," "Packing Group Two," "Packing Group Three" or as "Packing Group Roman-numeral-I/II/III." STT: "Packing Group I" (correct — if the narrator uses "one" the STT typically renders it numerically, but if Roman numerals are used in narration it may render as "Packing Group eye" for "I"), "Packing Group II" → "Packing Group two" (correct word form but inconsistent with the Roman numeral format used in the HMR), "Packing Group III" → "Packing Group three" (same). Consistent rendering of packing group designations — matching the Roman numeral format of the HMR — requires a vocabulary layer.
• SDS (Safety Data Sheet): the OSHA/GHS-required chemical hazard information sheet. In HazMat transportation training, SDSs are referenced alongside shipping papers because the SDS provides the shipper with the information needed to prepare the shipping description. STT renders "SDS" correctly in most cases, but the same compound chemical-name failure mode that affects OSHA HazCom training (see the HazCom chemical name captions reference) applies in HazMat transportation training: the SDS-referenced chemical names (IUPAC names, CAS numbers, UN proper shipping names) all fail in generic STT.
• NMFC (National Motor Freight Classification): the freight classification system developed by the National Motor Freight Traffic Association that assigns a class (Class 50 through Class 500) to commodities for less-than-truckload (LTL) freight shipping. Referenced in intermodal and general freight training. Narrated as "N-M-F-C." STT: "NMFC" (correct), "N M F C" (letter-spaced), "em-ef-see" (partial phonetic). In LTL freight training that references commodity classes, "the NMFC class determines your freight rate" → "the em-ef-see class determines your freight rate" is unhelpful.

ELD and fleet technology vocabulary

ELD training content has two distinct vocabulary failure modes: the FMCSA regulatory vocabulary for ELD requirements (addressed above under HOS vocabulary) and the ELD vendor product-specific vocabulary for specific ELD platforms. Motor carriers deploy a specific ELD vendor's device and software, and their driver training is product-specific: it teaches drivers how to use their specific ELD — the menu structures, the annotation options, the malfunction response procedures — all narrated using the vendor's proprietary product names and interface terminology.

• Samsara: a fleet management and ELD platform. The brand name "Samsara" (from Sanskrit — the cycle of death and rebirth) is completely out-of-distribution for English-language STT. STT: "Samsara" (correct when the STT is exposed to the word), "Samsung" (brand-name substitution — the shared initial syllable "Sam-" leads STT toward the higher-frequency Samsung brand), "sam-sara" (phonetic hyphenation), "samsera" (phonetic mis-spelling). Driver orientation training at a carrier using Samsara ELDs will reference "your Samsara app" and "the Samsara ELD" throughout — "the Samsung ELD" in every caption instance is a pervasive branding error with the second-largest ELD provider in the US market.
• Motive (formerly KeepTruckin): the ELD vendor that rebranded from KeepTruckin to Motive in 2022. Training content produced before the rebrand uses "KeepTruckin"; training produced after uses "Motive"; some training produced during the transition period uses both. "KeepTruckin" → "keep truckin'" (correct informal form), "keep trucking" (expanded), "keep truckin" (without apostrophe). "Motive" → "motive" (correct as a common English word — this is actually one case where the vendor name is a common word and will be correctly rendered by STT but without the proper-noun capitalisation). The legacy content problem: a motor carrier whose driver training video references "KeepTruckin" and whose drivers now use "Motive" ELDs will have a vocabulary collision in the caption track that the driver may not recognise as the same product.
• Omnitracs: a fleet management and ELD platform serving large carriers. "Omnitracs" → STT: "Omnitrax" (phonetic — the "-tracs" ending maps to the common "-trax" brand suffix), "Omni tracks" (two words with standard spelling), "Omnitrack" (singular). In large-carrier ELD training, "log in to your Omnitracs tablet" → "log in to your Omni tracks tablet" loses the specific product name.
• PeopleNet: a fleet management platform (now part of Trimble) used by large carriers. "PeopleNet" → STT: "people net" (two words — common), "PeopleNet" (correct), "people net" (correct lowercase two-word form), "people.net" (domain-name rendering).
• Geotab: a fleet management and GPS tracking platform. "Geotab" → STT: "geo tab" (two words), "Geo Tab" (capitalised two words), "Geotab" (correct). "Geotab" is relatively well-handled by STT because the component words "geo" and "tab" are common, but the compound rendering is inconsistent.
• ECM/ECU (Engine Control Module/Unit): the vehicle's on-board computer from which the ELD draws engine data (speed, RPM, power status) to automatically record driving status. Narrated as "E-C-M" or "E-C-U" or "the ECM/ECU." STT: "ECM" (correct), "E C M" (letter-spaced), "E.C.M." (with periods), "E C U" (letter-spaced), "Ecuador" (extreme phonetic false match on "E-C-U" in some STT systems that context-weight toward country names for three-letter sequences). In ELD technical training, "the ELD connects to the vehicle's ECM" → "the ELD connects to the vehicle's Ecuador" is not a recoverable caption error.

Drug and alcohol testing vocabulary

DOT drug and alcohol testing training — both the 49 CFR Part 382.603 supervisor reasonable suspicion training and the broader Part 40 testing procedure training for Designated Employer Representatives (DERs) and safety personnel — uses a regulatory vocabulary drawn from the DOT drug and alcohol testing regulatory framework. This vocabulary combines role abbreviations, programme names, regulatory citations, and procedure-specific terminology that generic STT has essentially no exposure to.

• MRO (Medical Review Officer): the licensed physician who reviews laboratory drug test results for DOT-regulated testing, contacts drivers with confirmed positive results, and makes medical explanations determinations. Narrated as "M-R-O" (three letters) or "the MRO." STT: "MRO" (correct), "M R O" (letter-spaced), "em-are-oh" (phonetic), "mro" (lowercase). In supervisor training, "results are sent to the MRO" → "results are sent to the em-are-oh" loses the role designation; "results are sent to the M-R-O" (letter-spaced) is correct but inconsistent with the single-token acronym standard.
• SAP (Substance Abuse Professional): the credentialed professional who evaluates employees who have violated DOT drug and alcohol regulations and recommends education, treatment, and follow-up testing. Narrated as "S-A-P" (three letters) or "the SAP" (as a word — "sap"). STT: "SAP" (correct), "sap" (lowercase — the tree fluid or informal term for a foolish person; both common English words that STT may default to in a context where the abbreviation is not flagged as a proper noun), "S A P" (letter-spaced). "Contact a SAP for evaluation" → "contact a sap for evaluation" renders a regulatory credentialed role as an insult.
• RTD (Return-to-Duty): the DOT testing requirement for employees who violated a drug or alcohol regulation and have completed the SAP-recommended programme — a return-to-duty test that must be negative before the employee can resume safety-sensitive functions, followed by a follow-up testing plan. Narrated as "R-T-D" (three letters) or "RTD" (as a word — "ar-tee-dee"). STT: "RTD" (correct), "R T D" (letter-spaced), "arty dee" (phonetic), "artsy" (phonetic collapse). "Pass the RTD test before resuming driving duties" → "pass the artsy test before resuming driving duties" is not recoverable as a regulatory testing requirement.
• ODAPC (Office of Drug and Alcohol Policy and Compliance): the DOT office that administers the Federal drug and alcohol testing programme and provides guidance on Part 40 compliance. Narrated as "O-D-A-P-C" (five letters) or "oh-dap-see." STT: "ODAPC" (correct), "oh-dap-see" (phonetic rendering of the pronunciation — correct acoustically but rendered as a phonetic string rather than the acronym), "O D A P C" (letter-spaced), "odapsy" (collapsed phonetic). ODAPC publishes guidance documents and Q&As on Part 40 compliance; training that references ODAPC guidance must transcribe the office name accurately.
• DFWP (Drug-Free Workplace Program): the employer programme, recognised by carriers and transportation companies, for maintaining a drug-free work environment. Often referenced in drug and alcohol programme training. Narrated as "D-F-W-P" (four letters). STT: "DFWP" (correct), "D F W P" (letter-spaced), "D.F.W.P." (with periods), "def-whip" (phonetic — creative but incorrect). "Our DFWP policy requires testing upon reasonable suspicion" → "our def-whip policy" is not recognisable as a programme designation.
• 49 CFR Part 40 and Part 382 citations: the two core regulatory citations for DOT drug and alcohol testing. "Part 40" is the DOT-wide drug testing procedure regulation; "Part 382" is the FMCSA-specific rule applying Part 40 to CDL drivers. Narrated as "forty CFR Part forty" (for 49 CFR Part 40) — note the identical number for the title and the part, which narrators sometimes emphasise — and "forty-nine CFR Part three-eighty-two." STT citation failures mirror the same decimal and format inconsistencies documented for 49 CFR Part 380 and 49 CFR Part 172: "49 CFR Part 40" → "49 C.F.R. Part 40," "49 CFR part forty," "49 CFR Part 40" (correct), "49 CFR § 40" (with section symbol).

ADA and federal accessibility obligations for transportation training

ADA Title I — employer accommodation for motor carriers and CDL schools

The Americans with Disabilities Act Title I applies to employers with 15 or more employees and requires that employers provide reasonable accommodations to qualified individuals with disabilities, including hearing disabilities. Motor carriers with 15 or more employees — which covers virtually every carrier of commercial significance, from regional LTL carriers to the largest truckload fleets — are subject to ADA Title I. CDL training schools that employ 15 or more staff members are also covered. The ADA Title I accommodation obligation extends directly to training: an employer who provides training to employees must make that training accessible to employees with hearing disabilities. For motor carriers that deliver driver orientation, HOS compliance, ELD operation, and reasonable suspicion supervisor training through video-based eLearning modules, ADA Title I requires that the caption track of each video module accurately convey the audio content.

The specific workforce categories with hearing disabilities who receive transportation training video include: hearing-impaired CDL drivers (who receive ELD training, HOS training, and driver orientation from their carrier); hearing-impaired fleet safety managers and dispatchers (who receive reasonable suspicion supervisor training, SMS/BASIC monitoring training, and FMCSR compliance training); hearing-impaired warehouse and dock workers at carrier terminals (who receive HazMat awareness training, dock safety training, and OSHA-required training with transportation vocabulary overlay); and hearing-impaired CDL applicants at CDL schools (who are enrolled in ELDT programmes and require accurate captions on all online ELDT classroom modules).

The FMCSA's own medical qualification standards at 49 CFR § 391.41(b)(11) impose a hearing standard for interstate CDL drivers: the driver must perceive a forced whispered voice in the better ear at not less than 5 feet with or without the use of a hearing aid. The FMCSA does, however, maintain a hearing exemption programme (regulated under 49 CFR Part 381) that allows individual drivers who do not meet the hearing standard to obtain a hearing exemption for interstate commercial operation. Carriers with drivers operating under hearing exemptions have an especially acute ADA Title I obligation: these drivers are explicitly working under a federal exemption for their hearing disability in a safety-sensitive role, and their employer-provided training must be accessible through accurate captions.

ADA Title II — state DOTs and public transit agencies

State departments of transportation and public transit agencies are state and local government entities subject to ADA Title II, which prohibits disability discrimination by public entities and requires that programmes, services, and activities be accessible. For transportation training contexts:

• State DOT CDL training video: many state DOTs produce CDL skills test preparation materials, including video walkthroughs of the CDL pre-trip inspection and basic control skills test elements. These videos are distributed publicly to CDL applicants preparing for their state skills test. As public entity content, these videos are subject to ADA Title II and, post-April 24, 2026, to the hard WCAG 2.1 AA deadline for state and local government digital content. CDL skills test preparation videos have particularly high vocabulary failure rates in generic STT because they systematically narrate the CDL vocabulary (GVWR, Class A, endorsement codes, BTW, DVIR) that generic STT fails on.
• Public transit agencies: municipal and regional transit systems (bus, rail, paratransit) that train bus drivers, train operators, and paratransit drivers. Transit operator training — which covers transit agency safety rules, ADA paratransit service requirements, fare collection procedures, and emergency response procedures — has its own regulatory vocabulary (FTA Part 655 drug testing for transit operators, FTA Section 504, ADA paratransit service requirements) overlapping with DOT transportation vocabulary. Post-April 2026, public transit agency training video distributed through agency websites or learning management systems must meet WCAG 2.1 AA.
• WCAG 2.1 AA hard deadline: the Department of Justice's April 24, 2024 rule under ADA Title II, setting WCAG 2.1 Level AA as the technical standard for web content and mobile applications of state and local government entities, with compliance deadlines of April 24, 2026 for entities with populations over 50,000 and April 26, 2027 for smaller entities. State DOTs in every state are covered by the April 2026 deadline. Pre-recorded audio-visual content must meet WCAG 2.1 AA Success Criterion 1.2.2 (Captions — Pre-recorded), which requires captions that accurately convey the audio content, including speaker identification where necessary. For CDL training video and transit operator training video hosted on state DOT or transit agency websites, the WCAG 2.1 AA accuracy standard applies as of April 2026.

Section 504 of the Rehabilitation Act — federal transportation contractors

Section 504 of the Rehabilitation Act of 1973 prohibits discrimination on the basis of disability by any programme or activity receiving federal financial assistance. In the transportation sector, this applies broadly:

• Motor carriers receiving federal assistance: carriers that operate under federal transportation programmes — government contracts for freight movement, contracts with federal agencies, recipients of USDOT grants — must comply with Section 504. The DOT's Section 504 regulations at 49 CFR Part 27 require recipients of DOT financial assistance to operate accessible programmes. Training programmes produced for or required by federally assisted transportation operations must be accessible.
• CDL schools receiving federal financial assistance: CDL training schools that receive Pell Grants, Workforce Innovation and Opportunity Act (WIOA) funding, or other federal programme funds (which is the majority of community college CDL programmes) are Section 504-covered entities. Their ELDT online training modules, distributed to CDL students receiving federal financial assistance, must be accessible under Section 504.
• FTA Section 504 for transit operators: the Federal Transit Administration's Section 504 regulations require FTA grant recipients (virtually every public transit agency in the US) to ensure that all programmes and activities receiving FTA assistance are accessible. This extends to employee training programmes funded with FTA grant funds. Transit agency new-operator training video — including training on ADA paratransit service requirements and passenger assistance procedures — is typically developed or procured with FTA funds and is therefore subject to FTA Section 504 accessibility requirements.

See the Section 504 captions reference for the detailed framework of Section 504 programme accessibility obligations and the Section 508 captions reference for the electronic and information technology accessibility standards that apply when training is delivered through federally procured technology systems.

State accessibility laws for transportation employers

State anti-discrimination and accessibility laws extend captioning obligations below the federal ADA threshold of 15 employees and add requirements for state-specific contexts:

• California (FEHA — Fair Employment and Housing Act): applies to employers with 5 or more employees; California transportation employers — which include some of the largest domestic trucking companies (XPO, Old Dominion, Werner Enterprises all have major California operations) — have captioning obligations for hearing-impaired employees under FEHA at the 5-employee threshold. The California DMV produces CDL skills test preparation materials that are subject to WCAG 2.1 AA under California Government Code Section 11546.7.
• New York (Human Rights Law): applies to employers with 4 or more employees. New York City's Human Rights Law applies to employers with 4 or more employees and extends to all employees working in New York City. New York's transportation sector — the MTA, Port Authority, major trucking and logistics carriers — is subject to the state Human Rights Law accommodation obligation.
• Texas (Texas Commission on Human Rights Act): applies to employers with 15 or more employees (same threshold as federal ADA) but has been interpreted to cover additional disability accommodation scenarios specific to the Texas transportation sector. Texas-based carriers and CDL schools should note that the Texas Workforce Commission Civil Rights Division enforces accommodation obligations.

ELDT eLearning delivery and caption workflow

FMCSA Training Provider Registry and online ELDT

The FMCSA ELDT rule permits training providers to deliver the classroom (theory knowledge) component of ELDT online as eLearning. The TPR registration process requires training providers to self-certify that their programme meets the curriculum requirements at 49 CFR Part 380. The TPR does not specify technical delivery standards for online content — it does not mandate caption formats, WCAG compliance, or specific LMS platform requirements. The accessibility obligation for online ELDT content comes from ADA Title III (private CDL schools are places of public accommodation) and ADA Title II (public community college CDL programmes), not from the FMCSA ELDT rule itself.

Online ELDT modules are typically delivered as SCORM packages hosted on the training provider's LMS. The SCORM package contains the video assets (typically MP4), the caption files (SRT or VTT), the quiz or assessment elements, and the SCORM JavaScript wrapper that communicates completion status to the LMS. For accessibility, the caption file must be embedded within the SCORM package in a format that the SCORM-packaged video player can render. Common ELDT eLearning delivery platforms used by TPR-registered providers include Articulate Storyline (which packages video with captions in a Storyline course), Adobe Captivate, and custom HTML5 video players within SCORM wrappers. See the Articulate Storyline captions reference for the specific caption embedding workflow for SCORM packages built in Storyline.

Caption format requirements for SCORM-packaged ELDT video: SRT (SubRip Text) files are the most universally supported format for SCORM-packaged video across authoring tools. VTT (WebVTT) is the HTML5 standard and is required for content that will also be published to web pages outside the SCORM package. The FMCSA does not specify a caption format standard for ELDT content; the WCAG 2.1 AA SC 1.2.2 standard requires only that captions be "synchronised with the content" and "accurately convey" the audio — the format (SRT vs VTT) is left to implementation choice.

LMS platforms in transportation training

The commercial transportation sector uses a distinct set of LMS platforms compared to general enterprise L&D, reflecting the specific compliance management focus of motor carrier training:

• J.J. Keller Encompass LMS: the dominant compliance training management platform in the transportation sector, used by over 600,000 businesses including motor carriers, shippers, and CDL schools. Encompass serves primarily as a compliance training catalogue and completion-tracking system. Caption file management for uploaded video content follows Encompass's document management architecture; J.J. Keller's proprietary training content library is captioned but caption quality varies by content age and original production method.
• Samsara Training (in-platform): Samsara's fleet management platform includes an integrated driver training module that delivers short-form safety training videos directly to drivers on their in-cab Samsara tablets. Training delivery is in-platform, not through an external LMS. Caption file support in Samsara's training module is limited; auto-generation of captions for custom training video uploaded to Samsara is not natively supported as of mid-2026.
• Motive (KeepTruckin) Driver Training: similar to Samsara, Motive's fleet management platform includes a driver training module for in-cab video delivery. Caption support follows the same constraints as Samsara's training module.
• TalentLMS: used by mid-size motor carriers and CDL schools for custom training programme delivery. TalentLMS captions support SRT format with specific timing format requirements (comma as decimal separator in SRT files) and direct upload through the course video settings panel. Mid-size carriers building custom ELDT classroom modules or driver orientation courses on TalentLMS need SRT files for each video element.
• Absorb LMS: used by larger transportation companies and logistics operators for enterprise training management. Absorb LMS captions support SRT and VTT upload with a 7-second maximum cue duration and CRLF line endings; silent failures occur with BOM-prefixed SRT files, a known edge case in transportation training workflows where SRT files are generated by multiple vendors.
• Docebo: used by some enterprise motor carriers and logistics companies for blended learning. Docebo captions require VTT format with BCP-47 language tags and the two-step subtitle track API (create track, then upload file) — a more complex workflow than TalentLMS or Absorb LMS that requires programmatic implementation for bulk caption uploads across a large training catalogue.
• Articulate Storyline: the dominant authoring tool for ELDT eLearning content. Articulate Storyline captions are embedded within the course using Storyline's built-in closed caption feature, which requires SRT files and generates VTT output within the published course. For SCORM-packaged ELDT content, the caption file must be correctly imported into Storyline before publishing — a workflow step that training developers frequently miss, resulting in published SCORM packages with no caption track despite the source SRT file existing.

Video types and caption embedding in transportation training

Transportation training video exists in several distinct formats, each with different captioning workflow requirements:

• ELDT eLearning modules: SCORM packages containing video segments on FMCSR knowledge areas. Caption files must be embedded within the SCORM package for each video segment. The common failure mode is SCORM packages published without caption files — either because the authoring tool's caption import step was skipped or because the auto-generated caption file was generated outside the authoring workflow and not imported before publishing. For TPR-registered online training providers, a SCORM package with no caption track is effectively inaccessible to deaf and hard-of-hearing CDL applicants.
• Pre-trip inspection walkthrough video: video walkthroughs of the CDL pre-trip inspection procedure, typically recorded as a camera follows a driver around a tractor-trailer performing the inspection and narrating each step. This video type has high proper-noun and technical vocabulary density — specific component names (steering gear box, slack adjuster, kingpin, fifth wheel, glad hands, landing gear, brake chambers, mud flaps, reflective triangles), procedural vocabulary (air pressure buildup rate in the air brake system, oil pressure gauge interpretation), and references to FMCSA equipment inspection standards (49 CFR Part 393, 49 CFR Part 396). Generic STT fails on all of these specific components names — "slack adjuster" → "slack adjuster" (sometimes handled correctly), "glad hands" → "glad hands" (unusual compound but generally manageable), "kingpin" → "kingpin" (often rendered correctly as a common compound), "fifth wheel" → "fifth wheel" (correct), but "push rod stroke" → "push rod stroke" (correct), "S-cam foundation brakes" → "S cam foundation brakes" or "ess cam foundation brakes" (the S-cam brakes component name fails on the single-letter prefix). Brake adjustment vocabulary — in-stroke limit, automatic slack adjuster, manual slack adjuster — is particularly failure-prone.
• HOS and ELD training screen recordings: screen recordings of an ELD device interface showing drivers how to navigate the ELD menu, log their duty status changes, annotate personal conveyance, and respond to malfunction events. These recordings narrate the specific ELD vendor's interface vocabulary — which is product-specific and changes with software updates — alongside the FMCSA regulatory vocabulary for the requirements the ELD is implementing. This dual-vocabulary failure mode (vendor interface + FMCSA regulatory) is the most challenging captioning scenario in transportation training: every menu item name in the ELD interface is out-of-distribution for generic STT, and the regulatory vocabulary narrated in the context of those interface elements compounds the failure rate.
• HazMat training slide-and-audio modules: narrated slide presentations covering the HazMat classification, labelling, marking, and placarding requirements. The narration layer — describing what each placard looks like, what each UN number means, which packing groups apply to which materials — carries the full HazMat vocabulary failure profile. These modules are often produced by J.J. Keller or similar third-party providers and distributed as SCORM packages to motor carrier LMSs.
• Reasonable suspicion supervisor training video: documentary-style training video covering the symptoms of drug and alcohol impairment and the reasonable suspicion determination process. These videos often include dramatised scenario vignettes — a supervisor observing a driver who exhibits slurred speech or unsteady gait — overlaid with narrated instruction about the 49 CFR Part 382.603 supervisor training requirement and the documentation procedures. The vocabulary includes the full DOT drug and alcohol testing abbreviation set (MRO, SAP, RTD, ODAPC, DER) alongside more common behavioural vocabulary (signs and symptoms of impairment). The regulatory abbreviations fail as described above; the behavioural vocabulary ("slurred speech," "bloodshot eyes," "erratic behaviour") is generally handled well by generic STT.

The GlossCap approach for transportation training video

Transportation training vocabulary has a large shared federal regulatory base layer — common across all motor carriers, CDL schools, and HazMat trainers — combined with a fleet-specific or school-specific overlay covering the particular ELD vendor, equipment models, and employer-specific programme vocabulary.

The shared federal regulatory base layer covers: all CDL class and endorsement letter codes (A, B, C, H, N, P, S, T, X) with consistent capitalisation as regulatory designations; GVWR, GCWR, CMV, CLP, ELDT, TPR, BTW with consistent acronym rendering; all HOS vocabulary (HOS, ELD, DVIR, RODS, AOBRD, Personal Conveyance, Yard Moves, 34-hour restart, sleeper berth with correct "berth" spelling, short-haul exemption, adverse driving exception); ELD malfunction codes (P, E, T, L, R, S, O) as FMCSA-defined single-letter designations; FMCSA safety programme vocabulary (SMS as Safety Measurement System, CSA, BASIC, DataQ, ISS, USDOT Number, MC Number, IFTA, IRP, PrePass, Drivewyze); all HazMat class designations and division numbers; UN numbers in the "UN" + four-digit format; packing groups I, II, III; ERG, TIH, PIH, CHEMTREC, NMFC, SDS as regulatory designations; and drug and alcohol testing vocabulary (MRO, SAP, RTD, ODAPC, DFWP, DER, Part 40, Part 382, blind specimen).

The fleet-specific overlay covers: the specific ELD vendor and product names deployed at the carrier (Samsara, Motive, Omnitracs, PeopleNet, Geotab, Verizon Connect, Trimble, Platform Science — with the carrier's specific product tier and interface name); the carrier's internal safety programme names and metrics (carrier-specific safety score names, internal incident classification vocabulary, internal compliance calendar terminology); specific truck models and configurations in the fleet (tractor model designations, trailer types — reefer, flatbed, container, tanker — specific to the carrier's operations); geographic route and terminal names referenced in orientation training; and any customer or shipper names narrated in HazMat or load-specific training content.

The result: a GlossCap-processed ELDT online module caption track renders "ELDT" as "ELDT" (not "felt"), "PIH" as "PIH" (not "pie"), "Samsara" as "Samsara" (not "Samsung"), "DataQ" as "DataQ" (not "data queue"), "sleeper berth" as "sleeper berth" (not "sleeper birth"), and "DVIR" as "DVIR" (not "driver") — consistently, across every occurrence in the video, without post-production manual correction of each instance. For a CDL school processing 50 ELDT module videos to launch a new online programme, or a mid-size carrier captioning its complete driver orientation library, the vocabulary accuracy improvement compounds across thousands of caption segments.

See GlossCap pricing

49 CFR regulatory citation format in transportation training video

Transportation training video narrates 49 CFR regulatory citations at high frequency — HOS training references 49 CFR Part 395 repeatedly; ELDT training references 49 CFR Part 380 and its appendices; HazMat training references 49 CFR Parts 172, 173, 177, 178; drug and alcohol training references 49 CFR Parts 40 and 382. Each citation is narrated consistently by the trainer in a standard form — "forty-nine C-F-R Part three-ninety-five," "forty-nine CFR section one-seventy-two point seven-oh-four" — but generic STT produces citation format variants that are inconsistent across occurrences in the same video and sometimes incorrect in ways that make the citation non-retrievable in the CFR.

The documented STT variant forms for 49 CFR citations in transportation training video:

• "49 CFR Part 395" (correct — the standard modern format)
• "49 C.F.R. Part 395" (CFR with periods — an older formatting convention still accepted)
• "49 CFR § 395" (with section symbol — used when the citation is to a specific section, not a full part)
• "49 CFR part three ninety-five" (all words — STT renders the part number as words when narrated at lower speed)
• "forty-nine CFR Part 395" (numeral inconsistency — title number as words, part number as numeral)
• "49 C F R Part 395" (CFR letter-spaced — STT renders the acronym as three separate letters)
• "49 CFR 395" (without "Part" — sometimes the STT omits the "Part" keyword when the narrator does not strongly emphasise it)

For a 49 CFR section citation with a decimal — "49 CFR § 172.704" for the HazMat employee training requirement — the additional failure modes are:

• "49 CFR 172.704" (correct)
• "49 CFR 172-704" (hyphen instead of decimal — the most common STT artefact for decimal-separated section citations)
• "49 CFR section 172 point 704" (expanded word form)
• "49 CFR 172, 704" (comma instead of decimal)

For Part 380 appendix citations — "49 CFR Part 380 Appendix A" for the Class A ELDT curriculum — the failure modes include "49 CFR Part 380 Appendix A" (correct), "49 CFR Part 380, Appendix A" (with comma), "49 CFR 380 Appendix A" (without "Part"), and "49 CFR Part 380 appendix a" (lowercase "appendix" and letter). GlossCap applies consistent 49 CFR citation formatting — "49 CFR Part XXX" for part-level citations and "49 CFR § XXX.YYY" for section-level citations — across all occurrences of any 49 CFR citation in transportation training video, eliminating the citation format variance that makes training caption tracks unreliable as regulatory reference documents.

FAQ — DOT/FMCSA transportation training captions

Further reading

• Safety training video captions: OSHA, MSHA, and HazCom vocabulary
• Compliance training video captions: SOX, HIPAA, GDPR acronym vocabulary
• Construction safety training captions: OSHA 1926, fall protection, and crane vocabulary
• Manufacturing training captions: lean/Six Sigma, OSHA 1910, and HACCP vocabulary
• Section 508 captions: federal contractor and government supply chain training
• Section 504 captions: federal financial assistance recipients and transportation agencies
• ADA Title II captions: state DOTs, transit agencies, and the WCAG 2.1 AA hard deadline
• WCAG 2.1 AA captions: what SC 1.2.2 "accurately convey the audio" requires
• TalentLMS captions: SRT upload workflow for fleet and transportation training
• Articulate Storyline captions: SCORM package caption embedding for ELDT modules
• HazCom training captions: chemical names, IUPAC vocabulary, and OSHA 1910.1200