← Risk register SOC 49-3031 · reviewed 2026-08-11

Bus and Truck Mechanics and Diesel Engine Specialists

289,960 US workers · median $61,770/yr · Trades

SAFE

The core of this job — pulling injectors, replacing turbos and clutches, chasing air-brake leaks, rebuilding after-treatment systems, and torquing head bolts on a Class 8 engine in a cramped bay or on a roadside — is physical work in awkward, dirty, non-standardized spaces that current robotics cannot touch. AI is already eating the diagnostic-lookup layer: fault-code interpretation, service-manual search, repair-order write-ups, and parts ordering are moving to software fast. What survives is the hands, the ear for a misfire, and the accountability for signing a DOT annual inspection or a brake job that has to hold at 80,000 lbs.

10-year outlook: Demand holds through 2035 as freight and transit fleets age and electrify; AI takes over the diagnostics and paperwork, which shifts the job toward more wrench time per shift and a growing premium on EV/HV-qualified techs.

US employment, 2019–2025+8.9%
266,330289,960 workers

Dipped in 2020, then grew past where it started.

Median pay $48,500 → $61,770 +1.9% in real terms (nominal +27.4%, less ~25% US inflation over the period)

The job count is not the verdict

This line is counted by the Bureau of Labor Statistics — the one figure on this page that isn't a judgement of ours. Headcount moves on demand, offshoring, demographics and the business cycle, and automation is one term among several, often not the loudest.

So a falling line is not evidence that AI did it, and a rising one is not evidence that it won't. Both happen in this register: some occupations resist automation and shrink anyway, others are highly automatable and keep growing. The marked year is 2020.

BLS projection, 2024–2034

+2.4% 319,900 → 327,700 on the projections basis

Hard to automate, and growing

The work resists current AI and the BLS projects +2.4% more of these jobs by 2034. Note that safe does not mean well paid — several of the fastest-growing resistant occupations are among the lowest paid on the register.

Different clocks. The score is what current AI could do to this work today. The projection is how many of these jobs will exist in 2034. Everything between the two — how fast employers actually adopt, whether demand grows in the meantime — is why they can point opposite ways without either being wrong.

~26,500 openings a year on average, including replacing people who leave.

One email if this score changes. Watch as many occupations as you like from the same address — no account, and nothing is sent on a schedule, only when a verdict actually moves.

Also known as — 24 job titles this covers

Titles reported by people doing this work, from the US Department of Labor's O*NET survey. If your job title is here, this page is about your work even though the name doesn't match.

Bus MechanicBoat MechanicBus OverhaulerFleet MechanicMotor MechanicTractor ExpertTruck MechanicDiesel MechanicEngine MechanicService AdvisorDiesel MachinistTractor MechanicTrailer MechanicTransit MechanicTruck OverhaulerBus Motor MechanicService TechnicianBus Engine MechanicBus Garage MechanicHeavy Duty MechanicLocomotive MechanicSchool Bus MechanicBoat Engine MechanicBus Tune-Up Mechanic

Score — 68/100 resistance

Holding it up: embodiment (19/20). Weakest point: liability shield (9/20).

Five dimensions, 0–20 each, summed. Higher means more protected. The arithmetic is shown so you can check it: 16 + 19 + 9 + 11 + 13 = 68. · Scored 2026-08-11, and re-examined when evidence accumulates rather than on a schedule.

Task resistance 16/20

Tasks largely resist digitisation Diagnostics-by-code is genuinely being automated, but nothing in software drops a transmission, presses a wheel seal, replaces a DPF, or reseats a leaking air line on a trailer parked in gravel — that's why this sits at 16 rather than a clean 19.

Embodiment 19/20

Hands-on in uncontrolled environments You work under a chassis on your back, on a creeper in a bay with no climate control, on roadside calls in weather, and inside engine compartments where reaching the No. 6 injector means removing the valve cover by feel — the only reason it isn't 20 is that some of the shift is at a laptop running OEM software like Cummins INSITE or DDDL.

Liability shield 9/20

Certification preferred, not legally required No state licence is required to turn wrenches on a Class 8 truck, but FMCSA 396.19 requires you to be a qualified brake inspector to sign off brakes and 396.17 inspections, and ASE T-series plus 609 refrigerant certification is what shops hire on — a real credential gate, just one the shop owner and motor carrier ultimately carry the DOT liability for.

Trust premium 11/20

Some relationship component Fleet maintenance managers keep the mechanic who knows their specific 40 units, which spec'd engines run hot, and whose word on "that one's not safe to dispatch" gets believed without a second opinion — but the relationship travels with the shop and the work is verifiable by the repair, so it's not the product itself.

Judgment & accountability 13/20

Meaningful discretion Deciding whether a cracked frame rail, a marginal drum thickness, or an intermittent ABS fault means out-of-service or another 10,000 miles is your call with an 80,000 lb vehicle and a CSA score behind it; it stops short of 16+ because OEM service specs, wear limits, and FMCSA appendix criteria give you hard numbers to hang most decisions on.

Confidence: high · reviewed 2026-08-11 · how scoring works · 1 deployment report on file

What this job involves — and which parts are yours

The verdict above describes this occupation as a whole. Almost nobody does the typical version of a job — tick what's actually in your week and see how your own mix sits.

AI already does these at usable quality

These still need a person

Active moats on the surviving side: embodiment, liability, judgment

How to future-proof this job

Where to go deeper on what this job runs on: MIT OpenCourseWare — circuits, systems and diagnostic method, free and ungated free · Apprenticeship.gov — paid, employer-sponsored trade apprenticeships, searchable by trade and ZIP paid to train · edX — operations management and process monitoring courses free to audit · Apprenticeship.gov — industrial maintenance and millwright programs paid to train · Coursera — critical thinking and logic, audit free free to audit · Coursera — quality control and inspection courses, auditable free free to audit

All 35 skills ranked by how many jobs they open →

What would move this back up — beyond any one person

The moves above are yours to make. This is the other half: what would have to change in the world for the occupation itself to score higher. None of it is in any one person's gift, but it is where the floor actually comes from. Scores here are not a one-way ratchet. Only two of the five dimensions — task resistance and embodiment — track what machines can do. The other three track law, what buyers will pay for, and who is answerable, and those move in both directions, often in response to the same pressure AI creates. If every lever below landed, this occupation would score around 83/100, still SAFE.

5 specific changes that would raise this score
  • already happening liability shield +3

    High-voltage certification for battery-electric and hydrogen buses/trucks becoming a legally required, individually held credential (NFPA 70E-style qualified-person rules, OSHA enforcement on live HV work) so that a named certified human must sign off on pack service and isolation.

  • already happening task resistance +2

    Genuine two-tier job: as fault-code interpretation, manual lookup, parts ordering and repair-order write-up move to software, the residual day is intermittent faults, wiring-harness chafe, after-treatment root-cause, and post-collision structural judgment — the tier no diagnostic model closes. No law needed; visible where dealer groups already have AI triage front-ends.

  • plausible liability shield +4

    FMCSA already requires a qualified brake inspector (49 CFR 396.25) and a signed annual inspection report (396.17/396.21). A rule change making the individual technician — not just the motor carrier — personally sanctionable when a signed inspection precedes a brake-related crash, or a state adopting technician licensure for heavy-vehicle brake and steering work (as some states have floated in the wake of CVSA out-of-service data), would push this well up.

  • plausible trust premium +3

    Fleet liability insurers or self-insured carriers writing policy conditions that require documented ASE-certified (T-series) human inspection of brakes and steering at set intervals, refusing coverage for AI/remote-diagnostic-only sign-off — analogous to insurer-mandated crane and boiler inspection clauses.

  • plausible judgment accountability +3

    Task-mix shift plus formalization: if OEM telematics auto-schedules routine service, the remaining human call is the out-of-service / 'is this truck safe to load' decision. A CVSA or carrier policy making that determination a named-technician written judgment (rather than a dispatcher's call) raises ownership of the consequential call.

The limit. Embodiment at 19 is effectively capped — roadside and cramped-bay work is the hard ceiling for robotics and there is no route upward. Trust premium is structurally limited: fleet buyers purchase uptime and cost-per-mile, not human craftsmanship, so gains there must come through insurer or warranty conditions rather than customer preference.

These are conditions, not forecasts — what would have to happen, not what will. Specific rules, cases and bills are named so you can go and check whether they exist and where they stand; verify before relying on any of them. Nothing here is legal or financial advice.

Where this work is, and what it pays there

BLS metro figures for 389 areas. The verdict above does not change by city — the rubric judges what the work involves, not where it happens — but pay and headcount do, and the national median hides a very wide range.

Most of these jobs

New York-Newark-Jersey City, NY-NJ 12,430 $75,780 +23%
Chicago-Naperville-Elgin, IL-IN 8,660 $65,680 +6%
Dallas-Fort Worth-Arlington, TX 7,940 $60,390 -2%
Houston-Pasadena-The Woodlands, TX 7,410 $60,770 -2%
Los Angeles-Long Beach-Anaheim, CA 6,520 $77,380 +25%
Atlanta-Sandy Springs-Roswell, GA 5,940 $62,270 +1%
Philadelphia-Camden-Wilmington, PA-NJ-DE-MD 4,490 $64,550 +5%
Minneapolis-St. Paul-Bloomington, MN-WI 4,290 $73,730 +19%

Best paid

San Jose-Sunnyvale-Santa Clara, CA 720 $88,980 +44%
Urban Honolulu, HI 540 $85,040 +38%
Seattle-Tacoma-Bellevue, WA 3,740 $82,330 +33%

Percentages are against this occupation's national median of $61,770. Counts are jobs in that metro, not vacancies. Metros where the BLS suppressed the cell are absent rather than shown as zero.

Who is actually doing this

The score above is about what the work exposes. This is reporting about real deployments in this occupation — the difference between "could be automated" and "somebody automated it."

Ryder

1 of 1 reported case, with sources

Quick take — do you do this job?

Has AI actually changed your work? One tap, anonymous, and the running tally is public. Nothing else is asked of you.

Self-reported and unverified — a sentiment signal, not a survey. One response per person per occupation; you can change your answer.

Field reports — what people say has changed

No field reports yet. A written account takes a paragraph rather than a tap, goes to an editor before it appears, and is the one thing on this page the rubric cannot produce on its own.

File a field report

Concrete beats general: a tool that arrived, a task that moved, a headcount decision you watched happen. Don't include anything that identifies you or your employer if that would put you at risk.

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Kept current

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