FMCSR 393.78(a) – Defective Windshield: Driver FAQ

No. Across all 13,852 citations for 393.78(a) in our inspection records, zero vehicles were placed out of service — a 0.0% OOS rate. This code is not OOS-eligible under the North American Standard Out-of-Service Criteria. For context, the all-FMCSR average OOS rate is 31.4%, so this violation sits well below the typical threshold. You keep rolling, but the citation still hits your CSA record, so don't treat it as consequence-free.

393.78(a) carries a severity weight of 4 in the CSA SMS. That base score is then multiplied based on how recently the inspection occurred: violations in the last 6 months receive the highest time-weight multiplier, violations from 6–12 months ago receive a lower one, and violations older than 12 months apply no time multiplier. Because 393.78(a) is assigned to the Vehicle Maintenance BASIC, the points follow the inspection record for 36 months. A single citation is moderate, but repeated citations stack quickly and push your Vehicle Maintenance BASIC percentile higher.

Act on the windshield immediately, even though you aren't placed out of service. Concrete next steps:

1. Document the current condition — photograph the damage before any repair.
2. Schedule repair promptly — get a shop receipt showing the date of correction.
3. Check your peer code exposure — our records show 393.78 (the parent code) has 157,894 citations; inspectors who flag windshield condition often look at overall maintenance posture, so review lighting, lamps, and inspection documentation on the same unit.
4. File the repair record with your fleet safety manager or keep it in the vehicle file.
5. Verify the citation details are accurate before the 60-day DataQs window closes.

It's moderate in frequency and low in OOS risk relative to peers. 393.78(a) ranks #180 out of 3,036 FMCSR codes by citation volume, so inspectors do write it regularly. The 0.0% OOS rate contrasts sharply with peer codes in the same Vehicle Maintenance category: 396.3(a)(1) carries a 45.3% OOS rate across 236,919 citations, and even 393.9(a) for inoperable required lamps hits 15.4% across 660,737 citations. So while 393.78(a) won't park your truck, it signals to inspectors that the vehicle's maintenance culture may need attention.

Yes, you can challenge it. The FMCSA DataQs system (Request for Data Review, or RDR) is the formal channel for contesting inspection findings on your record. Because 393.78(a) is an equipment-condition finding — not a documentation issue — a successful challenge typically requires evidence that the windshield did not impair the driver's view at the time of inspection: photographs taken at or near the inspection, a pre-trip inspection log, or a repair record showing the windshield was already in serviceable condition. Submit the RDR within 60 days of the inspection date for the strongest case. The inspecting agency reviews the evidence and can remove or amend the violation if your documentation supports it.

The top carriers cited for 393.78(a) in our database point to heavy enforcement concentration along U.S.-Mexico border corridors. The three carriers with the highest all-time citation counts are OCTAVIO ANDRADE CORELLA (34 citations), BELTRAN BROTHERS LLC (28 citations), and RICARDO ANDRES PENA COTA (28 citations) — all operating in border-region markets. FEDERAL EXPRESS CORPORATION (21 citations) and WASTE MANAGEMENT INC OF FLORIDA (20 citations) round out the list, indicating the violation also surfaces in high-cycle urban and regional fleets. If your operation runs border crossings or high-frequency urban routes, windshield condition is an active inspection focus.

Fix it before the next inspection, but the data shows no immediate shutdown risk. The 0.0% OOS rate across 13,852 all-time citations confirms inspectors are not parking trucks over this code. However, the last 12 months and last 90 days each show 0 new citations in our records — meaning enforcement volume has dropped to zero recently. That trend could reflect seasonal patterns or reclassification, not a relaxed standard. Practically speaking: a documented repair protects you from a repeat citation, strengthens any DataQs challenge, and removes a visible defect that can escalate an inspector's scrutiny of the rest of your vehicle.

It follows both. In FMCSA's CSA system, a Vehicle Maintenance BASIC violation like 393.78(a) is attributed to the carrier whose USDOT number appears on the inspection report. However, if you were the driver of record, the inspection also links to your CDL and appears in your personal inspection history. Carriers use driver inspection histories during hiring reviews. The severity weight of 4 sits on the carrier's Vehicle Maintenance BASIC for 36 months and on your driver record for the same period, so both parties have an incentive to get the repair documented and, if warranted, the finding challenged through DataQs.