What 393.60(b) means in plain language
FMCSR 393.60(b) addresses windshield and front side window tinting or coatings that reduce the amount of light passing through the glass below legal limits. The rule exists because inspectors and other road users need to see into your cab clearly—reduced visibility through the windshield or front side windows creates a safety hazard.
This isn't about aftermarket window tint for cosmetic reasons alone. The violation captures any material applied to or present on the glass that measurably blocks light transmittance beyond what federal and state vehicle codes permit. Even wear, discoloration, or adhesive residue can trigger this citation if it crosses the light-transmission threshold.
What our enforcement data actually shows
Across our 13 million+ inspection records, 393.60(b) has generated 670 all-time citations, ranking it #828 out of 3,036 FMCSR codes by volume. In the last 12 months and last 90 days, we recorded zero citations for this violation, suggesting it is rare in current enforcement.
When this violation does result in an out-of-service order, it happens only 1.2% of the time (8 OOS placements out of 670 citations). This is substantially lower than the all-FMCSR average OOS rate of 31.4%, indicating that inspectors typically issue a citation for correction rather than immediately removing the vehicle from service.
Who gets cited most
Our data does not include state-level breakdown for this specific code, so we cannot identify the top three states by citation count. However, the top carriers cited for 393.60(b) in our all-time records include CESAR ERNESTO GONZALEZ HERNANDEZ & INOCENCIO GONZALEZ CARDONA (USDOT 1075663) with 3 citations, and several fleets with 2 citations each—including WESTERN EXPRESS INC, JOHN G SAAB, US XPRESS INC, SCHMIDT'S INC, HTS CONSTRUCTION INC, THE STOP & SHOP SUPERMARKET COMPANY, J B HUNT TRANSPORT INC, CAPE COD EXPRESS LLC, and N & B TRUCKING INC.
The most frequently cited vehicle makes in our database for 393.60(b) are Freightliners (48 citations), International trucks (22 citations), and Hinos (18 citations). Kenworths, Peterbilts, Fords, Volvos, Utilities, Macks, and Guangdong trucks also appear in the citation history.
How severe is this compared to similar codes
Within the Vehicle Maintenance category, 393.60(b) is significantly less common than peer violations. For perspective:
- 393.9(a) (Inoperable required lamps) has 660,737 citations with a 15.4% OOS rate—roughly 1,000 times more frequent than 393.60(b).
- 393.78 (Windshield condition defective) has 157,894 citations with a 0.3% OOS rate—also more prevalent, but its OOS rate is even lower.
- 396.17(c) (No proof of periodic inspection) has 198,331 citations with a 0% OOS rate—meaning citations are issued but vehicles are rarely placed out of service.
The pattern shows that 393.60(b) is one of the least-enforced maintenance codes in the database, and when it is cited, the likelihood of immediate removal from service is minimal.
How to avoid it
Take these concrete steps before your next roadside inspection:
- Check your windshield and front side windows in daylight. Look for any film, coating, sticker residue, or severe discoloration that could block light transmission. If you can barely see through it at an angle, it may fail the light-transmittance test.
- Remove aftermarket tint or window film if your vehicle has it. Many states and federal FMCSR rules restrict or prohibit windshield tint on commercial vehicles. Don't assume dark glass from the factory meets the rule—verify with your fleet manager or a glass shop.
- Clean thoroughly. Dirt, adhesive residue from old stickers, or road grime can accumulate and reduce clarity. Use glass cleaner and lint-free cloths on both sides of the windshield and front side windows during your pre-trip inspection.
- Inspect for damage or delamination. Cracked or peeling windshields sometimes trap air bubbles or film that reduces light transmittance. If your windshield is damaged, have it replaced rather than repaired.
- Know your state's rules. While FMCSR 393.60(b) sets the federal baseline, some states have stricter limits or specific testing methods. Coordinate with your fleet safety manager to confirm what passes inspection in the states where you operate.
- Document any recent glass work. If you've had your windshield replaced or repaired, carry proof of the work and the installer's certification that the replacement glass meets legal light-transmittance standards.
Because this citation is rare and carries a very low OOS rate, your immediate risk is a minor violation and a citation on your record. However, compliance is straightforward: keep your windshield and front side windows clean, uncoated, and clear of any aftermarket film that reduces visibility.