The rule behind this citation is short, and most drivers who get written up under it never read it. Section 393.60(d) says windshield tinting may not permit less than 70 percent light transmittance. That is the whole test. The inspector is not asking whether the glass looks dark, whether it is pretty, or whether the sun is bothering you. They are asking how much light gets through.
Our data records the violation as "Windshield / Windows - Tinting permits less than 70% of light transmittance," under the Vehicle Maintenance BASIC, in the Windshield/Glass/Markings group. You can see the full record on the violation page for 854.
What the rule actually measures
Light transmittance is the share of visible light that passes through a piece of glazing. A reading of 70 percent means 70 percent of the light gets through. Anything below that, measured where the rule applies, is a violation.
The source of the darkening does not change the test. Factory tint, aftermarket film, a bumper-sticker-sized decal in the wrong place, and a sun strip that has crept down the glass can all be measured the same way. If the light that gets through falls below the threshold in the area the rule covers, you have the citation.
One caveat: read the full text of 393.60 before you assume any particular strip or area is exempt or covered. The exact area and exceptions matter, and I would rather you check the regulation than rely on my summary.
Where it sits in the scoring
Here is what our data says about this code:
- Severity weight: 1.
- Out-of-service indicator: No. In our data, this violation does not carry an out-of-service flag, and the out-of-service count recorded for it is 8.
- Scale of occurrence: 157,246 recorded violations across 154,928 inspections where it appeared.
- Used in SMS: Yes.
A severity weight of 1 means this is a low-weight item on paper. Do not take that as permission to ignore it. A tint citation still shows up on your record, it still counts toward the Vehicle Maintenance BASIC, and it still affects how an inspector and a carrier's safety team see your equipment.
The time element matters more than most drivers expect. The calculator weights recent violations more heavily: 3 for the first six months, 2 for months six through twelve, 1 for months twelve through twenty-four, and 0 after that. A citation from last week counts for far more than one from two years ago. You can see how that plays out for a specific set of inputs in the calculator. Run your own numbers there instead of trusting my arithmetic.
The calculator also caps the severity contribution from any single inspection within one BASIC at 30 points, so one inspection with many windshield items cannot push that BASIC's score without limit.
Why it gets missed
Tint problems are rarely the driver's doing on day one. They come from three places:
- Inherited trucks. A unit bought used or moved between drivers may carry film the current driver never saw applied.
- Film that aged. Aftermarket film that has bubbled, faded, or been scraped can change the reading over time, and it may not look different from the driver's seat until it is too late.
- Replacement glass. A windshield swap can bring in glazing with a different transmittance than what came out.
The common thread is that nobody checks the glass on purpose. The pre-trip walks around the truck and looks at lamps, tires, and mirrors. The windshield gets a glance for cracks.
What to do about it
- Add the windshield to your pre-trip. Look for film, stickers, labels, or anything sitting in the view area that was not there before.
- Ask about film on any unit you inherit. If the truck has aftermarket film, find out who applied it and whether there is paperwork showing its rating.
- Keep the paperwork. If you have film installed, keep the product documentation with the unit.
- Fix it at the source. If the glass is below the threshold, the fix is to remove or replace the film or the glass, not to explain it to the inspector.
- Know your state. This citation is based on the federal rule. States may have their own requirements for glazing and tint. Check what applies on the routes you run.
Key takeaways
- Section 393.60(d) requires windshield tinting to permit at least 70 percent light transmittance.
- The test is about light passing through the glass, regardless of where the tint came from.
- Severity weight is 1 and the code does not carry an out-of-service indicator in our data, but it still counts toward Vehicle Maintenance.
- Recent citations weigh more than old ones, so a fresh tint problem is worth fixing quickly.
- The cheapest fix is a windshield check during the pre-trip, before the inspector does it for you.
If you want to know how this and other glass citations age on your own record, the calculator is the place to start, and the glossary covers the transmittance and BASIC terms you will see in the reports.