What 172.502A1 means in plain language
When you haul hazardous materials, your truck must display placards—specific labeled signs on all four sides (front, back, both sides). These placards identify what hazardous cargo you're carrying so emergency responders know what they're dealing with if something goes wrong.
172.502A1 is about general placarding compliance. An inspector will cite you for this violation if your truck is transporting hazmat and the required placards are missing, illegible, improperly positioned, or otherwise fail to meet the basic placarding rules. This is different from placards that are just deteriorated or damaged—those fall under different codes. This citation means the placards themselves weren't there or weren't correct to begin with.
If you were cited, it means an inspector at a roadside stop found your truck carrying hazmat without proper placards displayed.
What our enforcement data actually shows
Across 13 million inspections in our database, we've recorded 864 all-time citations for 172.502A1. In the last 12 months, that's 434 citations, and in the last 90 days, 90 citations. This code ranks #752 out of 3,036 FMCSR codes by citation volume—not the most common violation, but steady.
The out-of-service rate for 172.502A1 is 27.8%. That means roughly 240 trucks were placed out of service for this violation versus 624 that were cited but allowed to continue. This OOS rate sits slightly below the all-FMCSR average of 31.4%, indicating that while inspectors do remove trucks from service for placarding failures, it's not automatic—context and severity matter.
Monthly trend data shows enforcement is active year-round. Looking at the last 12 months, we see citations ranging from 11 in April 2025 to 55 in May 2025, then settling into the 30–47 range most months, with December 2025 and February–March 2026 showing elevated out-of-service placements.
Who gets cited most
Our inspection records show Texas dominates 172.502A1 enforcement by far. In the last 180 days, Texas accounted for 200 citations—far ahead of any other state—with 53 of those resulting in out-of-service orders (26.5% OOS rate). Illinois follows distantly with 12 citations but a 0% OOS rate. Iowa, North Carolina, and New Mexico round out the top five, each with 3–4 citations and no out-of-service placements.
The gap between Texas and other states reflects both the volume of hazmat transport in Texas and heightened inspection activity on major routes. If you operate in Texas, expect closer scrutiny of your placards.
Our data shows fleets such as Quality Tank SA de CV and Trophy Trucking Services LLC with 11 citations each across all years. Other carriers in the top list include Trareysa SA de CV with 8 citations. These numbers alone don't indicate a pattern of negligence—they reflect the size and regional focus of those operations. Placarding is a basic requirement that any carrier hauling hazmat must manage correctly.
How severe is this compared to similar codes
Placarding violations span a range of codes in the hazardous materials category. Our data shows significant variation in OOS rates across similar violations:
- 177.817(a) (Placarding violation) has seen 2,274 citations with a 75.1% OOS rate—nearly three times higher than 172.502A1. That code captures more severe placarding failures.
- 172.502(a)(1) (Placarding general requirements, slightly different subsection) has 1,820 citations and an 18.5% OOS rate—lower than 172.502A1's 27.8%, suggesting A1 is cited for more concrete violations.
- 172.516(c)(6) (Placard damaged, deteriorated, or obscured) shows 1,796 citations but only a 1.6% OOS rate, indicating inspectors treat damaged placards as minor compared to missing or incorrect ones.
Your citation falls in the middle of the severity spectrum. You weren't cited for loading or unloading hazmat incorrectly (those codes reach 95%+ OOS rates), but your placarding failure was serious enough to warrant enforcement.
How to avoid it
Preventing a 172.502A1 citation requires discipline in your pre-trip inspection and load verification:
Before you load:
- Verify the shipper has provided correct placard information for every material on your truck. Don't assume—get it in writing.
- Know which placard class and ID number apply to each commodity. If you're uncertain, ask the shipper or your dispatcher before accepting the load.
- Check your placards themselves for legibility and condition before they go on the truck.
During your pre-trip:
- Walk all four sides of the truck and confirm placards are present, correct, and properly positioned (typically 3 inches from the edge and securely fastened).
- Verify that the placard ID number and class label match your bill of lading.
- If a placard is missing or illegible, stop—don't move the truck until it's corrected.
Common hazards to watch for:
- Our inspection data shows that trucks cited for 172.502A1 often have overlapping equipment or maintenance issues. In the last 90 days, placarding violations co-occurred with inoperable lamps (21 shared inspections), missing fire extinguishers (14 shared inspections), and windshield defects (13 shared inspections). Keep your truck in good mechanical condition—inspectors conducting a roadside stop are more likely to dig deeper if your vehicle shows other defects.
- Inoperable turn signals and brake issues also appeared frequently alongside placarding citations. A truck that looks poorly maintained invites scrutiny of everything, including placards.
Vehicle-specific note:
- Freightliner trucks account for 264 of all 172.502A1 citations in our database, followed by Kenworth with 152. If you drive one of these common models, placarding failures may be slightly easier for inspectors to spot simply because they inspect these vehicles more often by volume. No model is more or less compliant—higher citation count reflects exposure.
The simplest rule: confirm your load, confirm your placards match the load, confirm all placards are on the truck before you leave the dock. A few minutes of verification beats a citation and downtime.