What 397.3-SLL means in plain language
This citation means you operated or parked a commercial motor vehicle carrying hazardous materials in a way that broke a local, state, or municipal law or ordinance in the jurisdiction where you were driving. Unlike federal hazmat rules that apply everywhere, each state and county can impose its own restrictions—whether that's prohibiting certain routes, banning hazmat parking in residential zones, restricting hours of operation for hazmat transport, or requiring special permits to enter specific areas.
The key is that you violated something written in the local code, not a federal FMCSR. An inspector discovered that breach during a roadside stop, either by observing where or how your vehicle was positioned, checking your routing documents, or finding that you lacked required local permits or approvals.
This is a hazardous materials category violation, but it's distinct from federal placarding, loading, or emergency response infractions. It targets your compliance with geography-specific rules that apply only in that jurisdiction.
What our enforcement data actually shows
Across our 13 million inspection records, 397.3-SLL is cited infrequently and almost never results in an out-of-service order. All-time, there are 382 citations on record with an out-of-service rate of just 1.0%—four vehicles placed OOS and 378 not. This compares sharply to the all-FMCSR average out-of-service rate of 31.4%, making 397.3-SLL one of the least disruptive violations an inspector can write.
In the last 12 months, our data shows 213 citations for this code nationwide. Over the past 90 days, we've recorded 50 citations. The code ranks #1007 out of 3,036 FMCSR codes by citation volume, meaning it's a relatively low-frequency violation. However, the enforcement trend has fluctuated: January 2026 saw 33 citations (the highest month in the trailing 12-month window), while April 2025 had only 4.
Who gets cited most
California dominates the geographic distribution: across the last 180 days, we recorded 87 citations in CA with a 0.0% out-of-service rate. West Virginia follows distantly with 4 citations (0.0% OOS), and Nevada had 3 citations (0.0% OOS). Colorado and Pennsylvania each had 2 citations with no out-of-service placements.
The concentration in California likely reflects the state's extensive local hazmat ordinances, particularly around Los Angeles, San Francisco Bay, and San Diego port areas, where municipal codes often restrict routes, times, and parking for hazmat vehicles. Other high-citation states may have similar urban or port-adjacent jurisdictions with strict local rules.
Among carriers, our data shows fleets such as Old Dominion Freight Line Inc (USDOT 90849) with 8 citations and KAG West Energy LLC (USDOT 134406) with 7 citations. Central Transport LLC (USDOT 661173) also appears with 7 all-time citations. These figures do not imply negligence—they reflect the scale and operational footprint of larger carriers moving hazmat across multiple regulated jurisdictions.
How severe is this compared to similar codes
Within the hazardous materials category, 397.3-SLL sits at the lower end of severity. For comparison:
- 177.834A-HMC (general loading/unloading of hazmat) has 3,954 citations with a 99.2% out-of-service rate—meaning nearly every violation results in an immediate vehicle removal.
- 177.817(a) (placarding violations) has 2,274 citations with a 75.1% OOS rate.
- 172.502(a)(1) (general placarding requirements) has 1,820 citations with an 18.5% OOS rate.
- 172.516(c)(6) (placard damaged, deteriorated, or obscured) has 1,796 citations with only a 1.6% OOS rate, similar to 397.3-SLL.
The contrast is stark: while loading and placarding violations can shut you down immediately because they create direct safety risks, a 397.3-SLL citation reflects a regulatory paperwork or routing misstep in a specific locality. Inspectors rarely deem it serious enough to remove the vehicle from service on the spot.
How to avoid it
Because this code stems from local laws that vary by jurisdiction, prevention depends on knowing the rules before you enter a new area:
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Research local hazmat ordinances before routing. Before accepting a load destined for a major city or port, check the state and municipal hazmat restrictions for that area. California, Texas, and New York counties often have stricter rules than federal baseline. Contact local permitting authorities or use a route-planning tool that flags hazmat restrictions.
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Carry and present required local permits. Many jurisdictions require a local hazmat transportation permit or a signed confirmation that your route complies with local law. Obtain these before you depart and keep them accessible in your cab.
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Verify parking and fueling restrictions. Some areas prohibit hazmat vehicles from parking in certain zones or require designated hazmat fueling stations. Ask dispatch where it's legal to park and refuel in your destination area.
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Inspect brakes and tires thoroughly during pre-trip. Our inspection data shows that 393.47E (slack adjuster defects) and tire-inflation violations (393.75A3) commonly co-occur with 397.3-SLL citations—suggesting that local inspectors may cite local violations when they also find mechanical defects. A compliant vehicle is less likely to receive secondary citations.
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Pay attention to signage and hazmat placarding condition. Five co-occurring 392.2 (operating while ill/fatigued) citations suggest that tired or inattentive driving may lead inspectors to pull over hazmat vehicles for scrutiny. Stay alert, know your route, and don't shortcut pre-trip walkarounds.
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Keep emergency response information current and accessible. Four inspections show co-occurrence with 172.600C1-HMER (emergency response information missing or unavailable). Ensure your shipping papers and emergency contact details are in the cab and legible.
The core takeaway: 397.3-SLL is avoidable through advance planning and routing compliance. It rarely results in downtime, but it does create a record. Work with your dispatcher to ensure hazmat loads are routed through compliant corridors and that you have local documentation before you roll.