What 397.7A means in plain language
FMCSR 397.7A prohibits parking a commercial motor vehicle carrying hazardous materials in an unauthorized location. In other words: if your truck is transporting hazmat, you cannot simply pull into any parking area. The regulation requires you to use only approved, designated hazmat parking facilities.
What constitutes "unauthorized" depends on the type of hazmat you're carrying, your destination, and local/state regulations. The rule exists because hazmat vehicles pose heightened risk if parked near populated areas, schools, hospitals, or other sensitive locations. Unauthorized parking could mean parking at a standard truck stop when hazmat regulations require a Class 1 hazmat facility, or parking on a city street when the load should only stop at federally approved hazmat rest areas.
What our enforcement data actually shows
Across our database of 13 million+ roadside inspections, 397.7A has been cited only 1 time in our all-time records, and 1 time in the last 12 months. In the last 90 days, we have recorded 0 citations. This code ranks #2796 of 3,036 FMCSR codes by citation volume—making it exceptionally rare.
When 397.7A citations do occur, they almost never result in out-of-service (OOS) placement. Our data shows a 0.0% OOS rate for this code. This contrasts sharply with the all-FMCSR average OOS rate of 31.4%, indicating that inspectors treat this violation as a warning-level or lower-severity infraction rather than an immediate safety threat warranting vehicle removal from service.
Who gets cited most
Our inspection records show that Texas accounts for 1 citation of 397.7A over the last 180 days, with a 0.0% OOS rate. Because the overall citation volume for this code is so low (1 citation in the entire last 12 months), geographic variation is minimal and not predictive of enforcement risk.
EBT LOGISTICS INC (USDOT 2902337) appears in our data with 1 citation for 397.7A. This isolated citation does not indicate a systemic hazmat parking problem at the fleet level.
How severe is this compared to similar codes
397.7A sits at the low end of hazmat enforcement severity. Here's how it stacks up against related codes in the hazardous materials category:
General hazmat loading/unloading violations are far more frequently cited and carry much higher OOS rates. Code 177.834A-HMC shows 3,954 citations with a 99.2% OOS rate, and 177.834(a) shows 3,839 citations with 97.9% OOS. Both dwarf 397.7A in enforcement volume and consequence.
Placarding violations (177.817(a)) see 2,274 citations with a 75.1% OOS rate—again, far more common and more likely to result in vehicle removal. Even deteriorated placard violations (177.817(e)) show 2,038 citations despite a lower 5.2% OOS rate.
Damaged hazmat movement (177.823(a)) generates 1,829 citations at 51.8% OOS. By contrast, our inspection records show 397.7A citations are so infrequent that they represent a negligible portion of hazmat enforcement activity.
How to avoid it
Because 397.7A violations are so rarely cited, the best approach is understanding hazmat parking rules before you depart:
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Know your hazmat destination before loading. Identify approved hazmat parking facilities along your route. Use the USDOT's hazmat placard requirements and state-specific hazmat rest area maps. If you don't know where you're legally permitted to park your load, don't accept the load.
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Never park at a standard truck stop with hazmat on board. Even if the facility allows oversized vehicles or has fuel, standard truck stops are unauthorized for hazmat parking unless explicitly designated. Check with dispatch or your carrier's hazmat coordinator before every stop.
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If you must rest during a hazmat haul, pull only into federally designated hazmat rest areas or hazmat-approved truck stops. These facilities meet DOT safety standards for hazmat vehicle storage. Your company should provide a pre-trip briefing listing approved facilities on your route.
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Verify your truck's hazmat documentation and placards are complete and readable. While placarding violations are cited far more often than 397.7A, correct placarding is the baseline that alerts weigh stations and inspectors that your vehicle is hazmat-restricted in the first place.
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Communicate with your dispatcher about rest breaks. If you're tired on a hazmat load and need to sleep, tell your dispatcher. They should route you to an approved facility or arrange for a second driver. Never improvise a parking spot.