397.7 — Improper parking of hazmat vehicle
49 CFR 397 • Hazardous Materials BASIC • Severity 5/10
What this violation means
Hazmat-placarded vehicle parked within 300 feet of a bridge, tunnel, building, or 'place where people work, congregate, or assemble' (with limited exceptions). 5 SMS points. Drivers haul hazmat then stop for fuel and the parking-distance rule trips them up.
Why this gets cited
Truck stops with hazmat areas filled up, driver parks in the general lot. Rest areas. Restaurant parking. Driver not aware of placard load.
How to fix / prevent
Use designated hazmat parking at fuel stops. Plan fuel breaks before reaching populated areas. If carrying hazmat, route around dense urban areas where possible.
Out-of-service criteria
No — this violation is not typically out-of-service eligible. The inspector will note 397.7 on the inspection report (form MCS-63), but the truck/driver can usually continue after the inspection ends. It still counts against the carrier in CSA scoring (severity 5/10 weight, time-weighted over 24 months) and shows on the driver's PSP record. A pattern of these non-OOS violations across multiple inspections is what triggers FMCSA intervention — a single citation rarely does.
CSA / SMS impact
397.7 carries a severity weight of 5/10 in FMCSA's Safety Measurement System (SMS). Higher weights mean faster CSA percentile movement. Combined with a time-weighting factor (2× for citations within the last 6 months, decaying over 24 months), this violation can move your Hazardous Materials BASIC percentile significantly if it stacks with similar citations across your fleet. The threshold for FMCSA intervention is the 65th percentile for most BASICs (50th for Hazmat and Passenger Carrier). Once you cross that, FMCSA can send a Warning Letter, Off-Site Investigation, or full Compliance Review.
How to read this: a single citation rarely puts you over threshold — it's the pattern. Track your inspection rate per power unit and aim for OOS rate under 5% (industry average is 21%).