393.60 — Windshield cracked or discolored in driver's view
49 CFR 393 • Vehicle Maintenance BASIC • Severity 2/10
What this violation means
Crack, chip, or discoloration in the driver's primary viewing area. 2 SMS points. Not OOS unless severely obstructed. Inspectors generally measure — cracks more than ¼ inch wide or chips bigger than ¾ inch trigger citation if in the driver's primary sweep area.
Why this gets cited
Rock strikes from following too close. Frame flex on heavy loads cracking unsupported glass. Hot/cold cycling expanding small chips.
How to fix / prevent
Repair chips quickly with windshield repair kits or shop service ($60-150) — they spread once the chip becomes a crack. Replacement is $300-1,200 for a Class 8 windshield. Many fleets keep a chip-repair vendor on-call for fleet trucks.
Out-of-service criteria
No — this violation is not typically out-of-service eligible. The inspector will note 393.60 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 2/10 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
393.60 carries a severity weight of 2/10 in FMCSA's Safety Measurement System (SMS). Higher weights mean faster CSA percentile movement. Combined with a time-weighting factor (1× for citations within the last 6 months, decaying over 24 months), this violation can move your Vehicle Maintenance 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%).