What 393.62(a) means in plain language
Windshield wipers on your commercial motor vehicle must be in working order. This means both wipers need to function properly when you activate them—they can't be missing, broken, or non-functional. The regulation covers the wipers themselves, not the washer fluid system, though both contribute to visibility.
When an inspector checks your rig, they're looking at whether your wipers actually move across the windshield and clean it. If one or both wipers are inoperative or missing entirely, you're in violation. This is a straightforward mechanical check that happens during a Level 1 or Level 2 inspection.
What our enforcement data actually shows
Across our 13 million+ inspection records, we've recorded 735 all-time citations for inoperative windshield wipers. Over the last 12 months and last 90 days, we've seen zero new citations logged in our system, suggesting this violation has become less common in recent roadside enforcement activity.
However, the consequence rate is notably high: when this violation is cited, 78.0% of those citations result in out-of-service placement—well above the all-FMCSR average of 31.4%. This means that when inspectors find inoperative wipers, they're placing vehicles out of service roughly four out of every five times. Despite ranking #799 out of 3,036 FMCSR codes by total citation volume, the severity of enforcement action is significant.
The gap between the citation count and the OOS rate tells an important story: while this violation isn't among the most frequently cited defects, when it is found, inspectors treat it seriously.
Who gets cited most
Our inspection records don't break down citations by state for this specific code, but we can tell you which carrier fleets have accumulated citations in our database. First Student Inc (USDOT 354406) leads with 19 citations, followed by Durham School Services LP (USDOT 350651) and Sfiniex Line Express Inc (USDOT 591725), each with 11 citations. Other fleets such as Kings Canyon Unified School Dist and Quick Transit Management Agency LLC have also been cited multiple times.
The concentration of citations among school transportation and transit operators suggests that fleet size and intensive daily operation schedules increase exposure to roadside inspection.
How severe is this compared to similar codes
Inoperative windshield wipers falls in the Vehicle Maintenance category alongside several peer violations. To put this in perspective:
Inoperable required lamps (393.9(a)) has been cited 660,737 times with a 15.4% OOS rate—far more frequent but less often resulting in out-of-service placement.
Windshield condition defective (393.78) shows 157,894 citations with only a 0.3% OOS rate. Even though that code covers windshield damage and condition problems, it's enforced at much lower OOS severity than inoperative wipers.
Inspection/repair/maintenance - general (396.3(a)(1)) records 236,919 citations with a 45.3% OOS rate, which is closer to our 78% but still meaningfully lower than the wiper enforcement pattern.
The data indicates that inspectors view non-functional wipers as a critical safety issue warranting immediate out-of-service action far more often than related visibility or maintenance violations.
How to avoid it
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Check both wipers before every shift. During your pre-trip, activate the wipers and confirm they move smoothly across the full windshield without skipping or stalling. If resistance is high or movement is jerky, the blades or arms may be binding and need replacement.
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Replace wiper blades at the first sign of streaking or skipping. Don't wait until they're completely non-functional. Most fleet garages stock replacement blades for common makes like Ford and International (which represent the majority of citations in our data). Worn blades fail in rain or snow when you need them most.
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Inspect wiper arm connections weekly. Vibration from road conditions can loosen the connector nuts or cause the arm to slip on its post. A quick visual check and a slight tug on each arm during pre-trip takes 30 seconds and prevents a violation.
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Test both high and low wiper speeds. Some failures occur only at higher speeds or only intermittently. Running wipers for a few seconds in the yard gives you confidence before you roll onto the highway in wet conditions.
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Carry a spare wiper blade in your cab. If a blade fails between maintenance intervals, you can swap it roadside in under five minutes rather than risk citation or lose visibility in rain.