§393.80 requires every CMV to be equipped with two rearvision mirrors, one mounted on each side, positioned so the driver has a clear view to the rear along both sides of the vehicle. The mirrors must be firmly attached and adjustable. Convex (wide-angle) mirrors may supplement but not replace the required §393.80(a) mirrors.
Severity weight
Severity weight 1 in the Vehicle Maintenance BASIC. The weight is low but a missing or broken mirror is a classic pre-trip catch; it also affects §391.41(b) driver-vision compliance if the driver cannot maintain rearward visibility.
What's commonly cited
- Side mirror broken or cracked in a way that distorts the rearward view.
- Mirror missing entirely after a curb-strike or low-clearance impact.
- Mirror so loose that it cannot hold a position — §393.80 requires firm attachment.
How to prevent it
- Pre-trip mirror check: verify position, security, and clarity of the reflecting surface.
- Replace mirror glass — not the whole housing — when the glass alone is cracked.
- Train drivers to report mirror damage immediately; a broken mirror at 0700 is a §392.7 pre-trip skipped item if the driver moves anyway.
How Roadworthy HQ helps
§393.80 findings logged in Roadworthy HQ link to the vehicle, attach to the DVIR pre-trip record, and retain the §396.9(d)(3) repair certification.