Violation code

392.2-SLML

State/Local Laws - Failure to maintain lane.

Unsafe Driving5Non-OOS· SMS Appendix A v3.20

392.2-SLML is a Dangerous Driving violation under 49 CFR §392.2-SLML. It falls in the Unsafe Driving BASIC with a severity weight of 5/10. Nationally it was cited 3,936 times in the last five years, with an OOS rate of 0.0%.

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National roadside inspection stats

as of 6/20/2026

Inspections

3,918

that found this code

Violations

3,936

total written

OOS rate

0.0%

0 OOS

Source: FMCSA roadside inspection data (last 5 years). The OOS rate is the share of these violations that led the officer to mark the driver or vehicle out of service.

Violation group: Dangerous Driving
Regulation §: 392.2-SLML
Severity weight: 5
Used in SMS: Yes
Status: Active
Updated: 6/20/2026

Last updated June 2026

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Notes

DSMS: Y | Comment: Added in 3.15 | Footnote: As of February 1, 2023, the violations in this table are included in SMS. Only violations cited on or after February 1 are included in SMS calculations. This update aligns SMS with how violations are being cited in a new software used for roadside inspections.

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Challenging 392.2-SLML through FMCSA DataQs

If this violation was written incorrectly, here are the angles trucking-safety managers use to contest it. Playbook: Unsafe Driving.

Relevant 49 CFR49 CFR § 392.2

Applicable operating rules

“Every commercial motor vehicle must be operated in accordance with the laws, ordinances, and regulations of the jurisdiction in which it is being operated. However, if a regulation of the Federal Motor Carrier Safety Administration imposes a higher standard of care than that law, ordinance, or regulation, the FMCSA regulation must be complied with.”

Common ways to challenge this code

Radar / lidar / scale calibration not produced
The state instrument used to measure speed or weight had no current calibration certificate, or one was never provided when requested.
Evidence that wins
- ✓FOIA / public-records request response from the citing agency
- ✓Calibration log expiration date if produced
- ✓Driver's contemporaneous note (e.g., independent dashcam speed)
Citation based on visual estimate only
The inspection report indicates the officer estimated speed visually rather than using a calibrated instrument.
Evidence that wins
- ✓Inspection report narrative copy showing "visual estimate" wording
- ✓Officer training records or pacing distance, if obtainable
Underlying citation adjudicated
The underlying state court adjudicated the citation as dismissed, reduced, or amended.
Evidence that wins
- ✓Certified court disposition with case number and date
- ✓Original citation copy

Common pitfalls — avoid these

⚠Submitting an uncertified court printout — DataQs requires the clerk-stamped version
⚠Forgetting that "guilty of a lesser charge" still counts as conviction — the violation may stay, just at reduced severity

⚡ Draft a challenge for 392.2-SLML →Read the DataQs guide first

More codes in Unsafe Driving

Same BASIC category — ranked by national citation volume

View all Unsafe Driving codes →

Other Dangerous Driving codes

Codes under the same FMCSA violation group

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Frequently asked questions about 392.2-SLML

What does violation 392.2-SLML mean?

392.2-SLML is the FMCSA roadside-inspection violation code for "State/Local Laws - Failure to maintain lane.", part of the Dangerous Driving group, cited under 49 CFR §392.2-SLML.

What BASIC does 392.2-SLML affect?

392.2-SLML falls under the Unsafe Driving BASIC in the FMCSA Safety Measurement System (SMS).

What is the CSA severity weight of 392.2-SLML?

392.2-SLML carries a severity weight of 5 out of 10. Higher weights indicate violations more closely tied to crash risk, and they count more toward a carrier's Unsafe Driving score.

Is 392.2-SLML an out-of-service (OOS) violation?

No. 392.2-SLML is not an out-of-service violation, so on its own it does not trigger an out-of-service order at the roadside.

How many CSA points does 392.2-SLML add to a carrier's score?

The point contribution of 392.2-SLML depends on its severity weight (5/10) multiplied by a time weight of 3, 2, or 1 based on how recent the inspection is. You can calculate the exact contribution with the CSA points calculator.

Can 392.2-SLML be challenged through DataQs?

Yes. If you believe 392.2-SLML was recorded in error, you can file a Request for Data Review (RDR) through the FMCSA DataQs system with supporting evidence. A successful challenge can remove or correct the violation on your record.

Keep going

CSA points calculator How to challenge a violation Draft a DataQs letter for 392.2-SLML Unsafe Driving BASIC Carrier CSA lookup CSA glossary