HOS Violations Mean Something Different Now. Most Brokers Haven't Caught Up.

Before 2019, roughly 40% of all hours of service violations cited during roadside inspections were form-and-manner logbook errors. Wrong date format. Missing line entries. Incorrect grid markings. The driver may have been fully compliant with actual driving time limits but filled out the paper logbook incorrectly, and the violation landed on the carrier's CSA record as an HOS compliance issue indistinguishable from a driver who ran 14 hours straight.

That era is over. Since the electronic logging device (ELD) mandate took full effect in December 2019, the ELD either records compliant hours or it does not. There is no "wrong date format" on an electronic log. The form-and-manner noise that inflated HOS BASIC percentiles for years has been largely eliminated from the data.

Hours of service violations in 2026 overwhelmingly represent actual driving-time exceedances, falsified records, or deliberate circumvention of federal rest requirements. A carrier with a high HOS Compliance BASIC percentile today is sending a materially different signal than the same percentile carried five years ago, because the violation composition underneath it has changed. Brokers still reading HOS data through a pre-ELD lens are underweighting one of the most reliable fatigue risk indicators in the federal safety dataset.

HOS Violations Quick Reference: What Each Type Signals

What Are Hours of Service Violations?

Hours of service violations are citations issued during roadside inspections or compliance reviews when a commercial motor vehicle driver is found to be operating in violation of federal driving-time limits, mandatory rest periods, or electronic logging requirements established by the Federal Motor Carrier Safety Administration (FMCSA).

HOS rules are the federal regulations that cap how long a commercial driver can operate a vehicle before mandatory rest. The core limits for property-carrying drivers: a maximum of 11 hours of driving within a 14-hour on-duty window, after 10 consecutive hours off duty. A 30-minute break is required after 8 cumulative hours of driving. A 34-hour restart resets the weekly 60/70-hour clock. For the full 2026 HOS rules reference, including the short-haul exception and adverse driving conditions provision, see our dedicated guide.

When an inspector finds a driver operating outside these limits during a roadside inspection, the violation goes on the carrier's record under the HOS Compliance BASIC. The carrier's HOS percentile reflects these violations weighted by severity and recency over a 24-month window, compared against similar-sized peers.

Why HOS Violations Matter More Than Most Brokers Think

Fatigued driving is a contributing factor in an estimated 13% of large truck crashes that result in fatalities, according to the National Highway Traffic Safety Administration's (NHTSA) Large Truck Crash Causation Study. That figure likely understates the real contribution because fatigue is difficult to establish definitively in crash investigations. Unlike alcohol or drug impairment, fatigue leaves no measurable trace at the scene.

HOS violations are the closest proxy the federal data system has for fatigue exposure. A carrier whose drivers consistently exceed driving time limits is a carrier whose drivers are consistently operating while tired. The connection between the violation and the risk it predicts is more direct than almost any other BASIC category. Unsafe Driving violations (speeding, reckless driving) are observed behaviors. Vehicle Maintenance violations are equipment conditions. HOS violations are a measure of how much rest the driver did or did not get before operating a 40-ton vehicle. The link to crash risk is causal, not just correlational.

How the ELD Mandate Changed What HOS Violations Mean

The ELD mandate, which required all carriers subject to paper log requirements to use certified electronic logging devices by December 16, 2019, fundamentally changed the composition of HOS violation data. Understanding this shift is necessary to read the data correctly.

Before ELD (Pre-December 2019)

Drivers maintained paper logs. Inspectors checked these logs during roadside inspections and commonly found:

1. Form-and-manner errors (severity weight 1 to 3): Incorrect date, missing trailer number, wrong total miles, incomplete grid markings. These violations reflected sloppy paperwork, not necessarily unsafe driving hours.
2. Falsified logs (severity weight 10): Deliberate alteration of driving times to conceal HOS exceedances. Paper logs made falsification simple because the log was whatever the driver wrote.
3. Actual driving-time exceedances (severity weight 5 to 7): Real violations where the driver operated beyond legal limits.

The problem: form-and-manner errors flooded the HOS BASIC with low-severity noise. A carrier could have an elevated HOS percentile built entirely on paperwork mistakes that had zero connection to driver fatigue.

After ELD (Post-December 2019)

The ELD records driving time automatically based on vehicle movement. The log is either compliant or it is not. Form-and-manner errors dropped dramatically because the device formats the data correctly.

What remains in the HOS violation data:

1. Driving-time exceedances are now the dominant violation type. The ELD proves the driver exceeded the 11-hour or 14-hour limit because the device recorded it.
2. ELD malfunctions and tampering replaced some falsification citations. Carriers that allow drivers to operate with malfunctioning ELDs beyond the 8-day repair window receive citations that signal the same disregard for the rules.
3. Unassigned driving time violations catch situations where driving occurred but was not attributed to a logged driver. This is the post-ELD version of log falsification.

The bottom line for vetting: a carrier with a high HOS BASIC percentile in 2026 has a data problem that is more real, more directly connected to fatigue risk, and more reliable than the same percentile would have been before 2019. If you are a broker still discounting HOS scores because "it used to be mostly paperwork stuff," update your model. The paperwork stuff is gone.

How HOS Violations Affect a Carrier's CSA Score

HOS violations feed into the HOS Compliance BASIC, one of seven Behavior Analysis and Safety Improvement Categories in FMCSA's Safety Measurement System. The HOS Compliance BASIC has an intervention threshold of 65%, meaning FMCSA begins enforcement escalation when a carrier's percentile exceeds this level.

The HOS BASIC uses the same three-layer scoring methodology as all other BASICs:

1. Collect all HOS-related violations from roadside inspections and investigations within the most recent 24 months.
2. Apply severity and time weighting. Each violation carries a severity weight (1 to 10, see the reference table above). Newer violations receive higher time weights: 3x for the first 6 months, 2x for 6 to 12 months, 1x for 12 to 24 months.
3. Compare the weighted score against peers. FMCSA groups carriers by inspection count and ranks them within the group. The result is a percentile from 0 to 100 where lower is better.

A single "falsifying records of duty status" citation carries a severity weight of 10, the maximum. With a 3x time weight in the first 6 months, that one violation contributes 30 points to the carrier's raw HOS measure. For a small carrier with 5 inspections, a single falsification citation can push the HOS BASIC from the 20th percentile to the 80th overnight. Use the BASIC Score Decoder, which shows the percentile alongside the inspection count and individual violation breakdown, to see whether an elevated score is built on a single high-severity event or a pattern of repeat offenses.

The 65% Threshold and What Triggers It

Because FMCSA's research shows a strong statistical link between HOS violations and crash involvement, the intervention threshold for HOS Compliance sits at 65%, the same as Unsafe Driving and the Crash Indicator. The other four BASICs (Vehicle Maintenance, Driver Fitness, Controlled Substances, Hazmat) use 80%.

The lower threshold means FMCSA takes HOS violations more seriously than Vehicle Maintenance or Driver Fitness violations in terms of enforcement prioritization. It also means the margin between "fine" and "flagged" is narrower. A carrier at 60% HOS is 5 points from intervention. The same carrier at 60% Vehicle Maintenance has 20 points of headroom.

For brokers: treat the 65% threshold as the maximum you should tolerate, not the level at which concern begins. Many brokerages internally flag carriers above 50% in any BASIC with a 65% threshold. Waiting for FMCSA to take action before you react means waiting for a carrier to accumulate a significant pattern of fatigue-related violations.

Which HOS Violations Predict Real Risk (And Which Are Noise)

Not all HOS violations carry equal weight for vetting decisions. The violation type, the context, and the pattern matter more than the count.

High-Risk Violations (These Should Change Your Decision)

Falsifying records of duty status (severity 10). This is not a mistake. This is deliberate deception by the driver, often with the carrier's knowledge or encouragement. A carrier with falsification citations has drivers who are actively concealing how long they have been driving. The connection to fatigue-related crash risk is direct and unambiguous.

Driving beyond the 11-hour limit (severity 7), repeatedly. A single 11-hour exceedance might be a planning error or an unexpected delay. Three or more within 12 months indicates a systemic problem: unrealistic dispatch schedules, driver pressure to push hours, or a safety culture that treats HOS limits as suggestions. Cross-reference with the carrier's inspection history to see whether the same driver or multiple drivers are involved.

Operating with a disabled or malfunctioning ELD beyond 8 days (severity 5). FMCSA allows 8 days to repair a malfunctioning ELD. Beyond that window, the carrier has chosen not to fix it. A working ELD is the only mechanism that prevents a driver from running illegal hours without detection. A carrier operating without one has removed the safeguard.

Lower-Risk Violations (Context Required)

30-minute break violation (severity 5). The 30-minute break requirement after 8 cumulative driving hours is the most commonly cited HOS violation in the post-ELD era because it is the easiest to exceed by a small margin. A driver who drives 8 hours and 12 minutes before stopping technically violated the rule. The fatigue risk of missing a 30-minute break by 12 minutes is negligible compared to an 11-hour exceedance. One 30-minute break violation in 20 inspections is noise. Five in 20 inspections suggest a carrier that does not build break time into route planning.

No record of duty status for the current day (severity 5). This can mean the driver forgot to log on, the ELD had a temporary malfunction, or the driver was trying to avoid recording hours. A single occurrence is ambiguous. Repeated occurrences on the same carrier are not.

The Pattern That Matters Most

The single strongest HOS risk signal is not any individual violation type. It is the combination of HOS violations and Unsafe Driving violations on the same carrier. A carrier at the 60th percentile in both HOS Compliance and Unsafe Driving has drivers who are tired AND driving aggressively. That combination is the highest-risk profile in the CSA dataset for predicting future crash involvement. When you see both BASICs elevated on the same carrier, the signals are reinforcing each other, not independent.

A Worked Comparison: Two Carriers at the 68th Percentile

Carrier A has an HOS Compliance BASIC at the 68th percentile based on 42 inspections. The violation breakdown: fourteen 30-minute break violations (severity 5 each), scattered across 12 months, involving 8 different drivers. No driving-time exceedances. No falsification. The carrier's Unsafe Driving BASIC sits at the 18th percentile.

Carrier B has an HOS Compliance BASIC at the 68th percentile based on 15 inspections. The violation breakdown: two 11-hour driving limit exceedances (severity 7), one 14-hour window violation (severity 7), and one falsification of records citation (severity 10), all within the last 8 months. The carrier's Unsafe Driving BASIC sits at the 55th percentile.

The percentile is identical. The risk profile is not even close.

Carrier A has a scheduling problem. Their drivers are not building 30-minute breaks into their route timing. That is a dispatch process issue that can be fixed with better trip planning software and a memo to drivers. The absence of any driving-time exceedance and a low Unsafe Driving score suggests the drivers are otherwise compliant and careful.

Carrier B has a safety culture problem. Two driving-time exceedances plus a falsification means at least one driver was not just tired but actively hiding it. The elevated Unsafe Driving score suggests the fatigue is showing up in driving behavior, not just log data. Four high-severity violations across only 15 inspections means the sample is small but the signal density is high.

A broker who rejects both carriers because "68% is above our 50% threshold" loses access to Carrier A, who has a fixable process issue. A broker who approves both because "68% is below the 80% Vehicle Maintenance threshold" (confusing BASIC thresholds) takes on Carrier B's compounding risk. Reading the violations underneath the percentile is the difference between these outcomes.

How Long Do HOS Violations Stay on Your Record?

HOS violations affect a carrier's HOS Compliance BASIC percentile for 24 months from the inspection date. The time-weighting schedule is the same as all other BASICs: full weight (3x) for months 0 to 6, two-thirds weight (2x) for months 6 to 12, and one-third weight (1x) for months 12 to 24. After 24 months, the violation drops from the BASIC calculation entirely.

For carriers working to improve their HOS scores, the practical implication: a falsification citation (severity 10, time weight 3x) contributes 30 raw points in the first 6 months. By month 12, that same citation contributes 10 points. By month 18, it contributes 3.3. The decay is steep. A carrier that addresses the root cause and accumulates clean inspections will see meaningful percentile improvement within 6 to 12 months.

The violation data itself remains visible on the carrier's inspection record after it drops from BASIC scoring. Brokers reviewing historical inspection records can still see violations older than 24 months, but those violations are no longer affecting the carrier's percentile ranking.

How HOS Violations Affect Insurance Rates

Insurance underwriters weigh HOS violations heavily because of their direct link to fatigue and crash risk. A carrier with an elevated HOS BASIC percentile typically pays more for liability coverage, and the premium impact compounds alongside other violation categories rather than being evaluated in isolation.

Underwriters pay particular attention to:

1. Falsification citations. A single falsification on a carrier's record can trigger a manual underwriting review, premium surcharge, or non-renewal notice. Underwriters view falsification as evidence that the carrier's safety culture tolerates illegal behavior.
2. The HOS and Unsafe Driving combination. Carriers with elevated scores in both categories face the steepest premium increases because the data pattern matches the profile most strongly associated with future crash claims.
3. Trend direction. A carrier whose HOS percentile is declining (improving) gets different treatment than one whose percentile is climbing, even if the current number is the same. Underwriters look at 12-month and 24-month trend data, not just the snapshot.

For small carriers, the insurance cost of a high HOS BASIC can exceed the cost of any FMCSA enforcement action. A premium increase of $3,000 to $8,000 per year on a 5-truck fleet translates to $600 to $1,600 per truck, which comes directly out of operating margin on every load.

Frequently Asked Questions

What happens if a trucker violates hours of service?

The driver receives a violation citation on the roadside inspection report, which goes on the carrier's FMCSA record under the HOS Compliance BASIC. If the violation is severe enough, the driver may be placed out of service at the inspection site and prohibited from driving until they have taken the required rest period. The carrier's HOS BASIC percentile increases, affecting their CSA score, insurance pricing, and visibility to brokers. Repeated violations can trigger FMCSA enforcement escalation including warning letters, targeted inspections, and compliance reviews.

How do HOS violations affect CSA scores?

HOS violations feed directly into the HOS Compliance BASIC, one of seven categories in FMCSA's Safety Measurement System. Each violation carries a severity weight (1 to 10) and a time weight based on recency. The weighted total is compared against similar-sized carriers to produce a percentile from 0 to 100. The HOS Compliance BASIC has a 65% intervention threshold, the same as Unsafe Driving, reflecting FMCSA's research linking HOS violations to crash risk. A carrier above 65% faces progressive enforcement.

How long do HOS violations stay on record?

HOS violations affect the carrier's BASIC percentile for 24 months from the inspection date. They carry full weight for months 0 to 6, two-thirds weight for 6 to 12 months, and one-third weight for 12 to 24 months. After 24 months, the violation drops from the BASIC calculation entirely. The violation record itself remains visible on the carrier's historical inspection data beyond the 24-month scoring window.

Do HOS violations affect insurance rates?

Yes, and often significantly. Insurance underwriters use HOS BASIC data when pricing liability policies. Carriers with elevated HOS percentiles pay higher premiums. Falsification citations are particularly damaging because underwriters treat them as evidence of willful non-compliance. The premium impact is compounded when HOS violations appear alongside elevated Unsafe Driving scores, which is the combination most strongly associated with future crash claims.

What is the most common HOS violation?

The 30-minute break violation (failure to take a 30-minute break after 8 cumulative hours of driving) is the most frequently cited HOS violation in the post-ELD era. It is also the lowest-risk HOS violation in terms of fatigue correlation, because missing a 30-minute break by a small margin does not carry the same danger as exceeding the 11-hour driving limit. Despite being common, a single 30-minute break citation carries a severity weight of 5 out of 10.

Can a carrier be shut down for HOS violations?

Not directly from the violations alone. High HOS BASIC percentiles trigger FMCSA enforcement escalation (warning letters, targeted inspections, investigations) but cannot independently result in an operations shutdown. However, if an investigation triggered by elevated HOS scores uncovers broader compliance failures, FMCSA can issue an Unsatisfactory safety rating that requires the carrier to cease operations within 60 days. The violations open the door. The investigation determines what is behind it.

Why did HOS violations change after the ELD mandate?

Before the ELD mandate (fully effective December 2019), a large portion of HOS violations were paper logbook form-and-manner errors: wrong date formats, missing entries, incomplete grids. These reflected record-keeping sloppiness, not actual driving-time exceedances. Electronic logging devices eliminated most form-and-manner errors because the device formats data automatically. Post-ELD HOS violations overwhelmingly represent real driving-time exceedances, falsified electronic records, or ELD equipment non-compliance. The data is now a more reliable indicator of actual fatigue risk.

What is the difference between an HOS violation and an ELD violation?

An HOS violation is a citation for exceeding federal driving-time or rest-period limits (e.g., driving beyond 11 hours). An ELD violation is a citation for non-compliance with the electronic logging device rule itself (e.g., operating without a registered ELD, failing to transfer data to an inspector, using a non-certified device). Both feed into the HOS Compliance BASIC. The distinction matters because an ELD violation does not necessarily mean the driver exceeded driving-time limits; it means the device used to monitor compliance was non-functional or non-compliant.

The Signal That Changed

Before 2019, a broker could reasonably discount an elevated HOS BASIC because the data was contaminated with paperwork violations that said nothing about whether drivers were actually tired. That discount no longer applies. The noise has been stripped from the dataset.

A carrier at the 68th percentile in HOS Compliance today has a pattern of real driving-time violations recorded by a device that does not make form-and-manner mistakes. Whether those violations are 30-minute break technicalities or 11-hour exceedances with falsified records, the violation detail underneath the percentile tells you which. Pull the BASIC score breakdown. Read the violation types. Check whether Unsafe Driving is elevated on the same carrier. The percentile gets you to the question. The violation detail gives you the answer.