Federal regulations limit how long commercial truck drivers can be behind the wheel without rest — for an obvious reason. A fatigued driver in a 40-ton vehicle is a public-safety risk in a way no other road user is. When those rules are broken, the consequences are often catastrophic. And when violations turn up in discovery on a truck case, they're some of the most powerful evidence a plaintiff can have.
This guide walks through the federal Hours of Service (HOS) rules, why violations happen even with sophisticated tracking, and how we use them to build cases. For the broader context, see our Texas Truck Accident Guide or our truck accident practice page.
01 — The federal rules.
HOS regulations are set by the Federal Motor Carrier Safety Administration (FMCSA) under 49 CFR Part 395. The most important provisions for property-carrying drivers (the 18-wheelers we handle most often):
- 11-Hour Driving Limit: A driver may drive a maximum of 11 hours after 10 consecutive hours off duty.
- 14-Hour Limit: A driver may not drive beyond the 14th consecutive hour after coming on duty.
- 30-Minute Break: A driver must take a 30-minute break after 8 cumulative hours of driving.
- 60/70-Hour Limit: No driving after 60 hours on duty in 7 days, or 70 hours in 8 days, depending on the carrier's operating schedule.
- 34-Hour Restart: Drivers can reset their 7/8-day clock with 34 consecutive hours off duty.
02 — The 11-hour rule.
The 11-hour limit is the headline rule and the one drivers and dispatchers think about most. After 10 consecutive hours off duty, a driver gets 11 hours of driving time — and that's the maximum, no exceptions for finishing the route, beating traffic, or making delivery windows. When discovery reveals a driver was still driving in hour 12 or 13, the violation is a strong indicator that fatigue contributed to the crash even if the driver wasn't visibly impaired.
03 — The 14-hour rule.
The 14-hour rule is less famous but more often violated. It says a driver cannot drive past the 14th consecutive hour after coming on duty, regardless of how much actual driving has been done. The point is to prevent split shifts that effectively keep a driver awake and working for 16+ hours. Carriers sometimes ask drivers to "extend just a little" to make a delivery window — and that's exactly when the catastrophic crashes happen.
The "just one more hour" problem.
The most common HOS violation we see in litigation isn't a driver who ignored the rules cold — it's a driver who was within the rules for most of a shift and then pushed the last hour or two to make a deadline. Carriers often know this is happening, accept it, or implicitly encourage it through delivery schedules that can't be met legally. When that pattern shows up in a series of trips for the same driver, it shifts the case from "the driver made a mistake" to "the company chose profit over safety."
04 — The 70/8 rule.
Long-haul drivers face cumulative limits across a week. Carriers using the standard 8-day schedule cap their drivers at 70 hours on duty over 8 days. Smaller carriers using a 7-day schedule cap at 60 hours. Drivers can reset the clock with a 34-hour restart period. Cumulative-limit violations show up most often in cases involving long-distance hauls and tight delivery schedules — the Texas-California and Texas-Midwest runs are common factual settings for our cases.
05 — Electronic logging devices.
Until 2017, drivers tracked HOS compliance with paper logbooks — which were widely falsified. The FMCSA's ELD mandate replaced paper logs with electronic logging devices that automatically record drive time, on-duty time, and rest periods.
ELD data is one of the most important pieces of evidence in any truck case where fatigue is potentially a factor. It can show:
- The driver's actual hours of service for the days leading up to the crash
- Pattern violations across previous trips
- "Edits" to the log — which sometimes reveal attempts to retroactively bring violations within compliance
- Cross-reference points to compare against fuel receipts, toll records, and dispatch logs
Like the truck's "black box" (ECM), ELD data needs to be preserved fast — carriers can retain only specific time periods, and policies vary.
06 — Why violations happen.
HOS violations are not random. They cluster around predictable economic pressures:
- Detention time at shippers and receivers. Drivers often wait hours to load or unload, eating into their on-duty time. When dispatch insists the load still has to be there by tomorrow, the driver pushes the rules.
- Pay-per-mile compensation. Most truckers are paid by the mile, not by the hour, so non-driving time is unpaid time.
- Just-in-time logistics. Modern supply chains are built on tight delivery windows that don't account for HOS limits.
- Driver shortage pressure. Carriers facing shortages sometimes lean on existing drivers to cover more.
- Bonuses for on-time delivery. Common, and a direct financial incentive to violate HOS rules.
07 — Pattern violations & gross negligence.
A single HOS violation, in isolation, is a regulatory issue. A pattern of violations across multiple trips — particularly when the carrier knew about them or should have — moves the case into gross negligence territory. That matters because gross negligence in Texas opens the door to punitive damages, which can substantially increase case value and which aren't available in ordinary negligence cases.
The discovery road to gross negligence runs through the carrier's safety records, prior FMCSA inspection results (visible on the public SAFER database), internal communications about scheduling pressure, and the carrier's response when drivers reported being "out of hours." If a carrier's response to HOS warnings was "push through it," that's evidence we want to find.
08 — How we prove HOS violations.
- Preservation letters. Within days of the crash, we send formal spoliation letters to the carrier requiring preservation of ELD data, dispatch records, fuel and toll receipts, and driver communications.
- ELD subpoena. Through litigation, we obtain the driver's ELD data for the days surrounding the crash and for the larger pattern context.
- Cross-reference. We compare ELD data against fuel receipts, toll records (TxTag, EZ Tag), bills of lading, GPS data, and dispatch records to identify discrepancies and edits.
- Expert testimony. Trucking-industry experts and human-factors specialists analyze the data and explain fatigue's contribution to the crash.
- FMCSA records. Prior inspection histories and safety scores on the SAFER database often reveal pattern carriers with chronic HOS issues.
The bottom line: HOS violations are common, they're consequential, and they're provable when the case is built fast. If you or someone you love was hurt in a truck crash, the time to preserve this evidence is now.