Most truck-crash defences do not argue that the driver was fine. They argue that nobody can prove he was not. The hours-of-service rules exist to remove that argument, because they turn fatigue into a number.
The limits that apply to property-carrying drivers
| Limit | Rule | Citation |
|---|---|---|
| Off duty first | 10 consecutive hours off duty before driving | 49 CFR 395.3(a)(1) |
| Driving limit | 11 hours of driving within the duty window | 395.3(a)(3)(i) |
| Duty window | no driving after 14 consecutive hours on duty | 395.3(a)(2) |
| Break | 30 minutes after 8 cumulative hours of driving | 395.3(a)(3)(ii) |
| Weekly limit | 60 hours in 7 days, or 70 in 8 days | 395.3(b) |
| Restart | 34 consecutive hours off resets the week | 395.3(c) |
Two details that matter in practice:
The 14-hour window is not extended by breaks. Lunch, waiting at a dock, a nap — none of it pushes the window back. A driver who starts at 6am may not drive after 8pm, regardless of how much of that time was spent waiting.
“On duty” includes more than driving. Loading, inspections, paperwork and yard work all count toward the 14 hours, which is why a driver can be legal on driving time and still outside the window.
How this becomes evidence
The limits themselves are not the case. The case is whether the driver was inside them — and that is recorded.
An electronic logging device captures driving time, duty status changes and location. The engine control module captures speed, braking and engine hours. Together they answer the questions a jury actually cares about:
- How long had the driver been on duty when the crash happened?
- When did he last take a 10-hour break?
- How many hours in the last seven days?
- Was the vehicle speeding, and was it braking?
If those records exist, the case is largely arithmetic. If they have been overwritten, the argument becomes about credibility — which is a much worse place to be.
Why the six-month rule is not enough
Federal regulations require a carrier to keep a backup copy of ELD records for six months (49 CFR 395.22(i)(1)). Six months sounds generous until you remember that the two-year filing deadline runs far longer, and that a claim often is not evaluated until months after the crash.
Six months of retention is a compliance floor. It is not a guarantee that the data relevant to your crash is preserved, and it does not cover dashcam video or telematics at all.
That is why the preservation demand goes out in the first week, not the sixth month.