Hours of Service (HOS)

What Is Hours of Service (HOS)?

Hours of Service (HOS) refers to federal regulations governing how many hours a commercial truck driver can drive and work before being required to rest, designed to reduce fatigue-related accidents.

How Do HOS Rules Work?

In the US, HOS rules limit drivers to a maximum number of driving hours within a duty window (commonly an 11-hour driving limit within a 14-hour on-duty window), followed by a mandatory rest period, with additional weekly limits and required longer breaks. Compliance is tracked electronically via Electronic Logging Devices (ELDs) required on most commercial trucks.

Why HOS Matters

HOS limits directly constrain how far a truckload shipment can travel in a single day, and drivers running low on available hours can force unplanned stops that add a day or more to a delivery. Understanding HOS constraints is essential for realistic transit time planning on longer truck routes, rather than assuming a truck can simply drive straight through.