General Hours of Service Guidelines

Driving Hours Per Week 2

The work week starts after the last legal reset. For example, if you begin at 1 a.m. on Monday, then your 168-hour work week continues until 1 a.m. the following Monday.
Each duty period must begin with at least 10 hours off-duty.
Drivers may work no more than 60 hours on-duty over seven consecutive days.
Drivers may be on duty for up to 14 hours following 10 hours off duty, but they are limited to 11 hours of driving time.
Drivers must take a mandatory 30-minute break by their eighth hour of coming on duty.
The 14-hour duty period may not be extended with off-duty time for breaks, meals, fuel stops, etc.
Drivers can restart the 7-day period once every 168-hour work week. This entails taking at least 34 consecutive hours off with two consecutive periods of 1 a.m. to 5 a.m.

Aug 28, 2017 - In other words, drivers have a limited number of hours they can be ON-Duty per cycle (week). Drivers cannot drive after they have reached.