How long can a semi truck travel for?

Current log regulations permit a driver to drive for 11 hours (within a 14 hour period), after which, they're required to take a 10 hour break. Their average speed is dependent on the state - each state has an average speed they'll accept in a logbook. In states like Texas, New Mexico, Arizona, and Colorado, which have 75 MPH speed limits, a truck driver can log an average of 68 MPH. In California, on the other hand, drivers are only permitted to log an average of 54 MPH.