[1] In many countries, drivers are subject to work-time regulations which limit the amount of time they can drive before taking a mandated minimum rest period.
Many drivers chose to sleep in the cab or cabin of their trucks rather than pay for a roadside motel.
Truck manufacturers took notice of this and began developing tractor units with extended cabs to provide a sleeping area for drivers.
Work-time regulations apply in the United States,[2] Europe,[3] Australia[4] and in other parts of the world.
[5] They nonetheless allowed owner-operators to spend months at a time on road, often driving in teams of two[6] (one drove while the other slept).