They nonetheless allowed owner - operators to spend months at a time on road , often driving in teams of two ( one drove while the other slept ) .
Sleeping berths came into use as early as the 1920s , but they were often unsafe and uncomfortable .
They allowed owner - operators to spend months at a time on road , often driving in teams of two ( one drove while the other slept ) .
Sleeping berths came into use as early as the 1920s , but they were often unsafe and uncomfortable .