For all turning vehicles, the rear wheels follow a shorter path than the front wheels. The longer the vehicle, the greater the difference. This is why truck drivers must often swing wide to complete a right turn. When you follow a truck, look at its turn signals before you start to pass. If you think the truck is turning left, wait a second and check the turn signals again. The driver may actually be turning right.
Large commercial truck and bus drivers sometimes need to swing wide to the right to safely make a left turn. They cannot see cars directly behind or beside them. Trying to squeeze in between the commercial vehicle and the curb is an invitation to disaster!