Classic tractor parts defination. Lesson 3

of spreading the total gross weight between the truck’s wheels, single axles, and grouped axles so that its imposed weight on the ground doesn’t hurt the quality of the roads and complies with the road federal regulations.
The standard vehicle weight regulations
These are the main standard vehicle weight rules:
Max single or steering axle weight - this is the axle of a vehicle that is controlled by the driver who manages the direction traveled by the vehicle, which is 12,000 to 20,000 depending on the state you are rolling.
Max legal weight limit - this is the max weight legal limit spread on any axle configuration without requiring a permit, which is 34,000 lbs on a tandem.
Max weight limit with a permit - this is the max weight legal limit on any axle configuration requiring a permit, which is 44,000 lbs on a tandem.
Maximum Gross Vehicle Weight - this is the total weight of the tractor plus the weight of the loaded semi-trailer, which is 80,000 lbs. 

for 53' trailer in combination with a tractor-truck is 80,000 lbs. The trick is that, sometimes, after loading, even though the truck’s gross weight may be under 80,000 lbs, it may still be overweight. How can that happen? That usually happens when the weight of the load is not equally spread on the drive and trailer axles.
Methods of redistributing the weight inside the trailer
In case when the truck is overweight on one of the axles, here are a few ways how to distribute the weight inside a trailer: 
Redistributing the weight back and forward between the different sets of axles.
Sliding the 5th wheel.  
Sliding the trailer tandem axles. 
The amount of fuel onboard and the fuel tanks placement may also affect the weight distribution inside the trailer. So, removing fuel may makes sense. 

refresh and rest. All rest areas can be used by drivers to stop and park.

to east, while even numbers run east–west with numbers increasing from south to north.

is divided into 4 time zones.
Eastern Time (EST/EDT)
Central Time (CST/CDT)
Mountain Time (MST/MDT)
Pacific Time (PST/PDT)
Alaska and Hawaii have their own time zones: Alaska Time and Hawaii Time respectively.