The Shell pavement design method is used in many countries for the design of new asphalt

Asphalt

Asphalt or , also known as bitumen, is a sticky, black and highly viscous liquid or semi-solid that is present in most crude petroleums and in some natural deposits, it is a substance classed as a pitch...

 road

Road

A road is a thoroughfare, route, or way on land between two places, which typically has been paved or otherwise improved to allow travel by some conveyance, including a horse, cart, or motor vehicle. Roads consist of one, or sometimes two, roadways each with one or more lanes and also any...

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In structural road design

Structural road design

Structural road design aims to ensure the road is strong enough for the expected number of vehicles in a certain number of years. The input of a calculation is the number expected of vehicles divided in groups and the number of years that the road has to function before the road structure has to...

, the main considerations consist of soil

Soil

Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

 parameter

Parameter

Parameter from Ancient Greek παρά also “para” meaning “beside, subsidiary” and μέτρον also “metron” meaning “measure”, can be interpreted in mathematics, logic, linguistics, environmental science and other disciplines....

s, parameters (thickness and stiffness) for the other road foundation materials, and the expected number of times a standard load will pass over. The output of the calculation is the thickness of the asphalt layer.