Pavement Number (PN) Based Design
The PN-based design method is a simple, robust and reliable approach to determining the structural capacity of a planned pavement structure. The method uses a five-layer pavement system to determine an overall indicator of the long-term load spreading capacity of the combined pavement layers. This indicator is called the Pavement Number (PN) and is determined by multiplying the Effective Long Term Stiffness (ELTS) of each layer with the layer thickness. These products are then added for all layers above the subgrade and scaled to provide a number from zero to roughly 70, which is directly correlated with structural capacity.
The PN-based method was developed and calibrated using more than 20 pavement structures which had either been subjected to actual long term trafficking, or too controlled accelerated testing using the GDPTRW Heavy Vehicle Simulator (HVS) machine.