where: W = number of 18-kip ESALs (equivalent single axle loads) Zr = standard normal variable (e.g., 1.28 for 90% reliability) S0 = overall standard deviation (e.g., 0.45) SN = structural number (a measure of pavement strength) p = pavement serviceability index (e.g., 2.5)
An effective AASHTO spreadsheet typically processes several critical engineering inputs: Design Traffic ( W18cap W sub 18 aashto flexible pavement design excel spreadsheet
Where: