Several professional Excel-based tools are available for designing flexible pavements based on the AASHTO 1993 empirical method or the more modern AASHTOWare Pavement ME Design (Mechanistic-Empirical) methodology. These spreadsheets automate the complex iterations required to find the required Structural Number ( SNcap S cap N ) and final layer thicknesses. Recommended AASHTO Flexible Pavement Spreadsheets
She flipped to Tab 5: Drainage Coefficients (m₂, m₃). For the base layer in a wet climate with slow drainage, AASHTO said apply m = 0.9. That reduced her base contribution from 1.12 to 1.008. Now the total SN dropped to 4.208. Still above 4.2. Barely. aashto flexible pavement design excel spreadsheet
AASHTO Flexible Pavement Design Excel Spreadsheet: aashto flexible pavement design excel spreadsheet
[SN = a_1 D_1 + a_2 D_2 m_2 + a_3 D_3 m_3] aashto flexible pavement design excel spreadsheet