Traffic & Reliability
Design ESALs over the analysis period and reliability parameters.
80 kN equivalent single-axle loads
50–99.9; 95 for urban arterials
0.40–0.50 (flexible)
Serviceability
Initial (pₒ) and terminal (p_t) PSI; ΔPSI is computed automatically.
4.2 typical AC
2.0–2.5
ΔPSI (computed)
1.70
Subgrade
Effective resilient modulus of the roadbed soil.
Use CBR → Mᴿ helper if you only have CBR
Layer Coefficients & Moduli
AASHTO 93 structural-layer coefficients aᵢ and indicative moduli Eᵢ.
0.40–0.44
0.10–0.14
0 to skip
Drainage Coefficients
mᵢ adjusts unbound layers for moisture/drainage quality (0.40–1.40).
usually 1.0
Minimum Layer Thicknesses
Constructability minimums (mm); design rounds up to 5 mm.
Results
Z_R
-1.645
SN required
4.79
SN provided
5.46
log₁₀ W₁₈ (predicted)
7.103
Asphalt (D₁)
165 mm
Contribution SN = 2.86
Base (D₂)
355 mm
Contribution SN = 1.96
Subbase (D₃)
150 mm
Contribution SN = 0.65