IDOT pavement design uses the AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) methodology implemented in AASHTOWare Pavement ME Design software. Design inputs include traffic (ESALs), climate data, subgrade characterization (resilient modulus), and material properties. Design reliability: Interstate 95%, arterial 90%, collector 80%. Pavement type selection follows the IL Pavement Type Selection Policy.
References: AASHTO current edition, IL Standard Specifications, FHWA Technical Advisories, and applicable federal regulations (23 CFR). Contractors shall maintain current copies of all referenced standards on the project site.
Source: IDOT Highway Design Manual, 2024 Edition. Pages 21–22 of 37.