Policy-driven life-cycle emissions and climate resilience of highway pavements: an LCA-optimization and scenario analysis

• Integrated LCA + climate deterioration + maintenance optimization for 2025–2065 (ΔT +2.3 °C; +20 % hot days). • BAU emissions: raw materials 45 %, construction 30 %; baselines ∼300 (asphalt) and ∼180 (concrete) tCO₂e·km⁻¹.. • Maintenance optimization cuts emissions (−25 % asphalt, −17 % concrete) and life-cycle costs (−22 %, −18 %). • Policy/actions: Moderate ∼20 % cuts; High >40 % cuts & −18 % net cost; adopt PG upgrades, recycled content, warm-mix. This study quantifies the environmental and economic implications of highway pavement construction and management in Jordan’s arid and semi-arid regions and evaluates policy-relevant adaptation pathways for 2025–2065, linking pavement engineering decisions to transportation-system sustainability and reliability. We couple a process-based life-cycle assessment (LCA) with a climate-driven deterioration–maintenance optimization model using projected stressors (+2.3 °C mean warming, +20 % extreme-heat days >40 °C, and higher rainfall variability). Under Business-as-Usual (BAU), phase contributions to total life-cycle emissions are: raw materials 45 %, construction 30 %, transport 15 %, maintenance 7 %, and end-of-life 3 %. Baseline emissions equal ∼300 tCO 2 e km −1 (asphalt) and ∼180 tCO 2 e km −1 (concrete). Optimization reduces emissions to ∼225 tCO 2 e km −1 (–25 %) and ∼150 tCO 2 e km −1 (–17 %), while lowering life-cycle costs by 22 % (asphalt) and 18 % (concrete). Policy packages amplify benefits: a Moderate Sustainability pathway reduces emissions by ∼20 % versus BAU, while a High Sustainability pathway achieves >40 % reduction and yields an 18 % net cost saving over 40 years despite 15–25 % higher upfront costs. Climate stress increases damage rates (asphalt 0.015 → 0.019 y −1 ; concrete 0.008 → 0.011 y −1 ), raising thermal cracking by 18 % and moisture-driven rutting by 15 %. Spatially, emissions are lowest in the Jordan Valley and highest in the Northern Highlands/Eastern Desert due to terrain and haul distances. Findings translate into actionable transport-policy levers—performance-grade upgrades, minimum recycled-content mandates, broad warm-mix adoption, and regionalized specifications—supporting lower-carbon, more climate-resilient networks with an estimated ≈30 % resilience/structural integrity gain under fiscally viable investment strategies.