A　measured　fatigue　load　model,　tailored　for　the　Beijing-Tianjin-Hebei　region,　was　developed　using　dynamic　weighing　system(WIM).　In　addition,　fatigue　experiment　were　performed　on　orthotropic　steel　bridge　decks.　The　findings　of　this　study　reveals　that　fatigue　crack　tend　to　initiate　at　the　weld　toes　between　deck　and　U-rib,　developing　along　the　thickness　direction　of　deck.　the　stress　near　the　fatigue　crack　significantly　decreases　after　redistribution,　resulting　in　a　reduced　bearing　capacity　of　the　structure.　Furthermore,　the　position　of　the　fatigue　crack　suggests　that　welding　residual　stress　has　a　crucial　role　in　the　structural　fatigue　failure　process.　©　2023　SPIE.