When　analyzing　the　impact　of　vehicle　braking　on　a　bridge,　it　becomes　evident　that　the　bridge’s　deflection　increases　significantly　compared　to　when　a　vehicle　is　in　constant　motion.　The　magnitude　of　this　deflection　is　influenced　by　the　Vehicle-Bridge　Interaction　(VBI)　phenomena,　which　is　significantly　activated　by　road　roughness.　This　road　roughness　instigates　specific　dynamics　in　the　vehicle,　accentuating　the　VBI.　Our　study　introduces　a　probabilistic　model　to　quantify　this　amplification　factor　due　to　a　vehicle’s　hard　braking　at　the　bridge’s　mid-span　across　various　road　roughness　categories.　The　amplification　factor　is　defined　as　the　ratio　between　maximum　deflections　during　vehicle　braking　and　those　when　the　vehicle　is　at　a　consistent　speed.　It’s　estimated　considering　parameters　like　the　vehicle’s　mass,　velocity,　natural　frequency,　and　damping.　For　our　VBI　model,　we　utilized　the　finite　difference　method　to　discretize　the　coupled　governing　equations.　Here,　the　vehicle　is　represented　as　a　two-degree-of-freedom　system,　accounting　for　both　its　bouncing　and　pitching　motions.　The　model’s　computational　efficiency　facilitated　extensive　analyses　where　parameters　were　chosen　via　the　Latin　Hypercube　sampling　method.　Ultimately,　we　validated　our　model　outputs　against　real-world　bridge　displacement　measurements　under　varied　conditions.　©　2024　The　Author(s).