Worked on the tier4/scenario_simulator_v2 repository to enhance lane matching logic by implementing an absolute-distance-based approach for nearest lane selection. Addressed a bug where the previous method incorrectly identified the closest lane, leading to unreliable lane-level decisions for downstream planners. Utilized C++ and applied algorithm implementation skills to refactor the selection process, ensuring the system consistently chooses the truly nearest lane by sorting candidates based on absolute distance. Validated the fix through scenario simulations, confirming no regressions in related modules. This improvement increased the reliability and determinism of lane selection, streamlining debugging and supporting more robust software development practices.