Urban Work-Zone Safety Beyond Crash Counts: A Source-Audited Analysis of Sign Loss and Corridor Monitoring in Medellín

Urban work-zone safety monitoring requires integrating operational records with road-incident information collected through different reporting systems. This study examines sign loss, data-source compatibility, and monthly associations between operational indicators and corridor-level incidents along Carrera 62 in Medellín, Colombia. A retrospective longitudinal observational design was applied to records covering November 2023–February 2025. The analysis included 288 supervision entries recorded on 278 dates, 96 sign-loss records representing 137 recorded stolen units, and incident summaries available for 13 of the 16 study months. The available monthly summaries contained 371 incidents, while three months with unavailable information were retained as missing rather than treated as zero. Recorded sign loss showed a positive monthly association with corridor incidents (Spearman rs=0.561; unadjusted p=0.046), although the association weakened after Holm adjustment (p=0.074). Supervision-entry count was negatively associated with incident counts (rs=−0.778), whereas the nighttime share of supervision entries showed a positive association (rs=0.582). A paired-month bootstrap for the sign-loss association yielded a 95% percentile interval from −0.073 to 0.926, and adjacent-month changes did not reproduce the positive relationship observed in the level-based comparison. Because traffic and pedestrian exposure, date-specific work-front records, and the event-level incident extract were unavailable, the analysis focuses on what the archived records can support for safety monitoring rather than on estimating exposure-adjusted risk or causal effects of roadworks or temporary traffic management. The findings highlight the importance of traceable data sources, dated work-front locations, explicit data-availability coding, exposure measures, and sign-restoration times for strengthening safety monitoring in urban work zones.