Road traffic crash trends at uncontrolled locations in Jaffna district (2014–2024): a pre-, during-, and post-covid-19 perspective with evidence-based engineering countermeasures

Abstract

Road traffic crashes remain a critical public health concern in Sri Lanka, with Jaffna District facing elevated risk driven by rapid post-conflict motorization and an ageing road network lacking adequate traffic control infrastructure. This study analyses 5,642 police-recorded crashes at uncontrolled locations in Jaffna District over a ten-year period (2014–2024), structured across three phases: Pre-COVID-19 (2014–2019), During COVID-19 (2020–2021), and Post-COVID-19 (2022–2024). A mixed methodology combining Equivalent Property Damage Only (EPDO) crash severity analysis, QGIS-based kernel density blackspot mapping, and systematic field intersection inventories were employed. A total of 3,398 crashes at uncontrolled locations were analyzed, and 22 blackspot junctions were confirmed across four priority road corridors: A009, AB016, AB018, and AB020. The pre-COVID-19 baseline annual EPDO averaged 2,223, declining to 1,725 during COVID-19, and partially recovering to 1,651 post-pandemic. The study found that 68.2% of crashes occurred at uncontrolled T-junctions and four-leg cross junctions, with angles, head-on, rear-end, sideswipe, and single-vehicle collisions accounting for over 85% of events. Field inventories revealed consistent deficiencies including absent road markings, insufficient sight distances, and no advance warning signs. Eight evidence-based engineering countermeasures are proposed — including stop sign packages for T-junction blackspots and mini roundabouts for four-leg junctions. International evidence indicates these measures could achieve a 40–75% reduction in fatal and serious injury crashes, supporting Sri Lanka's National Road Master Plan (2021–2030) and UN SDG 3.6.