Author Description

Culverts, conduits that facilitate passage of water beneath roadways and other structures, represent important components of infrastructure systems, helping to drain, direct or divert surface water and prevent the disruption of roadways. Their efficient inspection and maintenance is thus critical to safe operation of Indiana's transportation infrastructure. Although approximately 25% of culverts associated with INDOT managed roadways are inspected each year, inspectors face many challenges determining the actual condition of culverts, which can vary substantially in material type, form, length, depth of cover, accessibility, and age. This study was therefore performed to understand and synthesize technical culvert inspection alternatives with a focus on identifying and prioritizing readily available solutions.Research revealed that no standard inspection guidelines exist for small culverts, and that inspection practices vary significantly across states. DOT survey results indicate that DOTs primarily rely on visual examination conducted by field personnel, often from the open ends of the culvert, limiting the range of flaws and failure modes that can be identified, and the desired early warning benefits of inspection. While a range of technologies exist to facilitate inspection, most methods apply to only a limited set of culvert materials and operating conditions. This study thus provides a ranked recommendation of readily available culvert inspection solutions, segmented according to their applicability to varying culvert conditions and inspection needs. Techniques involving mobile visual camera systems and multi-sensing modes stand out for their potential to provide insight into the condition of a variety of culvert types at moderate cost.