Protecting bridge maintenance workers from falls: Evaluation and selection of compatible fall protection supplementary devices

Falls from bridge decks are a common issue among highway and bridge maintenance workers. These workers generally rely on existing bridge guardrails for their protection against falls when working on bridge decks. Unfortunately, a large number of bridge guardrails do not provide the required barrier height of 107±8 cm (42±3 in.) for sufficient protection. To overcome this issue, a few departments of transportation (DOTs) have recently begun installing Fall Protection Supplementary Devices (FPSDs) on bridge guardrails - to temporarily increase the overall barrier height during work. However, many manufactured and marketed FPSDs are not compatible - or do not firmly attach onto every bridge guardrail. Therefore, workers are often tasked with assessing the compatibility of FPSDs with particular bridge guardrails before initiating work. Traditionally, this has been performed using an inefficient trial-and-error based approach - where potential FPSDs are procured, transported, and iteratively tested with a number of bridge guardrails. Apart from this inefficient testing procedure, current literature does not offer any guidance on the selection of efficient FPSDs based on the advantages they offer. Therefore, compatible FPSD systems that are not optimal for work efficiency, productivity, and safety are commonly adopted in practice. To resolve these challenges, the current research focused on identifying compatible FPSDs - that offer the most advantages - for 12 bridge guardrails that appear across 11,000 bridges in North Carolina. The study objectives were accomplished by (1) building virtual prototypes of existing bridge guardrails and FPSD systems and assessing compatibility in a virtual setting; (2) identifying desirable FPSD characteristics that can lead to improvements in work-efficiency, productivity, and safety (i.e., advantages); and (3) evaluating potential FPSD systems for each guardrail using the structured Choosing by Advantages (CBA) method - to identify FPSD systems that offer the most important set of advantages. The study addresses a nationwide safety issue experienced by all transportation agencies in the United States and beyond. It is expected that the findings will encourage more DOTs to adopt efficient fall protection measures and systems to protect their workforce.