Road signs are an essential component of a safe driving environment. Understanding road signs is vital to road safety. This paper reviews many earlier investigations into how well drivers understand road signs, considering ergonomic principles. Articles from 2012 to 2023, indexed by Web of Science, Scopus, Google Scholar, IEEE, Semantic Scholar, Science Direct, Cambridge Core, and JSTOR, were used to evaluate the literature on ergonomics and road signs comprehension. The analysis reveals that some evaluation techniques have been created to measure how well road signs are understood. Based on International Standard Organization (ISO, 3846 and 39001), 268 road signs were reviewed out of which, 112 (41.79 ) road signs are associated with lower comprehension scores and may pose a higher risk to road users who many not fully understand their meaning. 156 (58.21 ) road signs associated with higher comprehension scores and likely understood by road users. In conclusion, human traits, cognitive sign design and ergonomic principles are crucial for understanding and producing road signs. It was suggested that applying ergonomic ideas to the design of road signs can increase user comprehension. © 2023 Elsevier Ltd