Roadside safety refers to the assessment and improvement of safety measures related to roadside environment, design, management, and objects. It encompasses factors such as road design, signage, markings, traffic control devices, and roadside features, and its goal is to reduce accident risk, minimize injuries, and enhance overall safety and comfort for road users. To comprehensively summarize roadside safety research progress, this review retrieved 1637 English papers published between 2000 and 2022, using the Web of Science Core Collection database. VOSviewer software was utilized to visualize and analyze the literature, conduct a situational analysis of publication, create knowledge maps of the main research hotspots and trends, and summarize research status, methods, systems, challenges, and trends in this field. Results showed an overall increasing trend in relevant research. The countries, institutions, and journals contributing most are the United States, the University of Nebraska, and the Transportation Research Record, respectively. Current research hotspots include evaluation of roadside safety and risk levels, factors influencing roadside safety and driving risks, drunk and drug-impaired driving in relation to roadside traffic accidents, frequency and severity of roadside accidents, and roadside safety assurance techniques and improvement strategies. Current modeling methods mainly consist of mathematical statistical analyses and data-driven modeling based on machine learning. Future research should focus on comprehensive quantitative mapping of influencing factors and evaluation criteria, establishing an active-guidance-based evaluation system and optimization strategy, improving the accuracy of computational problems and model construction, and exploring theories and technologies of intelligent transportation for roadside safety management and improvement.