In seeking to improve traffic congestion and safety on roads and highways,there has been an increased interest in intelligent transportation systems(ITS).The emerging visible light communication(VLC)technology is a new candidate to enable wireless access in ITS.The purpose of this study is to present a comprehensive review of the current studies related to VLC.Since VLC facilitates illumination and data communication simultaneously,it reduces energy consumption significantly.Additionally,VLC is immune to electromagnetic inter-ference,provides high data security,and utilizes unregulated visible light spectrum,showing promise as a potentially cheaper alternative to existing radio frequency(RF)based technology.Moreover,recent advances in semiconductor materials and solid-state tech-nologies have enabled the development of efficient light-emitting diodes(LEDs)and laser diodes(LDs)which are used as transmitters in a VLC system.Although 10 s of Gbits/s data rate has been demonstrated in indoor VLC links,successful implementation of it in outdoor environments requires further research to overcome the challenges presented by envi-ronmental factors,unwanted lights,non-line of sight communication,directional radiation pattern,frequent fragmentation,and so on.Besides,in recent years,semiconductor LDs have been garnering more attention since they can transmit more data over longer dis-tances due to their high quantum efficiency and modulation bandwidth compared to LEDs.As a result,urban planners,policy-makers,transportation engineers,and vehicle manu-facturers are considering LD-based VLC to facilitate vehicle-to-vehicle and vehicle-to-infrastructure communication.Thus,this paper reviews and compares the most recent developments in VLC technologies,identifies their benefits and potential use in ITS ap-plications,discusses the probable barriers for their implementation in our existing trans-portation infrastructure,and suggests future research directions and recommendations to overcome these challenges.