Abstract: The years we are experiencing are often identified as those of the age of digital technologies, where "digital" is commonly associated with intelligence, efficiency, and convenience. The emergence of digital technologies has significantly impacted and transformed various aspects of our society compared to the past. In this panorama, some arising questions regard transportation infrastructure systems and, first of all, highway infrastructure. This research focuses on one central issue: how highways fit into this digital revolution. Actually, the work in this paper can be described as follows. Although there are many different theoretical model systems for the architecture of the digital twin, we have chosen to review the main body of research on the digital twin in highway infrastructure based on a relatively well-established modeling framework, the five-dimensional model of the digital twin. After discussing the components of the digital twin for highway infrastructure's five-dimensional model, the paper reviews some innovative technologies that make these items effective. In addition to this, the digital twin maturity level of highway infrastructure and the MBSE-based (model-based systems engineering) digital twin model for highway are also discussed in this paper. Therefore, the paper provides a bird's eye view of this extremely dynamic technology for a new system of intelligent highways and discusses some of their criticalities and strengths, allowing for the optimization and development of new transportation functions and services, improving the adaptability of highways to the digital revolution.