Maps contain abundant geospatial information, such as roads, settlements, and river networks, to name a few. The need to access this information to carry out analyses (e.g., in transportation, landscape planning, or ecology), as well as advances in software and hardware technologies, have driven the development of workflows to efficiently extract features from maps. The aim of this article is to provide a comprehensive overview of such methods to extract road features from raster maps. The methods are categorized based on the classes of techniques they employ (e.g., line extraction), as well as their subclasses (e.g., line tracing, Hough transform), the amount of user intervention required (e.g., interactive, automatic), the required data (e.g., scanned maps, contemporary vector data) and the produced results (e.g., raster‐based predictions, vector‐based results, attributes). Additionally, recent road extraction methods from overhead imagery, together with evaluation methods that will possibly benefit road extraction from raster maps, are reviewed. Furthermore, the evolution of this research field is analyzed over the past 35 years and the limitations of the current techniques, as well as possible future directions, are discussed.
