SierraSoft Roads is described as 'BIM software for the design of roads and highways'. There are three alternatives to SierraSoft Roads for Windows and Mac. The best alternative is Highroad. Other great apps like SierraSoft Roads are AutoCAD Civil 3D (Paid) and Bentley Inroads (Paid).
AutoCAD Civil 3D software is a Building Information Modeling (BIM) solution for civil engineering design and documentation. Civil 3D is built for civil engineers, drafters, designers, and technicians working on transportation, land development, and water projects.