Parametric CAD has made inroads in transportation engineering in recent years. FreeCAD provides an excellent framework for the development of a free / open source CAD package for 3D parametric cad modelling of highways and related infrastructure. A broad view of the development of the FreeCAD Trails workbench for horizontal and vertical alignment design, 3D proof-of-concept and geomatics / surveys will be presented. The Trails workbench is being designed as an all-in-one workbench to provide tools for 3D highway design and modelling, from surveys / geomatics through alignment design and 3D models, including volumetric calculations. Integration with GIS is in its nascent stages as development efforts have been focused largely on stability and prototyping key tool sets and user interface elements.