A Digital Terrain Model (DTM) is a graphic network of 3D points and breaklines modeling the surface of the earth.
Typical scales are 1 inch = 100 feet and 1 inch = 200 feet for planning and preliminary
design and 1 inch = 50 feet for final design and construction.
DTMs are used to generate contours, determine drainage, estimate and calculate earthwork
quantities for the planning, design, and construction of transportation projects.
Digital terrain models with associated X, Y, and Z coordinate system are delivered to the customer.