Moving to Model-Based Design By creating a road model instead of multiple, unrelated CAD drawings, you are developing a single data set from which all project documents are generated, improving coordination between the various work products and disciplines. For example, if you move the road, other elements such as profiles, cross sections, parcels, and daylight points all update automatically - instantaneously (see Figure 1). The digital design data generated from the model not only supports design and construction phases, but can also be used in downstream project phases to support the complete infrastructure lifecycle.  Fig 2 Process support for the total infrastructure lifecycle With a model-based approach, the amount of design information is consistent with the design process stage. A road representation, for example, may be a single centerline (during planning); a complete centerline, edge of pavement, shoulders, and right-of-way (late pre-design, design documentation); and a fully detailed road model (construction phase), without reentry or multiple inputs. The centerline object is simply modified and expanded to contain the next level of design information and detail consistent with the current phase of the project or that required by the project team member making the change. And the data model evolves accordingly; a design phase transition no longer means starting from scratch with new drawings and deliverables. This evolution reduces the possibility of coordination errors and makes graphic representation of objects consistent throughout the design deliverable set. Benefits for Designers and Engineers For designers and engineers, model-based design enhances project quality through improved coordination not only among plans, profiles, aspects, and take-offs but also between disciplines. For example, when the engineering model is shared across disciplines, you can use 3D functionality to easily identify interferences between sewer and water lines, drainage plans, street intersections, and more. Because all disciplines work from the same model, interdisciplinary coordination is improved and problems can be resolved before construction, reducing the cost and time required for rework. Perhaps the most significant benefit of model-based design is the usefulness of the digital design data throughout the infrastructure lifecycle |