The CEDRA Corporation's CEDRA-AVland software extension to ArcGIS offers the engineering community a new technological approach to roadway and site design applications. Tightly integrated with Esri's ArcGIS software suite, CEDRA-AVland is a design system that integrates the various aspects of land morphology via a common geodatabase using the ArcGIS Desktop software products as the interactive graphics processor. With it, the designer can

• Develop a complete annotated topographic basemap for a design project.
• Design site geometrics, roadways, drainage systems, wastewater collection–transport facilities, and water distribution networks and final grading.
• Draft final design drawings.
• Provide bidirectional communication with ArcGIS for communitywide inventory–design–construction–management of the associated facilities.

CEDRA-AVland is based on the premise that (1) design itself is the primary function of the engineering design process of a project as a whole entity that interfaces with the geodatabase and that (2) drafting should be a direct by-product thereof. CEDRA-AVland supports both the U.S. customary and International System (SI) units of measure.

The design of a land morphologic (roadway or site design) project requires the provision of an accurate base topographic map. ArcGIS Desktop provides a variety of means for creating such a map, and the ArcGIS Survey Analyst extension provides the various survey control points that may be needed. Both may be accessed with CEDRA-AVland. Thus, if all required information is available in a central repository database, engineers can view and/or download the data into a map document file (see main story above).

If such information is not readily available, the engineer can create a base topographic map by importing radial, cross sectional, and/or regular or irregular grid survey field information and perform any required geometric operation including traverse adjustment, deed transcription, and contour generation to the precision required by the engineering project. Such field information may then be used to update the topographic basemap of a municipality.

In preparing the design drawings of a project, it is common practice to describe existing features within the region of the design project both symbolically and textually with labels. A multitude of special symbols has been introduced to accommodate feature symbology. Although feature labels may be introduced adjacent to the respective symbols, CEDRA-AVland can annotate features along, and offset from, a survey baseline or design centerline. This approach leaves the plan sheet area, within the confines of a new design, available for construction information. This form of base survey map preparation is common among many engineering design offices.

With the topographic map mass generated for the design project, the engineer identifies various existing control points and uses the COGO functionality built into CEDRA-AVland to introduce additional control points, lines, and/or buffer zones that may dictate the orientation of the project design. Once these controls have been introduced, the engineer utilizes the specialized commands to interactively design the roadway centerlines (i.e., horizontal alignments). CEDRA-AVland enables the engineer to dynamically modify horizontal alignments, thereby providing the designer a means to visually detect and avoid potential interferences. Once positioned as desired, alignments may be stationed by the program at specified station intervals and at points of curvature, and pavement ribbons and right-of-way lines may be mass generated at specified offsets in accordance with prespecified design control or local zoning requirements.

With a horizontal alignment set, the engineer defines the profile of the alignment. To do this, the engineer extracts an existing ground profile along the alignment from the base topographic map contours, strips cross sections at desired station increments and at any other specific points of interest, interactively designs the profile meeting prespecified design data, and directly creates an annotated drawing component. The interactive dynamic profile design process is similar to that of the horizontal alignment process.

With the horizontal alignment and profile at hand, the engineer recalls from a previously defined library of typical roadway sections (templates) the ones applicable to the subject project. Once the templates have been assigned to the desired stations, the final surface contours of the whole design project can be developed, combined (existing and proposed) cross sections can be extracted, and associated material quantities can be computed. The end results are presented in graphic and tabular formats.