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7 3-D CADD model into a photograph. Today's transportation · Improved conformance with the ISO 9000 or Occupa- planner has an extensive portfolio of affordable hardware and tional Health and Safety Administration regulations software applications to use for computerized visualization. through better document control procedures; · Fewer lost, damaged, and misfiled documents; · Immediate availability of accurate information; WHY THE NEED FOR VISUALIZATION? · Streamlining of the change process; · Improvement in time to market; and The need for visualization within the transportation commu- · Improved quality. nity can be traced back to two factors: (1) improvement to the design process and (2) public and stakeholder involvement. The success of 2-D CADD has led developers to improve Both of these issues have driven the advancement and use of CADD capabilities by incorporating 3-D tools within the soft- the technology. ware. Three-dimensional design was the next evolution of the CADD process. By initially generating the design in 3-D, the Improvement to Design Process process of design can be improved, achieving better quality control, improved process flow, and a natural extension to CADD technology was initially devised to improve the developing visuals from the design. If the project is initially drafting process by automating mundane routines such as designed in 3-D, then creating renderings, animation, or sim- border creation and text input. Vendors strived to improve ulation will be a logical progression rather than an add-on the process so that higher-quality work could be produced application. Incorporating 3-D into the design process will with less labor. In the mid-1980s, costbenefit analyses were lead to increased demand in the use of visualization tools. conducted to justify the up-front expense of hardware and These visual tools translate into a variety of potential cost sav- software needed to implement CADD. The investment for ings, including the following: mainframe computers, workstations, and software utilities regularly exceeded $100,000 (5). To justify these expenses, · Increased quality control, which leads to fewer con- analyses were conducted that measured and compared the struction changes and improved production schedules. performance of design production on a drafting table with · Better and more cost-effective design. Because visual the performance of a CADD system. The testing proved that tools help to understand the design alternatives more using CADD, even with the sizable up-front costs, was war- effectively, better design decisions can be made. ranted. Two-dimensional CADD (see Figure 4) greatly · Increased communication and understanding. It is far improved the drafting and design process. Benefits included easier to convey design ideas or options with visuals. the following: The old adage "A picture is worth a thousand words" holds true with visualization. · Elimination of the need for tedious redraw (CADD · Improved timetables for approvals. When the under- could be used for productive design and analysis standing of a project is improved, acceptance by stake- functions); holders or the public can be obtained more efficiently. Garnering rapid approvals or reducing approval times can · A common electronic database; be invaluable to costs savings on transportation design · Reduced retrieval and print times for documents projects. through a document management solution; · Improved information flow with workflow and e-mail tools; Public and Stakeholder Involvement Public and stakeholder involvement is seen as a major rea- son for the need for visualization tools. The general public, resource agencies, and other stakeholders are continually exposed to 3-D computerized renderings and animation. Computerized visuals are used in the daily activities of most people, from the entertainment community (in which visualization is used for television commercials, print advertisement, movies, and much more) to industrial uses such as computer numerical control (6) machining and geo- graphic information system (GIS) applications. Computer- ized visuals dominate the public eye today. With this mind- set, the public expects and demands to see similar visuals at public presentations. This pressure has driven transporta- tion agencies to develop and implement visual tools for FIGURE 4 2-D CADD roadway alternative plan. public outreach.