Producing a design product in the form of a concept, alternate, or layout if done correctly should be a creative process. The layout should paint a picture of what is in place, what is planned, what is affected, and how the decisions were made. Good layout development involves research, development of alternatives, gathering public and peer input, analysis of and refining alternatives, polishing into a final product, and updating as the project requires.
A maximum amount of research focused on the project's area should be pursued as prescribed in the Layout Content Review Checklist. This research should include and not be limited to the following types of information gathering:
- Previous final plans will help tell the story of the in place roadway
- Site plans can assist in indicating future development in the area
- A field trip to the site can help confirm or add to base map data
- A contour map does well to depict the area's landform and give design guidance
At this stage in the project development process, it is satisfactory to include information in the base map and layout content that is approximate as long as proper notation as such is included so that Final Design and Right-of-Way knows that this information should be confirmed.
Keeping creative should be an ongoing process and layout development should occur through the iterative process of developing alternatives and gathering input. The development of alternatives can not be stressed enough as talk is good, but a picture is worth a thousand words. Some of the unusual and seemingly poor choices sometimes are best drawn to exhibit their value. Evaluation of these alternatives is best done by a large group of personnel representing a diverse background. As such, networking you're your design forces is important in providing the best design solution. Peer review is an ideal way to accomplish quality assurance and pays dividends while also sharing ideas and experiences. As emphasized by AASHTO, multi-disciplinary design efforts must remain operative until the final plans are developed and the design process is should be an evolution. Layout changes are just part of the design efforts which could be considered questionable if a number of alternates are not studied prior to the final layout.
The layout process may appear formal, however, it is important to stay creative not only in content as described previously, but also in appearance and drafting. Like any creative process, all layouts need not take on a standard appearance, but only present similar content to the audience. The final layout should take on a more polished appearance as it is viewed and evaluated not just by the highway community, but by the general public and their elected representatives who may be unfamiliar with plans and technical drawings. This is why the layout appears the way it does as it is a unique story that represents proposed designs using special colors, notes, dimensions, labels, arrows, traffic volume tables, legends, and insets. The layout work often becomes a sales tool for the Project Manager to show acceptable design and related impacts. The Final Layout is retained as part of the project record and is a useful picture for use before, during, and after construction.
A question often asked is: "When is a layout completed?" Officially, it might be argued that work ends once the layout is staff approved and the Final Layout is distributed which allows Final Design to begin. In reality, designs sometimes need to be altered during Final Design as more detailed information is gathered. Depending on the project, the Project Manager may desire to keep a layout current or updated as changes to the design and topography occur. This may be particular important when the timeline of a project is extended over a great deal of time and MnDOT personnel and local representative changes are likely to occur during the project development process. When layout work is ended in essence has to be evaluated on a case by case basis as determined by local needs.
- Layout Content Review Checklist (Excel 78KB)
- Road Design Manual
- HPDP Geometric Design Resources
- Consultant Pre-qualification
- Construction Project Log
- Trunk Highway Logpoints
- Minnesota Roundabouts