What is meant by final design?  When does preliminary design end and final design recognized?  The term can be interpreted loosely, but the two stages of design clearly distinguish themselves when you begin preparing contract documents.

Title 23, CFR, Section 636.103 (23 CFR §636.103), defines the terms “Preliminary Design” and “Final Design” as follows:

(1) “Final design means any design activities following preliminary design and expressly includes the preparation of final construction plans and detailed specifications for the performance of construction work.”

(2) “Preliminary design defines the general project location and design concepts. It includes, but is not limited to, preliminary engineering and other activities and analyses, such as environmental assessments, topographic surveys, metes and bounds surveys, geotechnical investigations, hydrologic analysis, hydraulic analysis, utility engineering, traffic studies, financial plans, revenue estimates, hazardous materials assessments, general estimates of the types and quantities of materials, and other work needed to establish parameters for the final design. Prior to completion of the NEPA review process, any such preliminary engineering and other activities and analyses must not materially affect the objective consideration of alternatives in the NEPA review process.”

Another great resource that helps explain final design is an article posted at FHWA’s Every Day Counts site.

If you’re still unclear about what is meant by final design, don’t hesitate to contact your Local Assistance Engineer.

Updated August 8, 2012