Need & Feasibility of Default Traffic Analysis Variables/Traffic Model

Title: Need and Feasibility of Default Traffic Analysis Variables and Statewide Traffic Model for South DakotaProblem Description: The South Dakota Department of Transportation (SDDOT) does not currently have validated, South Dakota specific default traffic analysis variables for key parameters used in traffic analysis, microsimulation, and travel demand modeling tools. Analyst often rely on national or software-provided default traffic analysis variables that do not accurately reflect South Dakota conditions, including differences between rural and urban environments, unique travel patterns, and local driver and vehicle behavior. This leads to inconsistent modeling practices, increased calibration burdens, and reduced confidence in project-level and system-level decisions. Federal Highway Administration (FHWA) has previously raised concerns over-reliance on unvalidated defaults in SDDOT studies.Although national research exists such as NCHRP Report 599 South Dakota has not conducted a statewide effort to validate default parameters in 20 years. Without modern, state-specific default traffic analysis variables, SDDOT cannot ensure consistent analyses across corridor studies, project development, operations, and regional planning.Additionally, SDDOT does not have a statewide travel demand model (TMD) that can represent existing travel patterns or evaluate system-level impacts of major network, corridor, or freight changes. However, SDDOT has not yet determined whether such a model is needed, feasible, applicable, or cost-effective. A statewide model would require substantial data inputs, coordination with Metropolitan Planning Organizations (MPOs), and ongoing maintenance, and these factors must be assessed before moving forward.To support consistent planning, design, and operational decisions, SDDOT needs a structured needs and feasibility assessment to determine:1. Whether South- Dakota specific traffic analysis variables are needed and feasible; and2. Whether a statewide travel demand model is needed, feasible, applicable, and beneficial relative to cost and data requirements.This research will provide the foundation for future decisions by identifying needs, feasibility factors, benefit-cost considerations, and practical implementation scenarios.Proposal Deadline: Proposals are due to the SDDOT by 5:00 pm CDT on Friday, June 12, 2026. This deadline is firm. Extensions will not be granted.Proposals must be submitted as an e-mail attachment in Portable Document Format (PDF) not exceeding 14MB. The email must be addressed to andy.vandel@state.sd.us and danny.doorn@state.sd.us. Proposers should send the e-mail using Delivery Receipt and Read Receipt options to verify successful delivery.Proposal Guidelines: Proposals must fulfill the requirements listed in the document entitled RESEARCH PROPOSAL PREPARATION, SUBMISSION, AND EVALUATION and dated April 27, 2026.Proposal Evaluation: Proposals will be evaluated by a technical panel knowledgeable in the problem area. Selection will be made in consideration of criteria listed in RESEARCH PROPOSAL PREPARATION, SUBMISSION, AND EVALUATION.Project Management: Danny Doorn is responsible for the management of this project and can be reached at danny.doorn@state.sd.us to answer inquiries.