RFP Document.pdf

South Dakota Department of Transportation

Request for Proposals Project SD2026-02

Title: Need and Feasibility of Default Traffic Analysis Variables and Statewide Traffic Model for South Dakota

Problem 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; and

2. 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.

Additional Project Information:

Sioux Falls MPO, Rapid City MPO, and Sioux City MPO already maintain established travel demand models. Any statewide assessment must consider these models but will not duplicate or redevelop them.

For this project the following definitions are provided:

• Travel Demand Model is used to predict future travel behavior to guide long-range planning.

• Traffic Forecasting is used to estimate future traffic volumes for design.

This project will consider default traffic analysis variables and parameter behaviors across commonly used SDDOT analysis and modeling tools, including but not limited to:

• Traffic analysis: HCS, Synchro

• Microsimulation: CORSIM, VISSIM

• Travel demand: CUBE, TransCAD

Importance: Understanding the need and feasibility of developing South Dakota‑specific traffic analysis variables and a statewide travel demand model is essential for improving the consistency and reliability of planning, design, operational analyses, and long‑range forecasting across the state. Over‑reliance on non‑representative national default values can result in inconsistent modeling assumptions and increased calibration burden. Likewise, without a statewide travel demand model, SDDOT cannot evaluate systemwide impacts of major corridor investments or understand how changes in one area influence traffic patterns elsewhere. Establishing whether these tools are needed — and feasible — will guide more efficient investments and support better decision‑making across SDDOT.

Research Objectives:

1. Develop an understanding of other state highway agencies using state specific default traffic analysis variables across traffic analysis, microsimulation, and travel-demand modeling.

2. Develop an understanding of other state highway agencies travel demand models and forecasting.

3. Identify the need and feasibility for South Dakota–specific default traffic analysis variables for commonly used traffic analysis, microsimulation, and travel‑demand modeling tools.

4. Identify which defaults traffic analysis variables can rely on national defaults and which require calibration to South Dakota operating conditions.

5. Identify the need and feasibility for statewide traffic model capable of representing existing travel patterns across the state highway system.

6. Develop implementable scenarios that describe potential next steps based on the assessed need, feasibility, and applicability of a statewide travel demand model. Scenarios should describe:

• If the need exists, how SDDOT could implement the next phase (scope, cost ranges, required data, timelines, coordination needs).

• If the need does not exist, what future conditions, data availability changes, or development scenarios might alter that conclusion in the future.

Research Tasks:

1. Meet with the project’s technical panel to review and confirm project scope, schedule, modeling tools used by SDDOT, work plan, available datasets available within SDDOT, and coordination expectations.

2. Conduct a literature review focused on statewide traffic models and on states that have developed state-specific default traffic analysis variables. Include a review of National Cooperative Highway Research Program (NCHRP) reports and syntheses, American Association of State Highway and Transportation Officials (AASHTO) guidelines, FHWA guidelines, crowd-source data usage, use of Big Data sources (such as StreetLight and similar probe-based origin-destination (OD) datasets), traditional and non- traditional methods for traffic demand models, and default traffic analysis variable practices across traffic analysis, microsimulation, and travel-demand modeling.

3. Review SDDOT traffic analysis and modeling workflows across planning, design, operations, and regions. Identify differences in the assumptions, calibration practices, and data use for both traffic analysis and modeling. Prepare a list of interviewees and interview questions for approval by the technical panel, then conduct interviews with SDDOT personnel, MPOs (Sioux Falls, Rapid City, Sioux City), municipalities, and counties with relevant traffic analysis and modeling, and summarize key findings.

4. Interview state highway agencies to document their use or development of state specific traffic analysis variables, statewide travel-demand models and forecasting practices, and lessons learned.

Prepare a list of interviewees and interview questions for approval by the technical panel, then conduct interviews and summarize key findings.

5. Prepare and present for approval by the project technical panel a technical memorandum summarizing findings in Tasks 2 through 4.

6. Assess the readiness, availability, and quality of SDDOT datasets used for traffic analysis. Identify gaps, limitations, and needed remediation steps affecting feasibility.

7. Based on Tasks 2 through 6, identify which default traffic analysis variables can rely on national defaults and which would require South Dakota-specific calibration

8. Conduct a needs and feasibility analysis for developing state specific default traffic analysis variables.

9. Prepare and present for approval by the project technical panel a technical memorandum summarizing findings in Tasks 6 through 8.

10. Assess the readiness, availability, and quality of SDDOT datasets used for traffic modeling. Identify and document gaps and needed remediation steps.

11. Conduct a needs and feasibility analysis for statewide travel-demand models and forecasting and collaboration with the existing MPOs travel demand models.

12. Prepare and present for approval by the project technical panel a technical memorandum summarizing findings in Tasks 10 and 11.

13. Develop implementable scenarios addressing a statewide traffic model, including:

• If the need is YES: Describe how a statewide model could be implemented, including recommended steps, required datasets, integration and collaboration with existing MPO models, estimated costs, staff or consultant needs, and feasible implementation timelines.

• If the need is NO: Identify what future conditions, data availability changes, growth patterns, or planning needs could change the feasibility or create a future need for a statewide model.

14. Prepare and present for approval by the project technical panel a technical memorandum summarizing findings in Task 13.

15. In conformance with the Guidelines for Performing Research for the South Dakota Department of Transportation, prepare a final report and executive summary of the literature review, research methodology, findings, conclusions, recommendations, and implementation strategies.

16. Make an executive presentation of the findings to the SDDOT Research Review Board at the conclusion of the project.

Potential Implementation: If the research determines that South Dakota‑specific default traffic analysis variables and/or a statewide model are needed and feasible, the results will guide SDDOT’s next steps.

Implementation could include a follow‑up project to develop calibrated variables, modifications to SDDOT design and modeling guidelines, coordination with MPO models, and planning for long‑term data collection to support a statewide model. If the research determines the need does not currently exist, SDDOT will still gain clarity on what future conditions could shift that conclusion and what resources would be necessary if a future decision were made to proceed.

SDDOT Involvement: SDDOT will provide access to available data used for traffic analysis, traffic analysis and modeling resources, participate in technical panel meetings, help identify interviewees across the Department, participate in interviews, review technical memoranda, and provide feedback on interim and final deliverables.

Available Funding: $150,000

Duration: 24 months

Anticipated Start Date: October 1, 2026

Terms of Payment: Payment for study services will be made upon SDDOT’s acceptance of key project deliverables. For this study, percentages of total project cost will be paid upon satisfactory completion of the following tasks in Table 1.

Table 1: Payment of deliverables

Task Percentage of Total Cost 5 20% 9 20%

12 15% 14 15%

All Tasks 30% Total 100%

General Information: The South Dakota Department of Transportation solicits proposals from colleges, universities, research institutes, foundations, consultants, federal, state, and local agencies, and others with demonstrated capability and experience in the subject area.

The South Dakota Department of Transportation gives public notice of its policy to uphold and assure full compliance with the non-discrimination requirements of Title VI of the Civil Rights Act of 1964 and related Nondiscrimination authorities. Title VI and related Nondiscrimination authorities stipulate that no person in the United States of America shall on the grounds of race, color, national origin, religion, sex, age, disability, income level or Limited English Proficiency be excluded from the participation in, be denied the benefits of, or be otherwise subjected to discrimination under any program or activity receiving Federal financial assistance. Any person who has questions concerning this policy or wishes to file a discrimination complaint should contact the Department’s Civil Rights Office at 605-773-3540.

Proposals must remain valid for at least 120 days after the submission deadline. All submitted proposals become the property of the South Dakota Department of Transportation. SDDOT has the right to use all information presented in any proposal unless it is specifically annotated as being proprietary. SDDOT considers all information contained in proposals to be privileged and reserves the right to maintain its confidentiality.

All proposals must meet accessibility requirements from Section 508 of the Rehabilitation Act of 1973 and are required to follow Department of Justice guidelines.

South Dakota state statute requires the winning proposal, with proprietary information redacted, to be posted online along with the corresponding contractual agreement.

SDDOT reserves the right to reject any proposals submitted. SDDOT may negotiate with a selected proposer to address specific weaknesses in the selected proposal prior to contract award.

SDDOT is not responsible for any costs, including proposal preparation, incurred by researchers prior to the execution of a contract.

Certification Relating to Prohibited Entity: For contractors, vendors, suppliers, or subcontractors who enter into a contract with the State of South Dakota by submitting a response to this solicitation or https://www.section508.gov/ https://www.ada.gov/resources/2024-03-08-web-rule/ agreeing to contract with the State, the bidder or offeror certifies and agrees that the following information is correct:

The bidder or offeror, in preparing its response or offer or in considering proposals submitted from qualified, potential vendors, suppliers, and subcontractors, or in the solicitation, selection, or commercial treatment of any vendor, supplier, or subcontractor, is not an entity, regardless of its principal place of business, that is ultimately owned or controlled, directly or indirectly, by a foreign national, a foreign parent entity, or foreign government from China, Iran, North Korea, Russia, Cuba, or Venezuela, as defined by South Dakota Executive Order 2023-02. It is understood and agreed that, if this certification is false, such false certification will constitute grounds for the State to reject the bid or response submitted by the bidder or offeror on this project and terminate any contract awarded based on the bid or response. The successful bidder or offeror further agrees to provide immediate written notice to the contracting executive branch agency if during the term of the contract it no longer complies with this certification and agrees such noncompliance may be grounds for contract termination.

Restriction of Boycott of Israel: For contractors, vendors, suppliers, or subcontractors with five (5) or more employees who enter into a contract with the State of South Dakota that involves the expenditure of one hundred thousand dollars ($100,000) or more, by submitting a response to this solicitation or agreeing to contract with the State, the bidder or offeror certifies and agrees that the following information is correct:

The bidder or offeror, in preparing its response or offer or in considering proposals submitted from qualified, potential vendors, suppliers, and subcontractors, or in the solicitation, selection, or commercial treatment of any vendor, supplier, or subcontractor, has not refused to transact business activities, has not terminated business activities, and has not taken other similar actions intended to limit its commercial relations, related to the subject matter of the bid or offer, with a person or entity on the basis of Israeli national origin, or residence or incorporation in Israel or its territories, with the specific intent to accomplish a boycott or divestment of Israel in a discriminatory manner. It is understood and agreed that, if this certification is false, such false certification will constitute grounds for the State to reject the bid or response submitted by the bidder or offeror on this project and terminate any contract awarded based on the bid or response. The successful bidder or offeror further agrees to provide immediate written notice to the contracting executive branch agency if during the term of the contract it no longer complies with this certification and agrees such noncompliance may be grounds for contract termination.

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.

mailto:andy.vandel@state.sd.us mailto:danny.doorn@state.sd.us mailto:margo.mcdowell@state.sd.us