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21st Century Operations Using 21st Century Technologies

Model Systems Engineering Documents for Central Traffic Signal Systems

Executive Summary

This guidance document for procuring Central Traffic Signal Systems (CTSS) is part of a series of Model Systems Engineering Documents. This guidance document incorporates the Model Systems Engineering Documents for Adaptive Signal Control Technology (ASCT) Systems, published in 2012 by the Federal Highway Administration (FHWA). Over 100 adaptive systems have been implemented in the United States since 2010, a significant number of these procurements have utilized the model systems engineering document process.

This guidance expands the scope to cover central traffic signal systems and performance management technologies. This framework will support the alignment of an agency's over- arching objectives with their system operations strategies to guide the procurement of a system that best suits their needs within stated constraints. It will reduce the level of unmet expectations by stakeholders, improve the confidence of vendors that they will be able to verify compliance with stated requirements, and reduce the incidence of biased specifications.

The model systems engineering documents provide a framework for agencies to clearly articulate their needs, and specify succinct and comprehensive system requirements to guide the procurement and implementation of Intelligent Transportation Systems (ITS). Target procurements include those projects that:

  • Cannot reasonably afford development of systems engineering documents from scratch.
  • Make selections from existing device and software products in the market, rather than supporting new product or software development.

These model documents make it possible for agencies to develop meaningful systems engineering documents that will effectively support procurements and reduce risk for smaller, more routine ITS implementation projects.

Using these documents will support an agency's compliance with 23CFR940.11.

Part of an ITS Implementation Process

A CTSS implementation project will be part of an overall ITS implementation strategy to support the agency's operations planning. The user will be able to identify the goals, objectives and activities from those planning efforts to select the appropriate needs within the Model Concept of Operations.

During the project phase, this Concept of Operations will support documentation of system requirements to a level of detail necessary for clarity during a CTSS procurement. Verification and Validation will confirm that the system fulfills the requirements and successfully meets the agency's needs. Demonstrably meeting needs ensures that the agency will attain the operations objectives driving the project.

What the User Will Do

The user will review sample statements that reflect each of the agency's needs related to their operations objectives. Following this guidance, the user will tailor these sample statements to address specific situations. Selecting and tailoring user needs in the Concept of Operations will link to a set of clear and concise requirements. This guidance leads the user to develop the following systems engineering documents:

  • Concept of Operation.
  • System Requirements.
  • Verification Plan.
  • Validation Plan.

Procurement Support

Central traffic signal systems procured using traditional low-bid processes impose an unnecessary risk on project success. A number of studies and experience has demonstrated that Intelligent Transportation Systems, including CTSS are complex and require sufficient integration and customization that are difficult to anticipate and manage effectively within a low-bid process. This guidance includes a discussion of procurement processes that make effective use of systems engineering documents to minimize project risk and comply with Federal procurement regulations.

When Federal funds are involved in a project, the systems engineering documents are subject to review by the appropriate FHWA Division Office, and must follow State procedures as determined between the FHWA Division Office and the State transportation agency.

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