National ITS Architecture Documentation
The architecture documents make up a comprehensive and critical resource listing the different components of ITS and the many connections that unite them into an overall framework for deployment. These documents offer thousands of pages of information to help in designing intelligent transportation systems.
The entire suite of core architecture documents was published in June 1996 with the exception of the Market Packages (now called Service Packages) document, which was published in December 1999 for Version 3.0 and Security Document which was published in October 2003 for Version 5.0. The Regional ITS Architecture Guidance Document, originally published in October 2001, was updated on July 2006 and added to the Architecture documentation suite. The System Engineering for Intelligent Transportation Systems Document, originally published in January, 2007, has also been added to the Architecture documentation suite.
Version 7.0 of the National ITS Architecture is the direct result of inputs from the ITS community. Changes were incorporated into the logical architecture, physical architecture, and several other key architecture definition documents for this version. Documents that provide performance, cost, and benefits assessments were not updated. The revision dates next to the document titles indicate which documents were updated for Version 7.0 (January 2012).
The National ITS Architecture document set is listed below and is available as compressed PDF files, which may be downloaded and viewed using Acrobat Reader.
National ITS Architecture Documents:
The architecture documents fall into the following categories:
User Services
This one Document consolidates the descriptions of all 33 current user services into a single document. If additional ITS user services are defined in the future, this document will be updated to include them.
The User Services (January 2005 release) document provides an overview of current ITS User Services.
Executive Summary
The Executive Summary (January 2012 update) is a single document that provides an overview of the most important aspects of the National Architecture, most notably the Logical and Physical Architectures.
Architecture Definition
There are six documents that provide architecture definition:
The Vision Statement (January 2012 update) sketches a number of possible scenarios of ITS development over the next 20 years.
The Mission Definition (May 2007 update) is one of the original National ITS Architecture documents and was developed to explain the original mission of the architecture development effort. It also contains an operational concept for the original architecture development effort tied to the original categorization of urban, interurban, and rural needs. The third major section of the document is a set of operational requirements that define a functional, performance, and data requirements for systems that provide the functionality described in the architecture. While the document has been updated over the years to include the revisions to user services and service packages in the architecture, it basically represents a description of the original architecture development effort, and as such will not be further updated, but retained as an expression of the original mission, needs, and requirements that drove the original development of the National ITS Architecture.
The Logical Architecture (January 2012 update) document is made up of three volumes:
- Description (Volume 1)
- Process Specifications (Volume 2)
- Data Dictionary (Volume 3)
The Physical Architecture (January 2012 update) document describes the transportation and communications layers resulting from the partitioning of the processes within the logical architecture, presents architecture flow diagrams that show data passing among physical subsystems, and provides characteristics and constraints on the data flows.
The Service Packages (previously called Market Packages) (January 2012 update) document expands upon the Service Package discussion in the Implementation Strategy by providing a comprehensive review of each of the Service Packages describing how Service Packages can be used to plan and implement integrated transportation systems customized to local needs.
The Theory of Operations (January 2012 update) document provides a detailed narrative of the manner in which the architecture supports the ITS user services, described in the Mission Definition document.
Evaluation
There are six documents that pertain to architecture evaluation:
The Communications Document (January 1997 update) provides a thorough analysis of the communications requirements of the National Architecture, and ITS in general, and includes a discussion of options for implementing various communications links.
The Evaluatory Design (June 1996 release) document is intended to evaluate the National Architecture 's performance, benefits, and costs for three conceptual scenarios at various points in time. The scenarios consist of "typical" deployment environments: urban, inter-urban, and rural.
The Cost Analysis (June 1996 release) document has two purposes. First, it develops a high level cost estimate of the expenditures that are associated with implementing ITS components. Second, it is a costing tool for implementers, by providing unit prices and systems costs of ITS subsystems.
The Performance and Benefits Study (June 1996 release) assesses the technical performance of the National Architecture on a number of system-level and operational-level criteria.
The Risk Analysis (June 1996 release) document presents an analysis of potential critical risks that may delay or prevent the deployment of ITS technologies, and recommends mitigation plans which will eliminate of reduce these risks to the deployment process.
The Evaluation Results (June 1996 release) document contains a concise summary of the various evaluations that were performed in five other National Architecture documents: Evaluatory Design, Communications Analysis, Cost Analysis, Performance and Benefits, and Risk Analysis.
Implementation Strategy
There is one document that pertains to architecture implementation strategy:
The Implementation Strategy (September 1998 update) document presents a process for implementing ITS services in a phased approach. The process is part of an overall strategy that includes recommendations for future research and development, operational tests, standards activities, and training.
Standards
There is one document that addresses ITS standards development and the relationship of ITS standards to the National ITS Architecture. It was created as a guide for standards developers during the initial stages of the ITS standards program, and has led to many new ITS standards since then (See www.standards.its.dot.gov for more information on ITS Standards). As a result of enhancements to the National ITS Architecture since this document was published, there are now additional candidate architecture flows to be considered for future standardization. Please consult the Standards section of the National ITS Architecture website for the most recent standardization opportunities.
The Standards Development Plan (June 1996 release) discusses the issues that were involved in the development of system interface standards.
Security
There is one document that addresses security for the National ITS Architecture:
The Security (January 2012 update) document discusses how security is reflected in the National ITS Architecture both in ITS functionality and securing ITS.
Regional ITS Architecture Guidance (Version 2.0)
The Regional ITS Architecture Guidance: Developing, Using and Maintaining an ITS Architecture For Your Region (Version 2.0) (July 2006 update) is a guide for transportation professionals who are involved in the development, use, or maintenance of regional ITS architectures. The document describes a process for creating a regional ITS architecture with supporting examples of each architecture product. It describes a process for creating a regional ITS architecture with supporting examples of each product and discusses mainstreaming ITS into the planning and project development processes. This update expands upon the topics of Using and Maintaining a regional ITS architecture.
Systems Engineering for Intelligent Transportation Systems
The Systems Engineering for Intelligent Transportation Systems (January 2007 release) handbook provides a good introduction to systems engineering and a basic understanding of how it can be applied to planning, designing, and implementing intelligent transportation systems (ITS) projects. It walks step by step through the project life cycle and describes the systems engineering approach at each step. It describes how to begin implementing the systems engineering approach on ITS projects and incorporate systems engineering more broadly into your organization's business processes and practices.
