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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Public Roads - May/June 2005

May/June 2005
Issue No:
Vol. 68 No. 6
Publication Number:
Table of Contents

Communication Product Updates

Communication Product Updates

by Zac Ellis of FHWA's Office of Research and Technology Services

Below are brief descriptions of products recently published online by the Federal Highway Administration's (FHWA) Office of Research, Development, and Technology. Some of the publications also may be available from the National Technical Information Service (NTIS). In some cases, limited copies are available from the Research and Technology (R&T) Product Distribution Center.

When ordering from NTIS, include the NTIS publication number (PB number) and the publication title. You also may visit the NTIS Web site at to order publications online. Call NTIS for current prices. For customers outside the United States, Canada, and Mexico, the cost is usually double the listed price. Address requests to:

National Technical Information Service

5285 Port Royal Road

Springfield, VA 22161

Telephone: 703–605–6000

Toll-free number: 800–553–NTIS (6847)

Address requests for items available from the R&T Product Distribution Center to:

R&T Product Distribution Center, HRTS-03

Federal Highway Administration

9701 Philadelphia Court, Unit Q

Lanham, MD 20706

Telephone: 301–577–0818

Fax: 301–577–1421

For more information on research and technology publications from FHWA, visit the Turner-Fairbank Highway Research Center's (TFHRC) Web site at, FHWA's Web site at, the National Transportation Library's Web site at, or the OneDOT information network at

Software Reliability: A Federal Highway Administration Preliminary Handbook

Publication No. FHWA-HRT-04-080

The objective of this handbook is to provide reference assistance to highway engineers, software developers, and project managers involved in verifying, validating, and producing reliable software products. Specifically, the handbook demonstrates the need for verification and validation of highway-related software, introduces important concepts, and defines problems specific to highway-related software. The handbook also provides information on several new techniques that address the special needs of software pertaining to highways:

  • Wrapping, the use of embedded code to make a program self-verifying
  • SpecChekª, a verification and validation tool to check software with its specifications
  • Real-time computation of round-off errors and other numerical errors
  • Phased introduction of new software to minimize failures

In addition, the handbook helps engineers, software developers, and project managers integrate verification and validation processes into the development of new software and the retrofitting of existing products.

Evaluation of Procedures for Quality Assurance Specifications

Publication No. FHWA-HRT-04-046

This technical report summarizes the steps taken to create Optimal Procedures for Quality Assurance Specifications (FHWA-RD-02-095), which is a comprehensive quality assurance (QA) manual supported by scientific evidence and statistical theory that provides step-by-step procedures and instructions for developing effective and efficient QA specifications. The report features the analyses conducted to support the QA recommendations made in the final manual. Researchers used both analytical and computer simulation approaches to assess the effectiveness of various QA techniques, and the method of analysis used depended on the type of decision that needed to be made.

The researchers selected percent within limits (PWL), or its complement, percent defective (PD), as the best measure of quality because it combines both the sample mean and standard deviation into a single measure of quality. Since such an approach is based on a single, composite quality measure derived from a general performance model, it can predict expected pavement life and can help determine payment factors even when multiple quality characteristics must be measured. The report also provides a detailed discussion and analysis of the risks involved in the various approaches to verifying a contractor's test results, highlighting the relatively high risks associated with typical agency verification testing frequencies.

Traffic Analysis Toolbox, Volume I: Traffic Analysis Tools Primer

Publication No. FHWA-HRT-04-038

This publication provides an overview of the traffic analysis tools used in the transportation analysis process. The primer defines the different categories of tools and presents the challenges and limitations of each. In addition, the document compares analyses using the Highway Capacity Manual (HCM) and those based on traffic simulations, including criteria for selecting the most appropriate type of traffic analysis tool. An appendix provides a list of the tools within each category and their corresponding Web sites.

This is the first in a series of volumes in the Traffic Analysis Toolbox. The other volumes are Volume II: Decision Support Methodology for Selecting Traffic Analysis Tools (FHWA-HRT-04-039) and Volume III: Guidelines for Applying Traffic Microsimulation Modeling Software (FHWA-HRT-04-040).