This journal is disseminated under the sponsorship of the US Department of Transportation in the interest of information exchange. The US Government assumes no liability for its content or use thereof. The US Government does not endorse products or manufacturers. Trade or manufacturers' names appear herein solely because they are considered essential to the objective of this publication.

The Volpe Journal is published twice annually by the Volpe National Transportation Systems Center, 55 Broadway, Cambridge, Massachusetts, 02142-1093, and is distributed free of charge. To be placed on the mailing list, contact Lynn C. Murray at 617/494-2224 or send e-mail to: lynn.murray@dot.gov.

Volpe Center Technical Contributors

Volpe Participation in Cooperative Threat Reduction
Ross T. Gill
James H. Lamond

Global Positioning System
Karen L. Van Dyke
Maurice J. Moroney Jr.

Transportation Learning
Dr. Peter A. Manning

Rodney E. Slater, Secretary
US Department of Transportation

Kelley S. Coyner, Administrator
US DOT Research and Special Programs Administration

Dr. Richard R. John, Director
Volpe National Transportation Systems Center

Editor
Lynn C. Murray, Chief Communications and Technology Outreach, Volpe Center

Prepared by
Planners Collaborative, Inc.

Publication Director
Ed Shoucair

Managing Editor
Sian E. Steward

Senior Editor
Jennifer Shearman

Lead Writers
Jeff Collins
Dr. Peter A. Manning
Jennifer Shearman

Contributing Writers
Susan Dresley
Mona Hochberg
Lynn C. Murray
Tim Reardon
Andrew Semble

Graphic Design
Dartanyan Danier
Naoki Nitta
Norris Padmore
Brad Schneider

Production
Robert B. Park

Photography
Jennifer Masho
Aldo A. Formiconi

Additional photographs obtained from:
Ross T. Gill
James H. Lamond
AP/World Wide Photos
Architect of the Capitol
Smithsonian Institution

The Volpe Journal is also available on the Volpe Center Web site at www.volpe.dot.gov.

ISSN 1526-5188