TO:TRANSPORTATION PROFESSIONALS, MANAGERS, & POLICY MAKERS
FROM:ARIZONA TRANSPORTATION INSTITUTE
The volume of information on transportation issues, policies, technologies, and related topics is huge. Not even the most well-read professional can keep up with everything that might be useful to know. The Transportation Research Digest series is designed to expedite the transmission of information by condensing and summarizing significant documents. Busy professionals or managers may quickly obtain the gist of new developments and determine whether they need to see the full document.
The Transportation Research Digest is not meant to present definitive resolutions of scientific or policy controversies, but contributions to the pursuit of knowledge and the debate of issues. The intent is to be comprehensive rather than conclusive on the multitude of issues and topics of concern to those working in the field of transportation. Readers are encouraged to obtain the original document summarized in the Transportation Research Digest and subject the content to their own judgment.
Transportation professionals who would like to recommend documents to be summarized or submit summaries to be considered for inclusion in this publication are invited to do so. To recommend a document please send a copy (or information indicating how a copy can be obtained) of the research report to be summarized. To be considered, the report must meet the following requirements: (1) it is transportation related, (2) it is no more than two years old, (3) there is enough information in the report to warrant a two page summary. To write a summary, insure that the document being summarized meets the above requirements. The summary should be submitted in an electronic format. This summary should be in the 500 to 800 word range and may include tables and/or simple graphics—all of which must fit within the Transportation Research Digest’s two-page format. Submissions are subject to editing for clarity and length. We do not guarantee that all submissions will be published.
If you would like to obtain the full report upon which a Transportation Research Digest summary is based you have several options. Check your local university library. You may want to contact the publisher using the contact information appearing in the Transportation Research Digest. Some of the documents are free for the asking. Others can be purchased.
There is a database listing of all the previously published Transportation Research Digests that we have on file (back to 1984). Copies of the list or of portions of the list selected by topic or mode can be provided on request. You may also access the database via the internet at
Transportation Research Digests from December 1995 to November 2003 are available at
A “Topic” code in the Table of Contents will help readers more quickly identify items of interest. The topic codes are explained in the table below.