Evaluating Alternative Operations Strategies to Improve Travel Time Reliability

Evaluating Alternative Operations Strategies to Improve Travel Time Reliability

Author: National Academies of Sciences, Engineering, and Medicine (U.S.)

Publisher: Transportation Research Board

Published: 2022-03-29

Total Pages: 378

ISBN-13: 0309273706

DOWNLOAD EBOOK

This report from the second Strategic Highway Research Program (SHRP 2), which is administered by the Transportation Research Board of the National Academies, sets out requirements for travel time reliability within a performance-based planning process. The research includes an effort to determine the economic value of improvements in travel time reliability by applying options theory from the financial sector. The report includes two succinct tables that describe requirements for person and freight trips for reliable transport, as well as a forecast of the year 2030 under alternative assumptions that may influence travel time reliability.


Advanced Notification Messages and Use of Sequential Portable Changeable Message Signs in Work Zones

Advanced Notification Messages and Use of Sequential Portable Changeable Message Signs in Work Zones

Author:

Publisher:

Published: 2005

Total Pages: 90

ISBN-13:

DOWNLOAD EBOOK

In this report, researchers document the results of a laptop-based human factors study of alternative formats of presenting advance notice work zone information on portable changeable message signs (PCMSs) and a Texas Transportation Institute (TII) driving simulator study of the ability of motorists to capture and process information on two PCMSs used in sequence to convey information about upcoming traffic situations. Based on the studies, researchers recommend that messages that require the display of calendar dates for future roadwork and other traffic control activities should utilize a message format consisting of the three-character abbreviation of the month (e.g., APR for April) in conjunction with the date. When future work activities span several days all in the same month, the month needs be noted only once in the message (i.e., APR 21-23) rather than repeating the month (i.e., APR 21-APR 23). The ITI driver simulator study results indicate the need to keep overall messages at or below the four-unit maximum recommended in existing guidelines. Researchers found that presenting five units of information on sequential PCMSs resulted in low comprehension rates, below what would be acceptable for highway applications. However, by keeping the message length to four units, it does appear that the use of sequential PCMSs will result in comprehension rates comparable to those obtained by presenting the same information at a single location on a large dynamic message sign (DMS), and is recommended as an acceptable formatting approach for TxDOT. Comprehension may be enhanced by repeating one of the units of information on both PCMSs.


Dynamic Message Sign Message Design and Display Manual

Dynamic Message Sign Message Design and Display Manual

Author: Conrad L. Dudek

Publisher:

Published: 2004

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

This Dynamic Message Sign Message Design and Display Manual was written for use by Texas Department of Transportation (TxDOT) personnel who have responsibility for the operation of and/or message design for large permanent dynamic message signs (DMSs) or portable DMSs. The Manual is designed to help both new and experienced users of DMSs at various levels of the agency including 1) entry-level personnel, 2) personnel very experienced with traffic operations, and 3) managers. It provides very specific information for entry-level personnel, reminders for experienced personnel, and higher-level information for managers regardless of whether they work in one of the Traffic Management Centers (TMCs) in the state.


Development of Manuals for the Effective Use of Variable Message Signs. Final Report

Development of Manuals for the Effective Use of Variable Message Signs. Final Report

Author: John S. Miller

Publisher:

Published: 1995

Total Pages: 48

ISBN-13:

DOWNLOAD EBOOK

A comprehensive research effort to develop operator's manuals for variable message signs (VMSs) was undertaken to improve the operations of both portable and permanent (fixed-site) VMSs in Virginia. This report describes the development of two manuals, the Permanent VMS Operator's Manual and the Portable VMS Operator's Manual which will be published separately. These manuals were based on information obtained from the literature, VMS operators, and motorists. Issues addressed by the manuals include when a VMS should be used, where a portable VMS should be placed, and the design of the VMS message. The manuals are not simply a list of pre-defined messages. They are a series of concise modules guiding the operator through the thought process required to use a VMS effectively. The operator follows a logical decision tree from module to module, to achieve the best placement and best message for a VMS. Effective VMS use actually requires a complex thought process, despite the apparent simplicity of the messages. The manuals include essential material about VMS operation. Based on theoretical calculations and motorists' experiences, it is strongly recommended that a VMS use no more than two message screens. A single message screen is preferred. VMSs should be used only to advise drivers of changed traffic conditions and convey specific traffic information concisely. Due to limited information capabilities, VMSs should be used in conjunction with other means of communication such as highway advisory radio and static signs. Most importantly, it is crucial that credibility be maintained. Incorrect information can have extreme consequences in terms of VMS effectiveness.


Guidelines on the Use and Operation of Changeable Message Signs

Guidelines on the Use and Operation of Changeable Message Signs

Author: Conrad L. Dudek

Publisher:

Published: 1992

Total Pages: 120

ISBN-13:

DOWNLOAD EBOOK

This report is intended to be a primer on the characteristics that affect the design, use and operations of changeable message signs (CMSs), and to provide guidance on the selection of the appropriate type of CMS display. Guidelines on the selection and design of CMS messages are presented in a companion report, Report No. FHWA/TX-92/1232-10 entitled "Guidelines on the Selection and Design of Messages for Changeable Message Signs". This report is an update and consolidation of the following reports: (1) C.L. Dudek and R.D. Huchingson, "Manual on Real-Time Motorist Information Displays", FHWA-IP-86-16, August 1986; (2) C.L. Dudek, "Guidelines on the Use of Changeable Message Signs", FHWA-TS-90-043, May 1991; and (3) C.L. Dudek, "Portable Changeable Message Signs at Work Zones", FHWA/TX-85/07+292-4, July 1984