Guidelines On The Selection And Design Of Messages For Changeable Message Signs

Guidelines on the Use and Operation of Changeable Message Signs

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

Changeable Message Sign Displays During Non-incident, Non-roadwork Periods

Policies for Use of Changeable Message Signs in Highway Work Zones

Portable Changeable Message Sign (PCMS) systems used in work zones are programmable supplementary traffic control devices that display messages composed of letters, symbols or both and provide information and instructions to the traveling public approaching work zone activities. The study seeks to develop warrants and criteria for PCMS deployment in Illinois highway work zones. It is recommended that PCMS systems be used during long- and intermediate-term stationary work, for traffic control through incident areas, and in projects where advance-time notification is needed. The discussion focuses on spacing criteria, number of signs required, sign visibility and message legibility, text alignment, distance criteria, message length, duration and type, project-level operational guidelines, message storage and dissemination, repair, maintenance and utility costs, as well as control and coordination issues. The study concludes that additional research is needed in order to: develop a comprehensive standardized statewide database of messages and message abbreviations; develop a comprehensive repository with information about the technology of the various components of the PCMS units; coordinate PCMS units used in highway work zones with a corridor or regional ATMS system; and maintain information about the use of a PCMS unit in a work zone project and possibly integrate it with other relevant information in a management system.