Variable Message Signs (VMSs) are widely used to advise motorists of roadway conditions and incidents so that appropriate actions can be taken by the driver to enhance the safety and efficiency of transportation operations. VMSs are often supplemented by Highway Advisory Radios (HARs) in urban and recreational areas to provide a comprehensive Advanced Traveler Information Systems (ATIS). While extensive work had been done studying the use of the VMS technology for incident scenarios, little or no known work had been done to define practices and policies for use of VMS and HAR during non-incident conditions.
Variable message signs are often used in both urban and rural applications to provide information to motorists related to incidents. An incident is any non-recurring event that causes a reduction in roadway capacity or an abnormal increase in demand. Some examples of incidents include traffic collisions, disabled vehicles, spilled cargo, highway maintenance and construction projects, weather-related concerns, and special events attracting large numbers of vehicles. Significant research has been done in the art of displaying and formatting messages for incident applications; these messages typically include a location and problem description in the message.
Many state transportation departments and other local and municipal agencies have been at the forefront of ATIS implementation, providing motorist information in order to create a more efficient and safer transportation system. Numerous agencies also maintain a large number of urban and rural permanent VMSs, as well as a number of HAR transmitters, during construction and incident-related conditions. However, many agencies, such as the Arizona DOT, only made limited use of their ATIS infrastructure for non-incident-related conditions. Because there were no official documents and information related to the non-incident use of VMS and HAR, this research provided guidance to the ENTERPRISE members in developing policies for non-incident use of VMS and HAR.
The work completed as a part of this project included the following:
Task 1: Literature Search
A thorough literature research was conducted to identify pertinent documents related to non-incident usage of VMS and HAR.
Task 2: VMS and HAR User Surveys
This task identified and made telephone contacts with VMS and HAR users at all 50 State transportation departments to learn what each department’s current polices and practices were related to non-incident usage of VMS and HAR. Some examples of questions that practitioners were asked include:
- How many VMSs or HARs are you responsible for?
- Do you use your VMSs and HARs during non-incident conditions?
- What types of non-incident information do you display on your VMSs?
- How are your HARs used during non-incident conditions?
- Do you have warrants for each type of message you disseminate?
- Do you have examples of formats of the common messages used during non-incident conditions?
- Can you identify any difficulties with VMS or HAR usage during nonincident conditions?
- What is the public perception of the ATIS program, which you operate?
It was anticipated that more detailed follow-up questions would be asked of those practitioners who make frequent use of non-incident-related messages for their ATIS operations.
Task 3: Draft Report
A concise draft report was developed to document the results of the literature search, and practitioners’ interviews. The report contained summaries of the responses received in tabular and graphical formats. A main focus area of the report was recommendations for non-incident use of the VMS and HAR ATIS technology. The consultant also endeavored to qualitatively identify the benefits of non-incident use of the technology. The report included an Executive Summary of key findings.
Task 4: Final Report
Following review by ENTERPRISE and other interested parties, the project consultant incorporated comments and prepare a final report. The report was presented both electronically and in hard copy formats. The consultant developed a PowerPoint presentation of the project findings for public presentation.
- The following products were delivered from this project:
- A Final Report that can be used by ATIS operators to develop policies and procedures for non-incident use of VMS and HAR.
- A public presentation of the report’s findings to an appropriate national technical audience, as recommended by the ENTERPRISE group.