Effective traffic management for unplanned incidents requires tools and resources that can be deployed rapidly to respond to unpredictable conditions and circumstances. For work zones, closures or restrictions, special events, and other planned activities, agencies will typically develop a strategic traffic control or management plan. A key tool in helping to execute the plan would likely be fixed or portable VMS with vital instructions or information about immediate hazards and conditions.
Incident conditions that require rapid deployment of portable or truck mounted VMS often require very specialized, incident-specific information that might not be found in pre-planned message sets. Furthermore, the nature of rapidly deployed VMS is that they are highly mobile, and would need to be changed to reflect conditions as conditions change. Truck mounted, mobile VMS often need to be programmed on-site, meaning drivers/response crews need to have the expertise and/or resources on-hand to program a message appropriate to the situation, severity, and location. The size of a truck-mounted sign is typically only 2 lines, whereas freeway VMS are 3 lines.
The unique nature and uses of truck mounted or other portable VMS, particularly for rapid deployment in response to an incident or emergency, warrants additional study and review of current agency practices and technologies with regard to rapid VMS deployment, MUTCD guidelines for these signs (including use of standardized icons), and the potential for developing message set standards.
There were at the time two response teams that operate within Maricopa County specifically for traffic control/traffic management support during incidents. AZTech’s Regional Emergency Action Coordinating Team (REACT) provided emergency closure, detour and other traffic management support for incidents on arterials in several cities in the County, and ADOT’s ALERT (Arizona Local Emergency Response Team) provides emergency closure and traffic management support for Phoenix metro area freeways. Both of these response groups relied heavily on ITS technologies that could be rapidly deployed, specifically portable and mobile VMS.
Rapidly deploying a technology such as portable VMS for incident conditions required unique applications, approaches and considerations. This project established parameters for an operational definition of ‘rapid deployment of VMS for incident management’ and identify available ‘best practices’ from Maricopa County agencies and other areas that are using rapidly deployed VMS for incident and emergency conditions. Included in this survey were how or when standardized message sets were used for rapid VMS deployment. Available VMS technologies that would typically be used for rapid deployment were reviewed, and specific challenges, limitations, constraints, etc. were identified that could impact development of recommended standards or best practices. The project also looked at how MUTCD provides guidance or standards for this unique and specialized use of portable/mobile VMS. The result was a summary of best practices, special considerations, and recommended practices, technologies and operational uses for rapidly deployed VMS for incident management.
The four tasks required to complete this project included the following:
Task 1: Survey of Literature and Current Practices
A literature search and review of current practices relative to other regions to identify current uses of portable/mobile VMS for incident management was conducted. Any existing practices identified were documented. As part of the survey, agencies were contacted to see if they have current operational practices that involve rapid deployment of VMS signs for incident management that perhaps are not documented in any literature. Potential agencies to contact were identified by MCDOT/AZTech, REACT and ADOT’s ALERT in consultation with ENTERPRISE participants. This survey addressed such items as operational uses or practices, technologies used, message sets, and lessons learned. The results of the literature search and survey were then documented.
Task 2: Assess Portable/Mobile VMS Technology
Available VMS technology that could be used for rapid deployment will be identified and assessed. The purpose of this assessment was to document features and functions of available portable/mobile VMS technology, identify operational requirements (particularly that could affect or hinder rapid deployment), capabilities of the technology (brightness, matrix size), communications requirements, and ability to integrate portable/mobile technologies with incident management practices as well as broader ITS programs. Programming and software requirements were also identified (i.e., programmed on site, ability to use stored message sets, etc.). The results were documented, and included recommended (but not brand specific) technology requirements and features for portable/mobile VMS that are conducive to rapid deployment for incidents.
Task 3: Review of MUTCD Guidance/Criteria
A review of appropriate MUTCD chapters and sections was conducted to see if there was sufficient criteria to address message sets, sign sequence, viewing distance, length and time guidelines, standardized icons, and other aspects, particularly as they relate to the application of portable/mobile VMS for incident management. A new chapter of the MUTCD was developed to specifically address VMS boards, and a draft was obtained (if possible) for review. Applicable MUTCD guidance appropriate for rapidly deployed portable/mobile VMS boards was documented and cited. A potential outcome of this task could have included additional requirements that would need to be addressed as part of a revision to the MUTCD.
Task 4: Final Report
Tasks 1, 2 and 3 were summarized in a final report, to include current status and use of portable/mobile VMS for incident management by agencies, applicable message sets, technology and operational requirements, and ‘best practices’ for operations and ease of integration of this unique technology application into existing practices and programs. Case studies of agencies successfully using this technology were highlighted.
The following products were delivered from this project:
- A summary and report that documents status, technology, and best practices for rapidly deploying VMS for incidents.
- Potential input for a revision to the MUTCD chapter addressing VMS boards for unique requirements of this specific technology application.