Work Zone Mobility and Safety Program

Appendix A. National ITS Architecture

The National ITS Architecture provides a framework for planning, designing, and integrating ITS. It provides important standards for hardware components and software that will allow for integration with other systems. The architecture includes:

  • Function – what the system will do;
  • Location – where the information will reside; and
  • Integration – path that allows information to flow among the physical components.

The use of ITS in work zones has grown to the point that steps have been taken toward its inclusion in the National ITS Program Plan and the National ITS Architecture 7.0.47 The work zone related portions of the National Architecture can help to define the functionality of the work zone system and are also useful in developing functional specifications.

The Maintenance And Construction Operations (MCO) User Service Description features work zone management and safety as one of its main functional areas. The MCO User Service underscores the value of work zone information and smart work zones when states and regions establish regional ITS architectures for ITS deployment. MCO User Service functional areas include:

  • Maintenance Vehicle Fleet Management: monitors and tracks locations and conditions of fleets of maintenance, construction, and specialized service vehicles
  • Roadway Management: monitors and forecasts conditions and manages treatment of roadways during various travel conditions
  • Work Zone Management and Safety: supports effective and efficient roadway operations during work zone activities
  • Roadway Maintenance Conditions and Work Plan Dissemination: coordinates work plans and communicates conditions

MCO User Service Requirements that pertain to work zone management and safety are:

8.1.3 Maintenance and Construction Operations shall provide a Work Zone Management and Safety (WZMS) function, which provides support for the effectiveness, safety, and efficiency of roadway operations during all work zone activities. This function includes interactions among Traffic Managers, Supervisors, Dispatchers, Field Crews, Construction Crews, Public Safety Organizations, Information Service Providers, and Travelers. WZMS shall monitor, control, and direct activity in the vicinity of work zones. WZMS shall provide information about work zones, including but not limited to: Anticipated delays Alternate routes Suggested speed limit WZMS shall provide support for automated speed enforcement around work zones. WZMS shall be able to divert vehicles around work zones via automated lane changing techniques. WZMS shall collect information used to support automated lane changing, including but not limited to: Volume Occupancy Speed Headways Vehicle characteristics Merging distance WZMS shall support archiving of field data. WZMS shall support use of field data for developing AHS-merging strategies. WZMS shall support the management of data about work zones. WZMS shall collect information concerning work zone activities, including but not limited to: Location Nature / type Scheduled start time Duration Lane shifts Staging areas Length of work zone Scheduled phases of work zone configuration Alternate routes Anticipated delays for travel route Anticipated delays for diversion route WZMS shall correlate planned activities with actual work. WZMS shall support preparation of reports on work zone activities. WZMS shall provide information on work zone activities to other agencies, including but not limited to: Other maintenance and construction operations systems Commercial vehicle fleets Emergency vehicle fleets Traveler information systems Traffic management systems WZMS shall provide systems that communicate reliable, accurate, and timely traveler information, including but not limited to: Location, including lane closure information Alternate route / detour Work zone speed limit Delay WZMS shall support the provision of vehicle intrusion warnings. WZMS shall be capable of tracking individual crew movements.

47For more information about the National ITS Architecture, see

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