Roadway Subsystem

This subsystem includes the equipment distributed on and along the roadway that monitors and controls traffic and monitors and manages the roadway itself. Equipment includes traffic detectors, environmental sensors, traffic signals, highway advisory radios, dynamic message signs, CCTV cameras and video image processing systems, grade crossing warning systems, and freeway ramp metering systems. HOV lane management, reversible lane management functions, and barrier systems that control access to transportation infrastructure such as roadways, bridges and tunnels are supported, as well as transit priority, and emergency vehicle pre-emption functions. This subsystem also provides the capability for emissions and environmental conditions monitoring including sensors that measure road conditions, surface weather, and vehicle emissions. In adverse conditions, automated systems can be used to apply anti-icing materials, disperse fog, etc. Work zone systems including work zone surveillance, traffic control, driver warning, and work crew safety systems are also included. To enhance security, safeguard systems such as blast shields, exhaust systems and other automated and remotely controlled systems to protect transportation infrastructure is also provided. In advanced implementations, this subsystem supports automated vehicle safety systems by safely controlling access to and egress from an Automated Highway System (AHS) through monitoring of, and communications with, AHS vehicles. Intersection collision avoidance functions are provided by determining the probability of a collision in the intersection and sending appropriate warnings and/or control actions to the approaching vehicles. Advanced sensor systems are supported which provide automated protection for non vehicular road users, and users in such vehicles as bicycles and motorcycles.

Security Considerations

The security considerations for the Roadway Subsystem (RS) are directly related to the types of field equipment that are included in a particular implementation. The RS performs a broad range of roadway network monitoring and control services and includes both safety-critical and non-safety critical systems.

Safety-critical systems include traffic signal systems, gates and barriers that control facility access, and future systems that may support automated vehicle control systems. Since improper operation of these systems can directly endanger motorists, security services should be established so that these systems operate with very high levels of integrity and availability and system operation degrades in a fail-safe manner. In contrast, the information associated with operation of these systems is not confidential and typically will not need special measures to protect it from disclosure.

Surveillance and environmental sensor systems provide information that may be safety critical if this information is used to monitor for incidents or dangerous road conditions. Although malicious tampering is possible, the more likely threats to sensor and surveillance information involve inadvertent loss or corruption of the provided information. Again, availability and integrity are the paramount security objectives. Although the surveillance and sensor data is generally not sensitive to disclosure, confidentially is important when CCTV cameras are zoomed in on a crash and other scenarios where individuals can be identified from the surveillance data.

The driver information systems included in the RS, such as dynamic message signs and highway advisory radio, are generally not considered to be safety-critical, but have their own set of security considerations. These systems are perhaps the most likely in the RS to be the target of unauthorized access attempts and must be protected against such attacks by emphasizing security services that enhance integrity. The availability requirements associated with DMS and HAR may increase as these systems are used increasingly in critical services like Amber Alert.

Other RS systems, including short range communications equipment, will increasingly warrant attention in the future with the advent of VII-enabled safety critical applications. These applications range from probe surveillance to intersection collision avoidance to weather advisory dissemination. Special security considerations will be needed based on the criticality of the supported applications.

Functionality: Equipment Packages and PSpecs

• Advanced Rail Crossing
  
  • 1.1.1.1 - Process Traffic Sensor Data
  • 1.2.7.1 - Process Indicator Output Data for Roads
  • 1.2.7.4 - Process In-vehicle Signage Data
  • 1.6.1.1 - Detect Roadway Events
  • 1.6.1.2.4 - Provide HSR Device Controls
  • 1.6.1.4.1 - Generate Alerts and Advisories
  • 1.6.1.4.3 - Report Alerts and Advisories
  • 1.6.1.5 - Detect HRI Hazards
  • 1.6.1.6.1 - Close HRI on Detection
  • 1.6.1.6.2 - Detect Imminent Vehicle/Train Collision
  • 1.6.3.1 - Interact with Wayside Systems
  • 1.6.3.2 - Advise and Protect Train Crews
  • 1.6.3.3 - Provide ATS Alerts
  • 1.6.5.1 - Provide Interactive Interface
  
  
• Advanced Roadway Mixed Use Sensing
  
  • 1.1.1.7.2 - Process Road User Protection
  • 1.2.7.1 - Process Indicator Output Data for Roads
  
  
• Field Barrier System Control
  
  • 1.2.7.10 - Control Barrier Systems
  
  
• Field Safeguard System Control
  
  • 5.7.6.1 - Control Safeguard Systems
  
  
• Multimodal Crossing Control
  
  • 1.1.1.1 - Process Traffic Sensor Data
  • 1.2.7.1 - Process Indicator Output Data for Roads
  • 1.2.7.5 - Process Indicator Output Data for Freeways
  • 1.2.7.9 - Process Roadway Information Data
  
  
• Roadside Lighting System Control
  
  • 1.2.7.11 - Control Lighting System
  
  
• Roadway Automated Treatment
  
  • 9.2.6.2 - Control Roadway Automated Treatment System
  
  
• Roadway Automated Vehicle Operations
  
  • 3.2.5 - Check Vehicle for Automated Operations Eligibility
  • 3.2.6 - Manage Check-in and Check-out
  • 3.2.8 - Provide Automated Lane Changing
  
  
• Roadway Basic Surveillance
  
  • 1.1.1.1 - Process Traffic Sensor Data
  • 1.3.1.3 - Process Traffic Images
  
  
• Roadway Data Collection
  
  • 1.1.1.4 - Manage Data Collection and Monitoring
  
  
• Roadway Emissions Monitoring
  
  • 1.2.7.9 - Process Roadway Information Data
  • 1.5.5 - Detect Vehicle Emissions Levels
  • 1.5.6 - Detect Pollution Levels
  
  
• Roadway Environmental Monitoring
  
  • 1.1.1.3 - Process Environmental Sensor Data
  
  
• Roadway Equipment Coordination
  
  • 1.1.1.5 - Provide Sensor Interface to Other Roadway Devices
  • 1.2.7.8 - Provide Device Interface to Other Roadway Devices
  
  
• Roadway Field Device Monitoring
  
  • 9.2.3.6 - Collect Field Equipment Status for Repair
  
  
• Roadway Freeway Control
  
  • 1.2.7.2 - Monitor Roadside Equipment Operation for Faults
  • 1.2.7.5 - Process Indicator Output Data for Freeways
  
  
• Roadway HOV Control
  
  • 1.1.1.1 - Process Traffic Sensor Data
  • 1.2.7.5 - Process Indicator Output Data for Freeways
  
  
• Roadway Incident Detection
  
  • 1.1.1.1 - Process Traffic Sensor Data
  • 1.3.1.3 - Process Traffic Images
  
  
• Roadway Infrastructure Monitoring
  
  • 1.1.1.2 - Collect Infrastructure Sensor Data
  
  
• Roadway Intersection Safety Warning
  
  • 1.1.1.1 - Process Traffic Sensor Data
  • 1.2.7.1 - Process Indicator Output Data for Roads
  • 1.2.7.6 - Provide Intersection Collision Avoidance Data
  
  
• Roadway Mixed Use Sensing
  
  • 1.1.1.1 - Process Traffic Sensor Data
  • 1.1.1.7.2 - Process Road User Protection
  • 1.2.7.1 - Process Indicator Output Data for Roads
  • 1.2.7.9 - Process Roadway Information Data
  
  
• Roadway Probe Data Communications
  
  • 1.1.6 - Collect Vehicle Traffic Probe Data
  • 1.1.7 - Collect Vehicle Environmental Probe Data
  
  
• Roadway Reversible Lanes
  
  • 1.1.1.1 - Process Traffic Sensor Data
  • 1.2.7.1 - Process Indicator Output Data for Roads
  • 1.2.7.5 - Process Indicator Output Data for Freeways
  • 1.3.1.3 - Process Traffic Images
  
  
• Roadway Safety Warning System
  
  • 1.1.1.6 - Collect Vehicle Roadside Safety Data
  • 1.1.2.6 - Process Collected Vehicle Safety Data
  • 1.2.7.4 - Process In-vehicle Signage Data
  • 1.2.7.7 - Process Vehicle Safety and Environmental Data for Output
  
  
• Roadway Short Range Traveller Information Communications
  
  • 1.1.2.6 - Process Collected Vehicle Safety Data
  • 1.2.7.4 - Process In-vehicle Signage Data
  • 1.2.7.7 - Process Vehicle Safety and Environmental Data for Output
  • 6.7.3.5 - Provide Short Range Traveller Information
  
  
• Roadway Signal Controls
  
  • 1.1.1.1 - Process Traffic Sensor Data
  • 1.2.7.1 - Process Indicator Output Data for Roads
  • 1.2.7.2 - Monitor Roadside Equipment Operation for Faults
  
  
• Roadway Signal Enforcement
  
  • 1.7.3 - Detect and Classify Signal Violations
  
  
• Roadway Signal Priority
  
  • 1.2.7.1 - Process Indicator Output Data for Roads
  • 1.2.7.3 - Manage Indicator Preemptions
  
  
• Roadway Speed Monitoring
  
  • 1.1.1.1 - Process Traffic Sensor Data
  • 1.2.7.4 - Process In-vehicle Signage Data
  • 1.2.7.9 - Process Roadway Information Data
  • 9.3.3.1 - Collect Vehicle Speed
  • 9.3.3.4 - Support Vehicle Speed Enforcement
  
  
• Roadway Traffic Information Dissemination
  
  • 1.2.7.1 - Process Indicator Output Data for Roads
  • 1.2.7.5 - Process Indicator Output Data for Freeways
  • 1.2.7.9 - Process Roadway Information Data
  
  
• Roadway Variable Speed Limit
  
  • 1.2.7.4 - Process In-vehicle Signage Data
  • 1.7.1 - Post Speed Limit
  
  
• Roadway Warning
  
  • 1.1.1.7.1 - Process Roadway Warning
  
  
• Roadway Work Zone Safety
  
  • 9.3.1.3 - Monitor Crew Movement
  • 9.3.4.1 - Detect Work Zone Intrusion
  • 9.3.4.2 - Provide Work Zone Intrusion Alert
  
  
• Roadway Work Zone Traffic Control
  
  • 1.2.7.10 - Control Barrier Systems
  • 1.2.7.9 - Process Roadway Information Data
  • 1.3.1.3 - Process Traffic Images
  
  
• Standard Rail Crossing
  
  • 1.1.1.1 - Process Traffic Sensor Data
  • 1.2.7.1 - Process Indicator Output Data for Roads
  • 1.6.1.2.1 - Control HRI Traffic Signals
  • 1.6.1.2.2 - Control HRI Warnings and Barriers
  • 1.6.1.2.3 - Provide SSR Device Controls
  • 1.6.1.2.5 - Manage Device Control
  • 1.6.1.2.6 - Maintain Device State
  • 1.6.1.3 - Perform Equipment Self-Test
  • 1.6.1.4.2 - Provide Closure Parameters
  • 1.6.1.4.4 - Report HRI Status on Approach
  • 1.6.1.7.1 - Control Traffic Volume at Active HRI
  • 1.6.1.7.2 - Close HRI on Command
  • 1.6.3.1 - Interact with Wayside Systems
  • 1.6.5.1 - Provide Interactive Interface
  • 1.6.5.2 - Determine HRI Status
  • 1.6.5.3 - Maintain HRI Closure Data
  
  

Inputs/Outputs: Architecture Flows and Data Flows

Archived Data Management Subsystem > Roadway Subsystem

• data collection and monitoring control - Information used to configure and control data collection and monitoring systems.
  Data Flows:
  • roadside_archive_control
  • data_collection_device_control
  
  

Emergency Vehicle Subsystem > Roadway Subsystem

• barrier system control - Information used to configure and control barrier systems that are represented by gates, barriers and other automated or remotely controlled systems used to manage entry to roadways.
  Data Flows:
  • barrier_system_control_from_emerg_veh
  
  
• local signal preemption request - Direct control signal or message to a signalized intersection that results in preemption of the current control plan and grants right-of-way to the requesting vehicle.
  Data Flows:
  • emergency_vehicle_preemptions
  
  

Emissions Management > Roadway Subsystem

• emissions sensor control - Data used to configure and control vehicle emissions sensors.
  Data Flows:
  • vehicle_emissions_sensor_control
  
  
• pollution sensor control - Data used to configure and control area pollution and air quality sensors.
  Data Flows:
  • pollution_sensor_control
  
  

Enforcement Agency > Roadway Subsystem

• traffic enforcement control - Information used to configure and control automated speed monitoring, speed warning, and speed enforcement systems.
  Data Flows:
  • fea-speed_sensor_control
  • fea-enforcement_parameters
  
  

Environment > Roadway Subsystem

• pollutant levels - Atmospheric pollutant levels as monitored by air quality sensors.
  Data Flows:
  • fe-pollutant_levels
  
  

Information Service Provider > Roadway Subsystem

• broadcast traveller information - General traveller information that contains traffic and road conditions, link travel times, incidents, advisories, restrictions, transit service information, weather information, parking information, and other related traveller information.
  Data Flows:
  • field_broadcast_traffic_data
  • field_broadcast_incident_information
  • field_broadcast_multimodal_data
  • field_broadcast_event_information
  • field_broadcast_border_data
  • field_broadcast_weather_data
  • field_broadcast_transit_data
  • field_broadcast_price_data
  • field_broadcast_parking_data
  
  
• emergency traveller information - Public notification of an emergency such as a natural or man-made disaster, civil emergency, or child abduction. This flow also includes evacuation information including evacuation instructions, evacuation zones, recommended evacuation times, tailored evacuation routes and destinations, traffic and road conditions along the evacuation routes, traveller services and shelter information, and reentry times and instructions.
  Data Flows:
  • field_transportation_system_status
  • field_evacuation_traveller_information
  • field_wide_area_alert_information
  • field_emergency_traveller_information
  
  

Maintenance and Construction Field Personnel > Roadway Subsystem

• crew movements - Visual or sensed presence of field crew location within a work zone that is monitored to enhance work zone safety.
  Data Flows:
  • fmcfp-crew_movements
  
  
• field device status request - User input from field personnel requesting operational status of field equipment (sensors, signals, signs, controllers, etc.).
  Data Flows:
  • fmcfp-field_equip_status_request
  
  

Maintenance and Construction Management > Roadway Subsystem

• barrier system control - Information used to configure and control barrier systems that are represented by gates, barriers and other automated or remotely controlled systems used to manage entry to roadways.
  Data Flows:
  • barrier_system_control_from_m_and_c
  
  
• environmental sensors control - Data used to configure and control environmental sensors.
  Data Flows:
  • environmental_sensor_control_for_roadway_sensors
  
  
• infrastructure monitoring sensor control - Data used to configure and control infrastructure monitoring sensors.
  Data Flows:
  • infrastructure_sensor_control_from_m_and_c
  
  
• roadway information system data - Information used to initialize, configure, and control roadside systems that provide driver information (e.g., dynamic message signs, highway advisory radio, beacon systems). This flow can provide message content and delivery attributes, local message store maintenance requests, control mode commands, status queries, and all other commands and associated parameters that support remote management of these systems.
  Data Flows:
  • dms_auto_treat_data_from_maint
  • work_zone_info_for_display
  • har_data_from_m_and_c
  • dms_data_from_m_and_c
  
  
• roadway treatment system control - Control data for remotely located, automated devices, that affect the roadway surface (e.g. de-icing applications).
  Data Flows:
  • roadway_treatment_system_control
  
  
• traffic enforcement control - Information used to configure and control automated speed monitoring, speed warning, and speed enforcement systems.
  Data Flows:
  • speed_sensor_control_from_m_and_c
  
  
• video surveillance control - Information used to configure and control video surveillance systems.
  Data Flows:
  • video_control_from_m_and_c
  
  
• work zone warning device control - Data used to configure and control work zone safety monitoring and warning devices.
  Data Flows:
  • intrusion_detection_device_control
  • intrusion_alert_device_control
  
  

Maintenance and Construction Vehicle > Roadway Subsystem

• barrier system control - Information used to configure and control barrier systems that are represented by gates, barriers and other automated or remotely controlled systems used to manage entry to roadways.
  Data Flows:
  • barrier_system_control_from_mcv
  
  
• environmental sensor data - Current road conditions (e.g., surface temperature, subsurface temperature, moisture, icing, treatment status) and surface weather conditions (e.g., air temperature, wind speed, precipitation, visibility) as measured and reported by fixed and/or mobile environmental sensors. Operational status of the sensors is also included.
  Data Flows:
  • environmental_sensor_data_for_roadway
  
  
• environmental sensors control - Data used to configure and control environmental sensors.
  Data Flows:
  • environmental_sensor_control_for_roadway
  
  
• infrastructure monitoring sensor control - Data used to configure and control infrastructure monitoring sensors.
  Data Flows:
  • infrastructure_sensor_control_from_mcv
  
  
• roadway information system data - Information used to initialize, configure, and control roadside systems that provide driver information (e.g., dynamic message signs, highway advisory radio, beacon systems). This flow can provide message content and delivery attributes, local message store maintenance requests, control mode commands, status queries, and all other commands and associated parameters that support remote management of these systems.
  Data Flows:
  • dms_data_from_mcv
  
  

Meteorological Service Provider > Roadway Subsystem

• environmental sensors control - Data used to configure and control environmental sensors.
  Data Flows:
  • fmsp-roadway_env_sensor_control
  
  

Multimodal Crossings > Roadway Subsystem

• multimodal crossing status - Indication of operational status and pending requests for right-of-way from equipment supporting the non-highway mode at multimodal crossings.
  Data Flows:
  • fmmc-crossing_status_for_highways
  • fmmc-crossing_close_time
  • fmmc-crossing_close_duration
  • fmmc-crossing_status_for_roads
  
  

National Meteorological Service > Roadway Subsystem

• environmental sensors control - Data used to configure and control environmental sensors.
  Data Flows:
  • fnms-roadway_env_sensor_control
  
  

Other Roadway > Roadway Subsystem

• roadway equipment coordination - The direct flow of information between field equipment. This includes transfer of information between sensors and driver information systems (e.g., DMS, HAR) or control devices (e.g., traffic signals, ramp meters), direct coordination between adjacent control devices, interfaces between detection and warning or alarm systems, and any other direct communications between field equipment. This includes information exchanged between a Signal System Master (SSM) and the Signal System Local (SSL) equipment.
  Data Flows:
  • fors-sensor_status
  • fors-device_control
  • fors-device_status
  • fors-roadway_info_data_from_devices
  • fors-sensor_control
  • fors-roadway_info_data_from_sensors
  • fors-sensor_data
  
  

Pedestrians > Roadway Subsystem

• crossing call - Pedestrian request to cross the roadway. This may be an overt (e.g., push button) request from a pedestrian or the physical presence of a pedestrian that can be detected by sensors or surveillance systems.
  Data Flows:
  • fp-pedestrian_images
  • fp-pedestrian_data
  
  
• non-vehicular presence - Sensed presence of pedestrians and other non-motor vehicle travellers at roadway crossing or control points.
  Data Flows:
  • fp-pedestrian_presence
  
  

Potential Obstacles > Roadway Subsystem

• physical presence - Detection of an obstacle by a vehicle. Obstacle could include animals, other vehicles, pedestrians, rocks in roadway etc.
  Data Flows:
  • From_Potential_Obstacles
  
  

Roadway Environment > Roadway Subsystem

• environmental conditions - Current road conditions (e.g., surface temperature, subsurface temperature, moisture, icing, treatment status) and surface weather conditions (e.g., air temperature, wind speed, precipitation, visibility) that are measured by environmental sensors.
  Data Flows:
  • fre-roadway_infrastructure_characteristics
  • fre-physical_conditions
  • fre-environmental_conditions
  
  
• environmental hazards - Detection of specific localized hazards affecting the roadway, like mud slides, avalanches, high winds and flooding.
  Data Flows:
  • fre-roadway_environmental_hazards
  
  
• roadway characteristics - Detectable or measurable road characteristics such as friction coefficient and general surface conditions, road geometry and markings, etc. These characteristics are monitored or measured by ITS sensors and used to support advanced vehicle safety and control and road maintenance capabilities.
  Data Flows:
  • fre-roadway_characteristics
  
  

Roadway Subsystem > Archived Data Management Subsystem

• probe archive data - Probe data that allows calculation of travel times, volumes, and other measures that support transportation planning. Optionally, this flow also includes origin and destination information for vehicles that opt to provide this information.
  Data Flows:
  • traffic_probe_data_from_vehicles_archive_data
  
  
• roadside archive data - A broad set of data derived from roadside sensors that includes current traffic conditions, environmental conditions, and any other data that can be directly collected by roadside sensors. This data also indicates the status of the sensors and reports of any identified sensor faults.
  Data Flows:
  • roadside_archive_data
  • data_collection_device_status
  
  

Roadway Subsystem > Basic Vehicle

• broadcast advisories - General broadcast advisories that are provided over wide-area wireless communications direct to the vehicle radio. These analog advisory messages may provide similar content to ITS broadcast information flows, but include no digital data component. Existing Highway-Advisory Radio (HAR) advisory messages are a prime example of this flow.
  Data Flows:
  • tbv-har_broadcast
  
  

Roadway Subsystem > Driver

• driver information - General advisory and traffic control information provided to the driver while en route.
  Data Flows:
  • td-ramp_state_indication
  • td-work_zone_intrusion_alert
  • td-signal_indication
  • td-lane_use_indication_for_roads
  • td-intersection_safety_data
  • td-dms_indication
  • td-lane_use_indication_for_highways
  
  
• driver roadway warning - Warning information provided to the driver based on dynamic sensing of localized factors affecting safe roadway usage.
  Data Flows:
  • td-road_warning_for_driver
  
  
• variable speed limit - Legally enforceable speed limit information presented to a driver that can be varied as appropriate for roadway and weather conditions.
  Data Flows:
  • td-speed_limit_for_driver
  
  

Roadway Subsystem > Emergency Vehicle Subsystem

• barrier system status - Current operating status of barrier systems. Barrier systems represent gates, barriers and other automated or remotely controlled systems used to manage entry to roadways. Status of the systems includes operating condition and current operational state.
  Data Flows:
  • barrier_system_status_to_emerg_veh
  
  

Roadway Subsystem > Emissions Management

• area pollution data - Measured air quality data, including measured levels of atmospheric pollutants including ozone, particulate matter, carbon monoxide, and nitrogen oxides, and operational status of the sensors.
  Data Flows:
  • pollution_sensor_data
  • pollution_sensor_status
  
  
• vehicle emissions data - Measured emissions of specific vehicles comprised of exhaust pollutants including hydrocarbons, carbon monoxide, and nitrogen oxides.
  Data Flows:
  • vehicle_emissions_sensor_status
  • vehicle_emissions_alert
  • vehicle_emissions_sensor_data
  
  

Roadway Subsystem > Enforcement Agency

• traffic enforcement information - System status including current operational state and logged information including measured speeds, warning messages displayed, and violation records.
  Data Flows:
  • tea-speed_sensor_status
  
  
• traffic violation notification - Notification to enforcement agency of a detected traffic violation including speed violations and HOV violations.
  Data Flows:
  • tea-signal_violation_log_data
  • tea-signal_violation_video_data
  • tea-signal_violation_detection_data
  • tea-speed_violation_notification
  
  

Roadway Subsystem > Information Service Provider

• environmental probe data - Data from vehicle safety and convenience systems that can be used to estimate environmental conditions, including measured air temperature, exterior light status, wiper status, sun sensor status, rain sensor status, traction control status, anti-lock brake status, and other collected vehicle system status and sensor information. The collected data is reported along with the location, heading, and time that the data was collected. Both current data and snapshots of recent events (e.g., traction control or anti-lock brake system activations) may be reported.
  Data Flows:
  • vehicle_env_probe_data_for_isp
  • vehicle_env_probe_status_for_isp
  
  
• short range communications status - Status of the short range communications equipment including the current state or mode of operation and the current equipment status.
  Data Flows:
  • trav_info_equip_status_for_isp_operator
  
  
• traffic probe data - Vehicle data that is used to determine traffic conditions. In a basic implementation, the data could be limited to time stamped unique identifiers that can be used to measure a vehicle’s progress through the network. In more advanced implementations, the vehicle may report current position, speed, and heading and snapshots of recent events including route information, starts and stops, speed changes, and other information that can be used to estimate traffic conditions.
  Data Flows:
  • vehicle_traffic_probe_status_for_isp
  • vehicle_traffic_probe_data_for_isp
  
  

Roadway Subsystem > Maintenance and Construction Field Personnel

• field device status presentation - Presentation of operational status of field equipment (sensors, signals, signs, controllers, etc.) to field personnel.
  Data Flows:
  • tmcfp-field_equip_status
  
  
• work zone warning - Warnings provided to maintenance and construction field personnel, indicating a work zone emergency or safety issue such as the intrusion of a vehicle into the work zone area or movement of field crew into the travel lanes.
  Data Flows:
  • tmcfp-work_zone_intrusion_warning
  • tmcfp-work_zone_intrusion_alert
  
  

Roadway Subsystem > Maintenance and Construction Management

• barrier system status - Current operating status of barrier systems. Barrier systems represent gates, barriers and other automated or remotely controlled systems used to manage entry to roadways. Status of the systems includes operating condition and current operational state.
  Data Flows:
  • barrier_system_status_to_m_and_c
  
  
• environmental probe data - Data from vehicle safety and convenience systems that can be used to estimate environmental conditions, including measured air temperature, exterior light status, wiper status, sun sensor status, rain sensor status, traction control status, anti-lock brake status, and other collected vehicle system status and sensor information. The collected data is reported along with the location, heading, and time that the data was collected. Both current data and snapshots of recent events (e.g., traction control or anti-lock brake system activations) may be reported.
  Data Flows:
  • vehicle_env_probe_data_for_maint
  • vehicle_env_probe_status_for_maint
  • vehicle_env_probe_data_for_infrastructure_maint
  
  
• environmental sensor data - Current road conditions (e.g., surface temperature, subsurface temperature, moisture, icing, treatment status) and surface weather conditions (e.g., air temperature, wind speed, precipitation, visibility) as measured and reported by fixed and/or mobile environmental sensors. Operational status of the sensors is also included.
  Data Flows:
  • environmental_sensor_status_from_roadway_sensors
  • environmental_sensor_data_from_roadway_sensors
  
  
• field device status - Reports from field equipment (sensors, signals, signs, controllers, etc.) which indicate current operational status.
  Data Flows:
  • field_equip_status_for_m_and_c
  
  
• infrastructure monitoring sensor data - Data read from infrastructure-based sensors that monitor the condition or integrity of transportation infrastructure including bridges, tunnels, interchanges, pavement, culverts, signs, transit rail or guideway, and other roadway infrastructure. Includes sensor data and the operational status of the sensors.
  Data Flows:
  • infrastructure_sensor_status_for_m_and_c
  • infrastructure_sensor_data_for_m_and_c
  
  
• roadway information system status - Current operating status of dynamic message signs, highway advisory radios, beacon systems, or other configurable field equipment that provides dynamic information to the driver.
  Data Flows:
  • dms_auto_treat_status_to_maint
  • har_status_for_m_and_c
  • dms_status_for_m_and_c
  
  
• roadway treatment system status - Current operational status of automated roadway treatment devices (e.g., anti-icing systems).
  Data Flows:
  • roadway_treatment_system_status
  
  
• traffic enforcement information - System status including current operational state and logged information including measured speeds, warning messages displayed, and violation records.
  Data Flows:
  • speed_data_for_m_and_c_speed_monitoring
  • speed_sensor_log_for_m_and_c
  • speed_violation_notification_for_m_and_c
  • speed_sensor_status_for_m_and_c
  
  
• traffic images - High fidelity, real-time traffic images suitable for surveillance monitoring by the operator or for use in machine vision applications. This flow includes the images and the operational status of the surveillance system.
  Data Flows:
  • video_device_status_for_m_and_c
  • work_zone_images
  
  
• violation detection - Roadside detection of a vehicle violating a speed limit, traffic signal, or control signage.
  Data Flows:
  • speed_violation_notification_for_m_and_c
  
  
• work zone warning status - Status of a work zone safety monitoring and warning devices. This flow documents system activations and includes additional supporting information (e.g., an image) that allows verification of the alarm.
  Data Flows:
  • intrusion_alert_device_status
  • roadside_crew_warning_given
  • work_zone_intrusion_alert
  • intrusion_detection_device_status
  • work_zone_intrusion_video_image
  • work_zone_intrusion_detected
  
  

Roadway Subsystem > Maintenance and Construction Vehicle

• barrier system status - Current operating status of barrier systems. Barrier systems represent gates, barriers and other automated or remotely controlled systems used to manage entry to roadways. Status of the systems includes operating condition and current operational state.
  Data Flows:
  • barrier_system_status_to_mcv
  
  
• environmental sensor data - Current road conditions (e.g., surface temperature, subsurface temperature, moisture, icing, treatment status) and surface weather conditions (e.g., air temperature, wind speed, precipitation, visibility) as measured and reported by fixed and/or mobile environmental sensors. Operational status of the sensors is also included.
  Data Flows:
  • environmental_sensor_status_from_roadway
  • environmental_sensor_data_from_roadway
  
  
• infrastructure monitoring sensor data - Data read from infrastructure-based sensors that monitor the condition or integrity of transportation infrastructure including bridges, tunnels, interchanges, pavement, culverts, signs, transit rail or guideway, and other roadway infrastructure. Includes sensor data and the operational status of the sensors.
  Data Flows:
  • infrastructure_sensor_status_for_mcv
  • infrastructure_sensor_data_for_mcv
  
  
• roadway information system status - Current operating status of dynamic message signs, highway advisory radios, beacon systems, or other configurable field equipment that provides dynamic information to the driver.
  Data Flows:
  • dms_status_for_mcv
  
  
• work zone warning notification - Notification of a work zone emergency or safety issue. This flow identifies that a work zone emergency or safety issue has occurred so that warnings may be generated by more than one system in the work zone.
  Data Flows:
  • work_zone_intrusion_detection_for_on_board
  
  

Roadway Subsystem > Map Update Provider

• traffic probe data - Vehicle data that is used to determine traffic conditions. In a basic implementation, the data could be limited to time stamped unique identifiers that can be used to measure a vehicle’s progress through the network. In more advanced implementations, the vehicle may report current position, speed, and heading and snapshots of recent events including route information, starts and stops, speed changes, and other information that can be used to estimate traffic conditions.
  Data Flows:
  • tmup-traffic_probe_data
  
  

Roadway Subsystem > Meteorological Service Provider

• environmental probe data - Data from vehicle safety and convenience systems that can be used to estimate environmental conditions, including measured air temperature, exterior light status, wiper status, sun sensor status, rain sensor status, traction control status, anti-lock brake status, and other collected vehicle system status and sensor information. The collected data is reported along with the location, heading, and time that the data was collected. Both current data and snapshots of recent events (e.g., traction control or anti-lock brake system activations) may be reported.
  Data Flows:
  • tmsp-vehicle_env_probe_status
  • tmsp-vehicle_env_probe_data
  
  
• environmental sensor data - Current road conditions (e.g., surface temperature, subsurface temperature, moisture, icing, treatment status) and surface weather conditions (e.g., air temperature, wind speed, precipitation, visibility) as measured and reported by fixed and/or mobile environmental sensors. Operational status of the sensors is also included.
  Data Flows:
  • tmsp-roadway_env_sensor_status
  • tmsp-roadway_env_sensor_data
  
  

Roadway Subsystem > Multimodal Crossings

• highway control status - Current traffic control equipment status that indicates operational status and right-of-way availability to the non-highway transportation mode at a multimodal crossing.
  Data Flows:
  • tmmc-highway_equipment_status
  • tmmc-crossing_clear_at_roads
  • tmmc-road_equipment_status
  • tmmc-stop_alternate_mode_at_highways
  • tmmc-stop_alternate_mode_at_roads
  • tmmc-crossing_clear_at_highways
  
  

Roadway Subsystem > National Meteorological Service

• environmental probe data - Data from vehicle safety and convenience systems that can be used to estimate environmental conditions, including measured air temperature, exterior light status, wiper status, sun sensor status, rain sensor status, traction control status, anti-lock brake status, and other collected vehicle system status and sensor information. The collected data is reported along with the location, heading, and time that the data was collected. Both current data and snapshots of recent events (e.g., traction control or anti-lock brake system activations) may be reported.
  Data Flows:
  • tnms-vehicle_env_probe_status
  • tnms-vehicle_env_probe_data
  
  
• environmental sensor data - Current road conditions (e.g., surface temperature, subsurface temperature, moisture, icing, treatment status) and surface weather conditions (e.g., air temperature, wind speed, precipitation, visibility) as measured and reported by fixed and/or mobile environmental sensors. Operational status of the sensors is also included.
  Data Flows:
  • tnms-roadway_env_sensor_data
  • tnms-roadway_env_sensor_status
  
  

Roadway Subsystem > Other Roadway

• roadway equipment coordination - The direct flow of information between field equipment. This includes transfer of information between sensors and driver information systems (e.g., DMS, HAR) or control devices (e.g., traffic signals, ramp meters), direct coordination between adjacent control devices, interfaces between detection and warning or alarm systems, and any other direct communications between field equipment. This includes information exchanged between a Signal System Master (SSM) and the Signal System Local (SSL) equipment.
  Data Flows:
  • tors-device_control
  • tors-roadway_info_data_from_devices
  • tors-roadway_info_data_from_sensors
  • tors-sensor_control
  • tors-sensor_status
  • tors-sensor_data
  • tors-device_status
  
  

Roadway Subsystem > Pedestrians

• crossing permission - Signal to pedestrians indicating permission to cross roadway.
  Data Flows:
  • tp-dms_indication
  • tp-cross_road
  • tp-cross_request_received
  
  

Roadway Subsystem > Traffic Management

• automated roadway status - Current operational status of an automated vehicle operations facility, including the status of the field equipment and vehicles using the facility.
  Data Flows:
  • avo_checking_details
  • avo_device_status
  
  
• barrier system status - Current operating status of barrier systems. Barrier systems represent gates, barriers and other automated or remotely controlled systems used to manage entry to roadways. Status of the systems includes operating condition and current operational state.
  Data Flows:
  • barrier_system_status
  • barrier_system_device_status
  
  
• environmental sensor data - Current road conditions (e.g., surface temperature, subsurface temperature, moisture, icing, treatment status) and surface weather conditions (e.g., air temperature, wind speed, precipitation, visibility) as measured and reported by fixed and/or mobile environmental sensors. Operational status of the sensors is also included.
  Data Flows:
  • environment_sensor_data
  • environmental_sensor_status
  
  
• freeway control status - Current operational status and operating parameters for ramp meters, mainline metering/lane controls and other control equipment associated with freeway operations.
  Data Flows:
  • indicator_input_data_from_highways
  • indicator_status_from_highways
  
  
• HOV data - Current HOV lane information including both standard traffic flow measures and information regarding vehicle occupancy in HOV lanes, and operational status of the HOV monitoring equipment.
  Data Flows:
  • hov_lane_data_input
  • hov_sensor_data
  • hov_sensor_status
  
  
• HRI status - Status of the highway-rail intersection equipment including both the current state or mode of operation and the current equipment condition.
  Data Flows:
  • rail_operations_message
  • hri_traffic_data
  • hri_status
  • hri_guidance_for_roadway_info
  • traffic_management_request
  
  
• intersection blockage notification - Notification that a highway-rail intersection is obstructed and supporting information.
  Data Flows:
  • intersection_blocked
  • hri_blockage
  
  
• lighting system status - Status of roadside lighting controls including operating condition and current operational state.
  Data Flows:
  • lighting_system_device_status
  • lighting_system_status
  
  
• request for right-of-way - Forwarded request from signal prioritization, signal preemption, pedestrian call, multi-modal crossing activation, or other source for right-of-way.
  Data Flows:
  • multimodal_crossing_sensor_status
  • pedestrian_sensor_status
  • signal_override_status
  • multimodal_crossing_sensor_data
  • pedestrian_sensor_data
  
  
• reversible lane status - Current reversible lane status including traffic sensor and surveillance data and the operational status and mode of the reversible lane control equipment.
  Data Flows:
  • reversible_lane_sensor_data
  • reversible_lane_sensor_status
  • reversible_lane_control_device_status_from_roads
  • reversible_lane_control_device_status_from_highways
  • reversible_lane_video_images
  
  
• road user protection data - Current data as well as operational status
  Data Flows:
  • road_user_protection_video_for_traffic
  • road_user_protection_device_status
  • road_user_protection_data_for_traffic
  
  
• roadway information system status - Current operating status of dynamic message signs, highway advisory radios, beacon systems, or other configurable field equipment that provides dynamic information to the driver.
  Data Flows:
  • dms_status
  • har_status
  
  
• roadway warning data - Information provided to roadway systems that support the dissemination of roadway warnings to vehicles and drivers, based on local road hazard conditions.
  Data Flows:
  • road_warning_device_status
  • road_warning_traffic_data
  
  
• safeguard system status - Current operating status of safeguard systems (remotely controlled equipment used to mitigate the impact of incidents on transportation infrastructure, such as blast shields, exhaust systems, etc.). Status of the systems includes operating condition and current operational state.
  Data Flows:
  • safeguard_system_status
  • safeguard_system_device_status
  
  
• short range communications status - Status of the short range communications equipment including the current state or mode of operation and the current equipment status.
  Data Flows:
  • vehicle_sign_status
  
  
• signal control status - Status of surface street signal controls including operating condition and current operational state.
  Data Flows:
  • indicator_status_from_roads
  • indicator_input_data_from_roads
  
  
• traffic enforcement information - System status including current operational state and logged information including measured speeds, warning messages displayed, and violation records.
  Data Flows:
  • speed_sensor_status
  • speed_violation_notification_for_traffic
  • speed_data_for_traffic_speed_monitoring
  • speed_sensor_log_for_traffic
  
  
• traffic flow - Raw and/or processed traffic detector data which allows derivation of traffic flow variables (e.g., speed, volume, and density measures) and associated information (e.g., congestion, potential incidents). This flow includes the traffic data and the operational status of the traffic detectors.
  Data Flows:
  • incident_analysis_data
  • traffic_image_data
  • traffic_sensor_data
  • traffic_sensor_status
  
  
• traffic images - High fidelity, real-time traffic images suitable for surveillance monitoring by the operator or for use in machine vision applications. This flow includes the images and the operational status of the surveillance system.
  Data Flows:
  • video_device_status
  • incident_video_image
  • traffic_video_image_for_display
  • traffic_video_image
  
  
• traffic probe data - Vehicle data that is used to determine traffic conditions. In a basic implementation, the data could be limited to time stamped unique identifiers that can be used to measure a vehicle’s progress through the network. In more advanced implementations, the vehicle may report current position, speed, and heading and snapshots of recent events including route information, starts and stops, speed changes, and other information that can be used to estimate traffic conditions.
  Data Flows:
  • vehicle_traffic_probe_data_for_traffic
  • vehicle_traffic_probe_equip_status
  
  
• violation detection - Roadside detection of a vehicle violating a speed limit, traffic signal, or control signage.
  Data Flows:
  • signal_violation_video_data
  • speed_violation_notification_for_traffic
  • signal_violation_log_data
  • signal_violation_detection_data
  
  

Roadway Subsystem > Vehicle

• access permission - Information returned indicating whether permission for access is granted and instructions for proceeding.
  Data Flows:
  • vehicle_barrier_access_status
  
  
• automated vehicle control data - Instructions and control parameters for automated vehicle operation including current system conditions and advisories, control parameters (e.g., speed and performance profiles, headways), maneuver coordination, and check in/checkout instructions.
  Data Flows:
  • lane_change_details
  • lane_change_strategy
  • avo_check_response
  
  
• broadcast traveller information - General traveller information that contains traffic and road conditions, link travel times, incidents, advisories, restrictions, transit service information, weather information, parking information, and other related traveller information.
  Data Flows:
  • field_to_vehicle_broadcast_price_data
  • field_to_vehicle_broadcast_border_data
  • field_to_vehicle_broadcast_traffic_data
  • field_to_vehicle_broadcast_event_information
  • field_to_vehicle_broadcast_incident_information
  • field_to_vehicle_broadcast_transit_data
  • field_to_vehicle_broadcast_multimodal_data
  • field_to_vehicle_broadcast_parking_data
  • field_to_vehicle_broadcast_weather_data
  
  
• emergency traveller information - Public notification of an emergency such as a natural or man-made disaster, civil emergency, or child abduction. This flow also includes evacuation information including evacuation instructions, evacuation zones, recommended evacuation times, tailored evacuation routes and destinations, traffic and road conditions along the evacuation routes, traveller services and shelter information, and reentry times and instructions.
  Data Flows:
  • field_to_vehicle_evacuation_traveller_information
  • field_to_vehicle_emergency_traveller_information
  • field_to_vehicle_wide_area_alert_information
  • field_to_vehicle_transportation_system_status
  
  
• intersection status - Intersection status including current operational status, signal phase and timing information, intersection geometry, surface conditions, warnings of potential violations or hazardous conditions, and approaching vehicle information. This may include information about the position, velocity, acceleration, and turning status of approaching vehicles.
  Data Flows:
  • intersection_collision_avoidance_data
  • intersection_status_data_for_vehicle
  
  
• roadway safety data - Information about potential safety hazards in the vehicle path such as stalled vehicles, wrong way drivers, debris, or standing water.
  Data Flows:
  • roadside_safety_data_to_vehicle
  
  
• vehicle signage data - In-vehicle signing data that augments regulatory, warning, and informational road signs and signals. The information provided would include static sign information (e.g., stop, curve warning, guide signs, service signs, and directional signs) and dynamic information (e.g., current signal states, grade crossing information, local traffic and road conditions, advisories, and detours).
  Data Flows:
  • intrusion_alert_for_in_vehicle_signing
  • vehicle_signage_data
  • vehicle_env_probe_data_output
  • vehicle_signage_emissions_testing_results
  
  

Roadway Subsystem > Wayside Equipment

• HRI operational status - Status of the highway-rail grade crossing equipment including both the current state or mode of operation and the current equipment condition.
  Data Flows:
  • twe-hri_status
  
  
• intersection blockage notification - Notification that a highway-rail intersection is obstructed and supporting information.
  Data Flows:
  • twe-stop_highway_indication
  • twe-stop_train_indication
  
  

Traffic > Roadway Subsystem

• traffic characteristics - Physical traffic characteristics which are monitored and translated into macroscopic measures like occupancy, volume, density, and average speed. Point measures support presence detection and individual vehicle measures like speed.
  Data Flows:
  • ftrf-traffic_data
  • ftrf-traffic_images
  • ftrf-vehicle_pollutant_levels
  • ftrf-vehicle_presence
  
  

Traffic Management > Roadway Subsystem

• automated roadway control data - Control commands and operating parameters provided to field equipment that controls and monitors automated vehicle operations.
  Data Flows:
  • avo_control_data_changes
  • automated_lane_changing_control_data
  
  
• barrier system control - Information used to configure and control barrier systems that are represented by gates, barriers and other automated or remotely controlled systems used to manage entry to roadways.
  Data Flows:
  • barrier_system_control
  
  
• environmental sensors control - Data used to configure and control environmental sensors.
  Data Flows:
  • env_sensor_control_to_roadway
  
  
• freeway control data - Control commands and operating parameters for ramp meters, mainline metering/lane controls and other systems associated with freeway operations.
  Data Flows:
  • indicator_control_monitoring_data_for_highways
  • indicator_control_data_for_highways
  
  
• HRI control data - Data required for HRI information transmitted at railroad grade crossings and within railroad operations.
  Data Flows:
  • rail_operations_advisories
  • rail_operations_device_command
  • indicator_sign_control_data_for_hri
  • hri_traffic_surveillance
  
  
• HRI request - A request for highway-rail intersection status or a specific control request intended to modify HRI operation.
  Data Flows:
  • tms_requests
  • rail_operations_requests
  
  
• lighting system control data - Information used to configure and control roadside lighting systems.
  Data Flows:
  • lighting_system_control
  
  
• reversible lane control - Control of automated reversible lane configuration and driver information systems.
  Data Flows:
  • reversible_lane_control_for_roads
  • reversible_lane_control_for_highways
  
  
• road user protection device control - Current data as well as operational status and operating parameters for mixed roadway and righ-of-way systems.
  Data Flows:
  • road_user_protection_device_configuration
  
  
• roadway information system data - Information used to initialize, configure, and control roadside systems that provide driver information (e.g., dynamic message signs, highway advisory radio, beacon systems). This flow can provide message content and delivery attributes, local message store maintenance requests, control mode commands, status queries, and all other commands and associated parameters that support remote management of these systems.
  Data Flows:
  • dms_data
  • dms_control_data
  • dms_wide_area_alert_information
  • har_wide_area_alert_information
  • har_data
  
  
• roadway warning device control - Information used to configure and control roadway warning devices
  Data Flows:
  • road_warning_sensor_configuration
  
  
• safeguard system control - Data that controls safeguard systems (remotely controlled equipment used to mitigate the impact of incidents on transportation infrastructure, such as blast shields, exhaust systems, etc.).
  Data Flows:
  • safeguard_system_control
  
  
• signal control data - Information used to configure and control traffic signal systems.
  Data Flows:
  • indicator_control_monitoring_data_for_roads
  • indicator_control_data_for_roads
  
  
• signal violation device control - Information used to configure and control signal violation detection devices.
  Data Flows:
  • signal_violation_parameter_settings
  
  
• speed limit setting - Information used to configure and control variable speed limit devices.
  Data Flows:
  • traffic_speed_limit_setting
  
  
• traffic enforcement control - Information used to configure and control automated speed monitoring, speed warning, and speed enforcement systems.
  Data Flows:
  • speed_sensor_control_from_traffic
  
  
• traffic sensor control - Information used to configure and control traffic sensor systems.
  Data Flows:
  • sensor_configuration_data
  
  
• vehicle signage data - In-vehicle signing data that augments regulatory, warning, and informational road signs and signals. The information provided would include static sign information (e.g., stop, curve warning, guide signs, service signs, and directional signs) and dynamic information (e.g., current signal states, grade crossing information, local traffic and road conditions, advisories, and detours).
  Data Flows:
  • vehicle_sign_data
  
  
• video surveillance control - Information used to configure and control video surveillance systems.
  Data Flows:
  • incident_video_image_control
  
  

Transit Vehicle Subsystem > Roadway Subsystem

• local signal priority request - Request from a vehicle to a signalized intersection for priority at that intersection.
  Data Flows:
  • transit_vehicle_roadway_priorities
  
  

Vehicle > Roadway Subsystem

• access request - Request for access to an access-controlled transportation facility.
  Data Flows:
  • vehicle_barrier_access_request
  
  
• automated vehicle status - Data provided by an automated vehicle identifying it's current mode and operational status, current position and motion, preferred route, and information provided to support checking/checkout and coordinated maneuvers while on the automated facility.
  Data Flows:
  • avo_route_data
  • avo_vehicle_condition
  
  
• environmental probe data - Data from vehicle safety and convenience systems that can be used to estimate environmental conditions, including measured air temperature, exterior light status, wiper status, sun sensor status, rain sensor status, traction control status, anti-lock brake status, and other collected vehicle system status and sensor information. The collected data is reported along with the location, heading, and time that the data was collected. Both current data and snapshots of recent events (e.g., traction control or anti-lock brake system activations) may be reported.
  Data Flows:
  • vehicle_env_probe_data
  
  
• probe archive data - Probe data that allows calculation of travel times, volumes, and other measures that support transportation planning. Optionally, this flow also includes origin and destination information for vehicles that opt to provide this information.
  Data Flows:
  • vehicle_traffic_probe_data_for_archive
  • vehicle_guidance_probe_data_for_archive
  
  
• traffic probe data - Vehicle data that is used to determine traffic conditions. In a basic implementation, the data could be limited to time stamped unique identifiers that can be used to measure a vehicle’s progress through the network. In more advanced implementations, the vehicle may report current position, speed, and heading and snapshots of recent events including route information, starts and stops, speed changes, and other information that can be used to estimate traffic conditions.
  Data Flows:
  • vehicle_traffic_probe_data
  • vehicle_guidance_probe_data
  
  
• vehicle diagnostics data - Information about the vehicle and its current operational status that supports vehicle performance monitoring, service, and repair. The flow identifies the vehicle and vehicle type and provides information about the vehicle's current operational status, the current performance of engine-related components, and notification of any identified malfunctions.
  Data Flows:
  • vehicle_status_details_for_emissions
  
  
• vehicle intersection safety data - Vehicle path and acceleration data provided by vehicles approaching or occupying an intersection. It identifies the intersection, vehicle position and motion, the anticipated lane and movement that will be used in the intersection, and notification of potential violations or other detected safety hazards.
  Data Flows:
  • vehicle_status_for_intersection
  
  
• vehicle occupancy - The number of occupants detected by the vehicle.
  Data Flows:
  • vehicle_occupants_detected
  
  
• vehicle safety data - Vehicle safety data indicating vehicle location, vehicle motion (speed, heading, acceleration), vehicle control (brakes, steering, throttle, exterior lights), basic vehicle characteristics (length, width). May also include additional vehicle status (e.g., anti-lock brake activation, stability control system activation).
  Data Flows:
  • vehicle_roadside_safety_data
  
  

Vehicle Characteristics > Roadway Subsystem

• vehicle characteristics - The physical or visible characteristics of an individual vehicle that can be measured to classify a vehicle and imaged to uniquely identify a vehicle.
  Data Flows:
  • From_Vehicle_Characteristics
  
  

Wayside Equipment > Roadway Subsystem

• arriving train information - Information for a train approaching a highway-rail intersection that may include direction and allow calculation of approximate arrival time and closure duration.
  Data Flows:
  • fwe-train_data
  
  
• track status - Current status of the wayside equipment and notification of an arriving train.
  Data Flows:
  • fwe-approaching_train_announcement
  • fwe-wayside_equipment_status