Traffic Management Center --> ITS Roadway Equipment:
signal priority service request

Definition
Included In
Communication Solutions
Characteristics
Security

Definitions

signal priority service request (Information Flow): A service request for vehicle priority issued to a traffic signal controller. The request includes the priority level, and may include other parameters such as the desired time and duration of service, and the intended travel path through the intersection. This flow also allows the originator to cancel a previously issued request for priority.

Traffic Management Center (Source Physical Object): The 'Traffic Management Center' monitors and controls traffic and the road network. It represents centers that manage a broad range of transportation facilities including freeway systems, rural and suburban highway systems, and urban and suburban traffic control systems. It communicates with ITS Roadway Equipment and Connected Vehicle Roadside Equipment (RSE) to monitor and manage traffic flow and monitor the condition of the roadway, surrounding environmental conditions, and field equipment status. It manages traffic and transportation resources to support allied agencies in responding to, and recovering from, incidents ranging from minor traffic incidents through major disasters.

ITS Roadway Equipment (Destination Physical Object): 'ITS Roadway Equipment' represents the ITS equipment that is distributed on and along the roadway that monitors and controls traffic and monitors and manages the roadway. This physical object 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 ramp metering systems. Lane management systems and barrier systems that control access to transportation infrastructure such as roadways, bridges and tunnels are also included. This object also provides environmental monitoring including sensors that measure road conditions, surface weather, and vehicle emissions. Work zone systems including work zone surveillance, traffic control, driver warning, and work crew safety systems are also included.

Included In

This Triple is in the following Service Packages:

This triple is associated with the following Functional Objects:

This Triple is described by the following Functional View Data Flows:

None

This Triple has the following triple relationships:

None

Communication Solutions

Solutions are sorted in ascending Gap Severity order. The Gap Severity is the parenthetical number at the end of the solution.

Selected Solution

(None-Data) - OASIS MQTT

Solution Description

This solution is used within Australia, Canada and the U.S.. It combines standards associated with (None-Data) with those for OASIS MQTT. The (None-Data) standards include an unspecified set of standards at the upper layers. The OASIS MQTT standards include lower-layer standards that support data distribution of specific types of data.

ITS Application Entity Development needed			Click gap icons for more info.
Mgmt OASIS MQTT DMP	Facilities Development needed OASIS MQTT	Security IP Security Alternatives OASIS MQTT
	TransNet IP Alternatives Internet Transport Alternatives
	Access Internet Subnet Alternatives

Note that some layers might have alternatives, in which case all of the gap icons associated with every alternative may be shown on the diagram, but the solution severity calculations (and resulting ordering of solutions) includes only the issues associated with the default (i.e., best, least severe) alternative.

Characteristics

Characteristic	Value
Time Context	Now
Spatial Context	Local
Acknowledgement	False
Cardinality	Unicast
Initiator	Source
Authenticable	True
Encrypt	False

Interoperability	Description
Local	In cases where an interface is normally encapsulated by a single stakeholder, interoperability is still desirable, but the motive is vendor independence and the efficiencies and choices that an open standards-based interface provides.

Security

Information Flow Security
	Confidentiality	Integrity	Availability
Rating	Not Applicable	Moderate	Low
Basis	There is no sensitive or confidential information within this messages. Additionally, it could be inferred by observing either the presence of a priority-requesting vehicle near an intersection, or the effect on the timing of the intersection. This is also transmitted as a result of broadcast data.	The TMC is transmitting a request to the ITS RE on behalf of a priority-requesting vehicle. It should only be making requests on behalf of an approved vehicle. A corrupted request may lead to a vehicle not receiving a green light after requesting it. In this case, this may lead to traffic delays. If an unapproved vehicle is able to forge these requests, they may cause larger scale traffic delays.	If the ITS RE does not receive any requests, the vehicle may not receive the priority it requested. In the worst case scenario the vehicle would be forced to wait at some lights until they turned green. It would be more useful for a device to support this application, and only have some messages received, than to not support this application at all.

Security Characteristics	Value
Authenticable	True
Encrypt	False

Traffic Management Center --> ITS Roadway Equipment:signal priority service request