Link Type: Center to Field

Traffic Management Center --> ITS Roadway Equipment:
signal control plans

Definition
Included In
Communication Solutions
Characteristics
Security

Definitions

signal control plans (Information Flow): Traffic signal timing parameters including minimum green time and interval durations for basic operation and cycle length, splits, offset, phase sequence, etc. for coordinated systems.

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 in the following Functional Objects:

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

signal_system_timing_plan

This Triple has the following triple relationships:

Relationship	Source	Destination	Flow
Interactive	ITS Roadway Equipment	Traffic Management Center	signal control status

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

EU: UTMC Data - UTMC

Solution Description

This solution is used within the E.U.. It combines standards associated with EU: UTMC Data with those for I-F: UTMC. The EU: UTMC Data standards include upper-layer standards required to implement center-to-field communications using the UTMC Framework. The I-F: UTMC standards include lower-layer standards that support secure center-to-field and field-to-field communications using simple network management protocol (SNMPv2). While SNMPv2 offers some security capabilities, implementations are strongly encouraged to use SNMPv3 to ensure adequate security.

ITS Application Entity UTMC TS004.006			Click gap icons for more info.
Mgmt IETF RFC 1907	Facilities UTMC TS003	Security IETF RFC 9147
	TransNet IETF RFC 768 IP 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	Recent
Spatial Context	Local
Acknowledgement	True
Cardinality	Unicast
Initiator	Source
Authenticable	True
Encrypt	True

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	Moderate	High	Moderate
Basis	Control flows, even for seemingly innocent devices, should be kept confidential to minimize attack vectors. While an individual installation may not be particularly impacted by a cyberattack of its sensor network, another installation might be severely impacted, and different installations are likely to use similar methods, so compromising one leads to compromising all. DISC: THEA believes this to be LOW: "encrypted, authenticated, proprietary; but the result is directly observable from traffic lights	Control flows, even for seemingly innocent devices, should have MODERATE integrity at minimum, just to guarantee that intended control messages are received. Incorrect, corrupted, intercepted and modified control messages can or will result in target field devices not behaving according to operator intent. The severity of this depends on the type of device, which is why some devices are set MODERATE and some HIGH. From THEA: proprietary info that should not be tampered with; tampering with these plans could cause delays along with major safety issues	Control flow availability is related to the criticality of being able to remotely control the device. For most devices, this is MODERATE. For purely passive devices with no incident relationship, this will be LOW. All devices should have default modes that enable them to operate without backhaul connectivity, so no device warrants a HIGH. From THEA: should be timely and readily available; coordinated with other systems; however, should be able to function using a default configuration

Security Characteristics	Value
Authenticable	True
Encrypt	True

Traffic Management Center --> ITS Roadway Equipment:signal control plans