District of Columbia ITS Architecture

Transit Signal Priority Upgrade

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Description

Expand existing signal priority for WMATA vehicles with DDOT signals

Status

Planned

Timeframe

Short

Geographic Scope

Service Scope

Stakeholders

DDOT Transportation Operations Administration

WMATA - Washington Metropolitan Area Transit Authority

Inventory

DDOT TMC

DDOT Traffic Signals

WMATA Bus Operations Control Center

WMATA Transit Vehicles

Services

APTS09-2 - Transit Signal Priority - DDOT / WMATA

Functional Areas

On-board Transit Signal Priority

• The transit vehicle shall determine the schedule deviation and estimated times of arrival (ETA) at transit stops.
• The transit vehicle shall prevent a priority request from being sent when the transit vehicle cannot use the priority (e.g., when the transit vehicle makes a passenger stop on the approach to an intersection).
• The transit vehicle shall send priority requests to traffic signal controllers at intersections, pedestrian crossings, and multimodal crossings on the roads (surface streets) and freeway (ramp controls) network that enable a transit vehicle schedule devia
• The transit vehicle shall send the schedule deviation data and status of priority requests to the transit vehicle operator and provide the capability for the transit vehicle operator to control the priority system.

Roadway Signal Priority

• The field element shall notify controlling traffic management center and maintenance center that the signal timing has changed based on a signal preemption/priority request to help those centers determine whether a fault detected at the signal is a true m
• The field element shall respond to requests for indicator (e.g., signal) priority requests from transit vehicles at intersections, pedestrian crossings, and multimodal crossings.

TMC Multimodal Coordination

• The center shall exchange information with transit management centers including details current transit routes, the level of service on each route, and the progress of individual vehicles along their routes.
• The center shall respond to requests from transit management centers for signal priority at one or more intersections along a particular transit route.

Transit Center Signal Priority

• The center shall analyze transit vehicle schedule performance to determine the need for priority along certain routes or at certain intersections.
• The center shall define business rules that govern use of transit vehicle signal priority, communicate these rules to the transit vehicle, and monitor transit vehicle requests for priority at signalized intersections.
• The center shall provide transit operations personnel with the capability to control and monitor transit signal priority operations.
• The center shall send requests for priority along routes or at intersections to traffic management.

Interfaces

Source	Architecture Flows	Destination
DDOT TMC	signal control data	DDOT Traffic Signals
DDOT TMC	traffic control priority status	WMATA Bus Operations Control Center
DDOT Traffic Signals	request for right-of-way	DDOT TMC
DDOT Traffic Signals	signal control status	DDOT TMC
WMATA Bus Operations Control Center	traffic control priority request	DDOT TMC
WMATA Transit Vehicles	local signal priority request	DDOT Traffic Signals
WMATA Transit Vehicles	transit vehicle schedule performance	WMATA Bus Operations Control Center

Standards

SDO	Document ID	Title	Type
AASHTO/ITE/NEMA	View List	NTCIP Center-to-Center Standards Group	Group
AASHTO/ITE/NEMA	View List	NTCIP Center-to-Field Standards Group	Group
ASTM	View List	Dedicated Short Range Communication at 915 MHz Standards Group	Group
ASTM/IEEE/SAE	View List	Dedicated Short Range Communication at 5.9 GHz Standards Group	Group
AASHTO/ITE/NEMA	NTCIP 1201	Global Object Definitions	Message/Data
AASHTO/ITE/NEMA	NTCIP 1202	Object Definitions for Actuated Traffic Signal Controller (ASC) Units	Message/Data
AASHTO/ITE/NEMA	NTCIP 1210	Field Management Stations (FMS) - Part 1: Object Definitions for Signal System Masters	Message/Data
AASHTO/ITE/NEMA	NTCIP 1211	Object Definitions for Signal Control and Prioritization (SCP)	Message/Data
AASHTO/ITE/NEMA	NTCIP 1214	Object Definitions for Conflict Monitor Units (CMU)	Message/Data
APTA	APTA TCIP-S-001 3.0.3	Standard for Transit Communications Interface Profiles	Message/Data

Operational Concepts

Stakeholder	Roles and Responsibilities
DDOT Transportation Operations Administration
	Provide signal priority for transit vehicles.
WMATA - Washington Metropolitan Area Transit Authority
	Coordinate with the local traffic operations centers for traffic signal priority.