Request
For
Information (RFI)
Washington
Metropolitan
Area
Transit
Authority
Transit Signal Priority (TSP) System
Date: March 25, 2011
Transit Signal Priority System RFI
Background/Introduction
Washington Metropolitan Area Transit Authority (WMATA) is contemplating a future
procurement to implement a regional TSP operating system and would like industry information
in order to develop a comprehensive RFP.
The Regional and Strategic Planning branch develops Metro's long-range vision plan and
represents Metro on technical groups to provide information and to influence the studies, plans,
and programs of regional agencies and localities, especially at the Transportation Planning Board
(TPB).
WMATA has developed a regional transit signal priority (TSP) system concept of operations for
the service area to improve the service reliability, efficiency, mobility, and capacity. As an
extension of the concept of operations, TSP system functional requirements have been developed
to outline the framework for the regional system.
WMATA Transit Signal Priority Functional Requirements encompass four areas:
1.
2.
3.
4.
Vehicle detection and communication systems,
Priority request generator,
Priority request server, and
Management and performance monitoring centers.
WMATA intends to implement a TSP system in 2011. The specific schedule, deliverables and
roles and responsibilities are yet to be determined. Vendors are encouraged to provide a “best
practice” solution.
Purpose and Objectives
WMATA seek a regional TSP operating system with the flexibility to be compatible with
existing bus ITS systems, multiple local agency signal systems, and will be able to effectively
and efficiently complete each of the following requirements:
1. Integrate and utilize information on the on-board bus Automatic Vehicle Location
system related to schedule, passenger loading, door status, and other key criteria to
inform priority request generation and service;
2. Follow the distributed system architecture outlined in NTCIP 1211 Scenario 4;
3. Utilize GPS technology to detect equipped buses at user-defined locations or
estimated arrival times;
4. Estimate arrival times to TSP equipped intersections;
5. Integrate with multiple controller cabinet types including but not excluding Type 332,
336, NEMA TS1 Type 1, and NEMA TS2 Type 2 cabinets;
6. Integrate and be compatible with the standard detection detector racks for the
respective controller cabinet types;
Transit Signal Priority System RFI
7. Integrate and communicate with multiple traffic signal controller hardware types
including but not excluding 170, Siemens/Eagle M-50 series, Econolite ASC/2 and
ASC/3, and Type 2070;
8. Integrate and communicate with multiple traffic signal controller software types
including Bi-Trans, SEPAC, Fourth Dimension, and Naztec;
9. Utilize two-way communications over an IEEE 802.11 standard network at 2.4 GHz
band or higher between the vehicle and intersection;
10. Update location or estimated arrival times of equipped buses from the intersection at
predetermined locations or estimated arrival times;
11. Carry out user-defined signal priority strategies at the local intersection controller for
the bus in question;
12. Integrate with queue jump strategies at the local intersection;
13. Terminate the signal priority request once the bus has cleared the stop
bar/intersection, and resume normal signal operations as soon as possible
(coordination should be retained);
14. Record data logs at the intersection and on the vehicle for all vehicle and intersection
communications with user-defined fields, including but not exclusive to vehicle ID,
speed, location, time of priority request, and confirmation of priority request;
15. Compatible and able to integrate with existing preemption systems within the region;
and
16. Compatible and meets all regional agency bench testing requirements and standards.
RFI Response Instructions Interested vendors should review and respond to the RFI. An
overview of the TSP functional requirements is provided in Apendix A to assist contractors in
developing their response.
RFI key dates are as follows, 2:00 pm ET:
March 25, 2011
April 1, 2011
April 6, 2011
April 13, 2011
TBA 2011
RFI made available to the respondents
Deadline for submitting questions
Response to all questions
Deadline to receiving response + supporting
documents
Decision to launch an RFP / Solicitation
All questions related to this RFI should be directed in writing to:
Lily Cheung
Contract Manager
lcheung@wmata.com
Vendors must ensure that your response is delivered to the following address on or before April
13, 2011, 2:00 pm ET with an electronic copy to lcheung@wmata.com:
Transit Signal Priority System RFI
WASHINGTON METROPOLITAN AREA TRANSIT AUTHORITY
600 5th Street, NW
Washington, DC 20001
Room 3D-10
Attn: Lily Cheung
Disclaimer
WMATA does not intend to award a contract on the basis of this RFI or otherwise pay for the
information solicited. This RFI does not constitute a solicitation for proposals for WMATA to
enter into negotiations to award a contract. This RFI is for planning purposes only and shall not
be considered as a request for proposal or as an obligation on the part of WMATA to acquire any
products or services. No entitlement to payment of direct or indirect costs or charges by
WMATA will arise as a result of contractor submission of responses to this RFI or WMATA’s
use of such information. Responses to this RFI will not be returned. Whatever information is
provided in response to this RFI may be used to access tradeoffs and alternatives available for
determining how to proceed with the acquisition. Any proprietary information that is submitted
may be used in establishing requirements but specific contractor submitted information will be
safeguarded as proprietary.
The information, responses received in response to this RFI may be shared with other local and
federal agencies at the discretion of WMATA.
Submittal Requirements
1. Vendor Information
a. Name of person responsible for the information contained in this RFI
b. Title
c. Company Name
d. Date of incorporation
e. Mailing address
f. Telephone number
g. Fax number
h. Email address
i. Web Site
j. Number of employees
k. FY08 – FY11 sales.
2. Name of technology
a. Technology maturity: existing technology, prototype or technology concept
b. Technology summary covering technical approach, operating principles, testing
conducted to date, projected or actual costs, and example commercial sales, if any
c. Number of prior installations of like kind (please include locations of
installations, type of installations, size of installations)
d. Provide three references (include contact name, telephone, email address, type
and size of installation)
Transit Signal Priority System RFI
3. Describe your market share in this industry. Describe percentage of the market share
(both domestically and internationally) your company claim.
4. General Technical information: Describe the following:
a)
b)
c)
d)
e)
f)
g)
h)
i)
GPS accuracy
Speed of the vehicle
Direction of the vehicle
Distance of the transmission, include any issue of interference and the role of signal
attenuation based on distance from the intersection and structures in the line of sight
between transmitter and receiver.
When distance is beyond 1500 feet, what, if any additional roadside access points are
required?
Estimated arrival time to the intersection
Latency (convey information to the intersection within one second)
Does your technology provide the ability for two-way communication (data
transmission from the intersection to the vehicle) between the intersection and the bus
as well as other intersections?
If yes to 4.h., identify whether your technology can receive / display / log the
following data once per second:
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
Intersection identification code
Vehicle identification code
Vehicle speed
Vehicle direction
Confirmation of priority request
Confirmation of priority request received for each priority movement
Request inhibited
Priority status for each priority movement
Vehicle check-in point
Vehicle check-out point
j) Phase status (ie red, yellow, green for each direction of travel at the intersection)
Please feel free to discuss any other features your technology offers that was not previously
covered. Please also address any functionality listed under Overview Functional Requirements
that your technology does not support.
Transit Signal Priority System RFI
APPENDIX A
OVERVIEW OF FUNCTIONAL REQUIREMENTS
The following section is a continuation of the TSP system functional requirements providing
additional guidelines for the TSP system. Under each of the major components, the performance
requirements are prioritized under three tiers correlating to functions that are required (Tier I),
desired based on currently available technology (Tier II), and desired based on anticipated future
technology (Tier III). These tiers provide guidance and flexibility for selecting a TSP
technology. Tier I are the core requirements that the WMATA TSP system operates while Tier II
and Tier III items are optional requirements that will provide a framework on how the TSP
system could expand and meet future needs as the technology becomes available.
Vehicle Location/Detection and Communication Systems
For signal priority to be effective, the location/detection system must place a call at the
appropriate time. If a bus is detected too late, it could result in a missed opportunity to provide
priority. If a bus is detected too early, the request could go unused resulting in undesirable signal
operation adjustments.
Tier I
The following are Tier I characteristics of the vehicle detection and communication systems:
1. Shall utilize a global positioning system (GPS) with a single antenna on the vehicle to
determine vehicle location, speed, and direction.
2. Shall detect and distinguish transit and emergency vehicles from each other and the
general traveling public.
3. Shall be able to operate within an urban environment and maintain a minimum
accuracy of 10 feet (3 meters).
4. Shall be integrated with other on-board systems (primarily WMATA’s AVL system),
using relevant standards.
5. Shall not result in installation of equipment that will create redundant processes.
6. Shall transmit relevant bus information that will be used to prioritize conflicting
priority requests. The message shall be user defined and changeable as needed.
a) Bus Identifier (two bytes)
i) ID (WMATA alpha-numeric coding),
ii) Route
b) Bus Status (one to two bytes)
i) Direction
ii) Speed
iii) Location (Latitude/Longitude coordinates)
Transit Signal Priority System RFI
c) Request varying levels of priority level (e.g., 1-5) – request priority based on
combination of schedule adherence, passenger loading, direction, and route.
d) Check in/check out
e) Position update
f) Door status
g) Bus Estimated time of arrival in seconds (one bit)
7. Shall transmit relevant bus information at no less than once every three (3) seconds.
8. Shall transmit confirmation messages from the priority request server to the priority
request generator that a priority request was received.
9. Shall transmit confirmation messages from the priority request server to the priority
request generator that a priority request was placed to the controller.
10. Shall not exceed one (1) second of latency for the message transmission from the transit
vehicle to the traffic signal controller.
11. Shall communicate wirelessly (IEEE 802.11).
a. Utilize 2.4 and/or 4.9 GHz frequency between the transit vehicle to/from the
intersection.
12. Shall communicate securely with user-defined security encryptions and specifications.
a. Shall be able to identify and configure unique user profiles for administrator,
transit, and agency staff members.
13. Shall be able to configure check-in/check-out locations based on site-specific geometric
conditions.
Tier II
The following should be Tier II characteristics of the vehicle detection and communication
systems:
1. Should create a wireless mesh communication network to enable communications within
the network.
a) Should create a communication medium at the local intersection.
b) Should create a communication medium at the transit vehicle.
2. Should integrate with an existing communications network of any type (fiber, twisted
pair copper, Ethernet over copper, radio, wi-fi) to enable data transfer on a separate
communication medium beyond the select corridor.
Tier III
The following are Tier III characteristics of the vehicle detection and communication systems:
1. Should transmit confirmation messages from the priority request server to the priority
request generator that a priority request was granted.
2. Should transmit traffic controller status data from the priority request server to the
priority request generator after the priority request was generated.
Transit Signal Priority System RFI
Priority Request Generator
The priority request generator is a device that integrates information from the on-board vehicle
devices and the location to determine whether or not to generate a priority request. The use of a
priority request generator allows systems to move beyond unconditional priority requests as
additional data allows the priority request to be a result of protocol operating standards.
Tier I
The following are Tier I characteristics of the priority request generator:
1. Shall be located on the transit vehicle.
2. Shall be integrated with other on-board systems (including at a minimum, WMATA’s
AVL system), using relevant standards.
3. Shall log transit vehicle status (location, speed, heading, and schedule adherence).
4. Shall log all priority requests transmitted to the priority request server.
5. Shall log confirmation messages from the priority request server that a priority request
was received.
6. Shall be able to incorporate transit schedule data to determine if a priority request should
be generated. Further conditional priority logic is described later within this section.
7. Shall transmit a message to the priority request server that the vehicle has departed or
cleared the priority intersection and prompt the intersection to return to normal operations
once the vehicle has cleared.
8. Shall be able to transmit updated vehicle status data to the priority request server multiple
times prior to the priority intersection and check-out point.
Tier II
The following are Tier II characteristics of the priority request generator:
1. Should request limited or no priority at near-side stops.
2. Should be connected to the vehicle doors and/or speedometer to ensure priority is
requested only when doors are closed and/or bus is in motion.
3. Should incorporate the ability to recognize that a bus is sitting in queue at a red signal
and delay the request until the bus is in a closer position to the intersection to take full
advantage of the priority request.
Tier III
The following are Tier III characteristics of the priority request generator:
Transit Signal Priority System RFI
1. Should incorporate data from the automatic passenger counters to allow priority request
to be prioritized based on ridership, or should incorporate data from the fare boxes to
allow priority requests to be prioritized based on collected fares.
2. Should incorporate logic that is connected to the stop request on-board the vehicle. A
priority request would cease when a stop request is activated if the vehicle is approaching
a near-side stop.
Transit Signal Priority Request Server
The transit signal priority server processes and manages all the signal priority/preemption
requests based on conditional logic, and makes a decision on whether signal priority should be
granted, in what manner, and for how long. The server relays output commands to the local
signal controller to establish priority functionality if appropriate.
Tier I
The following are Tier I characteristics of the priority request server:
1. Shall be compatible with the agencies’ traffic signal systems and traffic management
system.
2. Shall process data from priority detection system and conditional priority logic to
determine if and how much priority to grant at the local intersection.
3. Shall be able to validate that data was received from the priority request generator, and
send confirmation message to priority request generator.
4. Shall be capable of processing and prioritizing multiple requests for both priority and
preemption, and prompting the local controller to carry out the most critical function.
5. Shall be able to modify the priority activity based on updated messages from the bus.
6. Shall override all priority requests when a preemption request is registered.
7. Shall log all priority/preemption requests (time, vehicle ID, direction, speed, and vehicle
schedule status) and final action (whether a priority call was initiated or not).
8. Shall process signal priority requests and deliver functional commands to the signal
system at either a centralized or local traffic operations level.
Additionally, for headway-based bus operations, the following are characteristics of the transit
priority request server:
1. Shall store and process arrival time data from priority detection system and conditional
priority logic to determine if and how much priority should be granted at the local
intersection to maintain appropriate headways between vehicles. Conditional priority
logic shall be able to distinguish between multiple routes operating on the same corridor.
2. Shall validate the data transmitted from the approaching vehicle and identify whether the
vehicle in question is authorized in the TSP system or not.
3. Shall enable preemption/priority requests automatically. No driver activations shall be
required or allowed.
Transit Signal Priority System RFI
4. Shall be able to determine whether or not a detected vehicle has departed or cleared the
priority intersection, and prompt the intersection to return to normal operations once the
vehicle has cleared.
Tier II
The following are Tier II characteristics of the priority request server:
1. Should be able to receive data from the traffic signal controller.
2. Should be able to develop an optimized priority/preemption solution based on traffic
signal priority inputs and logic. Optimal plan should minimize impacts to side-street
traffic, while allowing needed benefit to priority/preemption vehicle in question.
3. Should be able to develop an optimized priority/preemption solution based on transit
status data inputs and logic. Optimal plan should maximize efficiencies that will benefit
priority/preemption vehicles in question.
Tier III
The following are Tier III characteristics of the priority request server:
1. Should log traffic signal controller timing parameters (cycle, phase splits, and
coordination point) at time of any priority requests.
Management/Operating Centers
Management centers are necessary to provide transit and traffic monitoring capabilities. Centers
provide the opportunity to update operational strategies in real-time based on system monitoring
or in-field reports. Many of the traffic intersection equipment, such as the traffic signal
controller, detectors, and surveillance cameras, are connected to a management/operating center
through local agency communication infrastructure. Transit equipment, such as buses and AVL
systems, are also connected to a management/operating center but the communication medium
are often radio based. Real-time monitoring is dependent on the communication medium from
the deployed devices to the centers.
Tier I
No Tier I characteristics of the management/operating centers are identified.
Tier II
The following are Tier II characteristics of the management/operating centers:
Transit Signal Priority System RFI
1. Should log all transit vehicle and traffic signal controller data in real-time.
2. Should transmit vehicle status to the management/operating centers in real-time.
3. Should transmit and log priority request generator and server activity in real-time.
Tier III
The following are Tier III characteristics of the traffic signal controller:
1. Should transmit updated transit vehicle schedules and priority strategies to the priority
request generator and server.
2. Should manage transit vehicle location data and transmit the data to user-defined
locations.
Other Transit Signal Priority Functional Requirements
The following lists the general functional requirements of the transit signal priority system:
1. The communications interface of the system shall comply with NTCIP and SAE
standards.
2. Transit signal priority equipment in the field shall be able to communicate with a
laptop or handheld computer for maintenance and monitoring activities in the field.
Local interconnect of displays to the controller shall be handled through the local power supply,
with load switches and conflict monitors provided. Conflict monitors shall meet all pertinent
NEMA standards to assure that conflicting signal indications are not displayed.
Transit Signal Priority System RFI