Module 40 - A309a

A309a: Understanding User Needs for Ramp Meter Control (RMC) Units Based on NTCIP 1207 v02 Standard

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Slide 1:

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Slide 3:

Slide 4:

A309a:

Understanding User Needs for Ramp Meter Control (RMC) Units Based on NTCIP 1207 v02 Standard

Slide 5:

Instructor

Raman K. Patel, Ph.D., P.E. President

RK Patel Associates, Inc.

New York City, NY, USA

Slide 6:

Target Audience

• Traffic management and engineering staff
• Traffic Management Center/operations staff
• Freeway and traffic signal maintenance staff
• System developers
• Private and public sectors users including manufacturers

Slide 7:

Recommended Prerequisite(s)

• I101: Using ITS Standards: An Overview
• A101: Introduction to Acquiring Standards-based ITS Systems
• A102: Introduction to User Needs Identification
• A201: Details On Acquiring Standards-based ITS Systems
• A202: Identifying and Writing User Needs When ITS Standards Do Not Have SE Content
• A103: Introduction to ITS Standards Requirements Development
• A203: Writing Requirements When ITS Standards Do Not Have SE Content
• C101: Introduction to the Communications Protocols and Their Uses in ITS Applications

Slide 8:

Curriculum Path

(Extended Text Description: Curriculum Path: A graphical illustration indicating the sequence of training modules that lead up to and follow each course. Each module is represented by a box with the name of the module in it and an arrow showing the logical flow of the modules and the current module highlighted. This slide focuses on the modules that lead up to the current course. The modules include: I101: Using ITS Standards: An Overview, A101: Introduction to Acquiring Standards-based ITS Systems, A102: Introduction to User Needs Identification, A201: Details On Acquiring Standards-based ITS Systems, A202: Identifying and Writing User Needs When ITS Standards Do Not Have SE Content, A103: Introduction to ITS Standards Requirements Development, A203: Writing Requirements When ITS Standards Do Not Have SE Content, C101: Introduction to the Communications Protocols and Their Uses in ITS Applications, A309a Understaning User Needs for Ramp Meter Control (RMC) Units Based on NTCIP 1207 Standard v02. The last box is highlighted indicating the current module.)

Slide 9:

Learning Objectives

1. Review the structure of the NTCIP 1207 v02 Standard
2. Identify RMC-specific operational needs
3. Prepare well-written user needs for RMC units
4. Explain how to evaluate conformance to the RMC Standard

Slide 10:

Learning Objective #1: Review the Structure of the NTCIP 1207 v02 Standard

• Definition of a ramp meter, reference layout, and architecture
• The NTCIP family of standards
• Purpose of the NTCIP 1207 v02 Standard
• Components of the NTCIP 1207 v02 Standard
• What is new in the v02 Standard?

Slide 11:

Learning Objective #1

Terminology

• Ramp Meter is a traffic controller (Type 170 or 2070 or ATC) equipped with software/firmware and algorithms specific to a freeway ramp to control (to meter) traffic flow entering freeway lanes
• Ramp Metering is a rate expressed in vehicle per hour per lane (vphpl), at which vehicles are allowed to proceed through the metered lane signal (release rate)

Example: A ramp meter will allow 500 vph per lane (vphpl) release rate

(Extended Text Description: Author's relevant notes: Terminology: Ramp Meter is a traffic controller (Type 170 or 2070 or ATC) equipped with software/firmware and algorithms specific to a freeway ramp to control (meter) traffic flow entering freeway lanes. To the right of this definition, a photo of a traffic controller appears. The cabinet of the controller is open and it shows the inside components. The source of this controller is Caltrans. Ramp Metering is a rate expressed in vehicle-per-hour per lane (vphpl), at which vehicles are allowed to proceed through the metered lane signal (release rate). Example: A ramp meter will allow 500 vph per lane (vphpl) release rate.)

Source: Caltrans

Slide 12:

Learning Objective #1

Ramp Metering Control (RMC) Unit

• RMC is a system in which the entry of vehicles onto a freeway from an on-ramp is controlled by a traffic signal, allowing a fixed number of vehicles to enter from each metered lane of the on-ramp during each cycle
• RMC Unit consists of the field controller, its suite of sensors, its warning signs and signals, and stop bar pavement marking

(Extended Text Description: Author's relevant notes: Ramp Metering Control (RMC) Unit: The slide has a layout with detailed components of the RMC unit. Three detectors on mainline are shown as small square boxes with three outbound arrows for each lane showing direction of traffic flow. On the metered lane, several detectors are shown on a ramp with the inward arrow going towards the freeway mainline, labeled a queue detector. Demand detector and passage detector are the last ones after the STOP line. To the right, a warning sign- ramp meter is on when flashing appears. Another small yellow sign on the ramp side reads "Ramp Meter Ahead.")

Slide 13:

Learning Objective #1

RMC Architecture Diagram

(Extended Text Description: Author's relevant notes: RMC Architecture Diagram is a page taken from the RMC standard that show details where this standard applies. At the top, a TMC Central TMS system is shown with a ring where three PC tower servers are shown. This is connected with a solid line to an RMC unit. The RMC Control-module is in a square box and the solid line is shown as the NTCIP-subject matter of this NTCIP 1207 v02 Standard. At the right side of the slide, TMC is shown as connected to other TMCs with TMDD and NTCIP 2304 C2C Standards.)

Slide 14:

Learning Objective #1

ITS Architecture

Traffic Metering Service Package (ATMS04)

(Extended Text Description: Author's relevant notes: ITS Architecture: Traffic Metering Service Package (ATMS04) is shown with data flows and a red square box highlights ramp metering data flows between TM and Roadway. This conveys that this standard supports the ITS Architecture service package.)

Source: National ITS Architecture v7 2012 http://www.iteris.com

Slide 15:

Learning Objective #1

NTCIP Framework

(Extended Text Description: NTCIP Framework: This slide shows a graphic of the communication levels of the NTCIP standards. The bottom level is the called the Plant Level and includes boxes for Dial-up, Fiber, Coax, Wireless, Twisted Pair, and Leased Line. The next higher level is called the Subnetwork Level and includes PPP, Ethernet, and PMPP. The next level is called the Transport Level and includes TCP/IP, UDP/IP, and T2/NULL. The next level is called the Application Level and includes C2C XML, DATEX, FTP, TFTP, SNMP, and STMP. The next level is called the Information Level and includes C2C Messages, Files, Data Objects, and Dynamic Objects. These boxes are connected to an overarching box, also in the Information Level, labeled Functional Area Data Dictionaries with the left hand side identifying C2C Data Dictionaries and the right hand side labeled NTCIP Data Dictionaries. On the right side corner there is a vertical text box that reads NTCIP 1201 Global Objects and NTCIP 1207 RMC unit, which points to Information Level Data Dictionaries. Underneath, the arrow points to SNMP at Application level. This is shown to emphasize where these standards are located. On the left a text box with an arrow points to TOP level-Information level.)

Source: NTCIP Guide

Slide 16:

Learning Objective #1

NTCIP 1207 v02 Standard Basics

• This standard assumes a mode of operation in which the RMC unit possesses intelligence, and data used for ramp management and data collection is resident at the RMC unit
• We refer to the RMC unit's status, control, and configuration data as the "controller database"; the standard specifies interfaces whereby this data can be manipulated by the central system

(Extended Text Description: Author's relevant notes: NTCIP 1207 v02 Standard Basics: The top Traffic controller photo is from Caltrans and shows an open door. It is connected to a TMC photo below with a two- headed blue arrow. The set up thus conveys that a TMC is connected to an RMC unit in the field.)

Slide 17:

Learning Objective #1

Benefits of ITS Standards

(Extended Text Description: Author's relevant notes: Benefits of ITS Standards: There are five photo images of ITS devices connected to a TMC with NTCIP, using a two headed arrow. The image of TMC is at the top. Below, the first connected device is shown as a CCTV camera; next, a blank DMS sign; then, a Type 170 traffic controller followed by an ATC cabinet. The last photo shows an ATC as a replacement of the Type 170 with two arrows to convey that 170 can be interchangeable with ATC. This graphical setup brings up compatibility among devices, interoperability, and finally interchangeability as benefits.)

Slide 18:

Learning Objective #1

Components of the NTCIP 1207 v02 Standard

These sections provide general information about RMC units:

• SECTION 1 General
  • Scope, references, terms, definitions
• SECTION 2 Standard-Based RMC Systems
  • Benefits of standardization
• SECTION 3 Management Information Base (MIB)
  • RMC objects by functions
  • Abstract Syntax Notation 1 (ASN.1) Format

Slide 19:

Learning Objective #1

What is New in the NTCIP 1207 v02 Standard?

• New SECTION 4 RMC BLOCK OBJECT DEFINITIONS

(Special objects to achieve transmission efficiency)

• New Annexes:

ANNEX A RMC UNIT OPERATIONS DESCRIPTION

ANNEX B PROTOCOL REQUIREMENTS LIST (PRL) Conformance Groups (CGs)

ANNEX C OBJECT TREE

ANNEX D (FUTURE TEST PROCEDURES)

ANNEX E DOCUMENT REVISIONS

Slide 20:

Learning Objective #1

What is NOT offered by the NTCIP 1207 v02 Standard?

(Extended Text Description: Author's relevant notes: What is not offered by the NTCIP 1207 v02 Standard? This slide shows a slanted part of a Vee diagram on the left that outlines Concept of Operations, Requirements, and Design. Two separate arrows lead to User Needs and Requirements to indicate that the user needs and requirements sections are not offered by this standard. Design is shown at the bottom as the MIB provides design.)

Slide 21:

Slide 22:

Learning Objective #1

Which of the following statements is FALSE as applied to the NTCIP 1207 v02 Standard?

Answer Choices

1. Standard is independent of the type of the ramp traffic controller
2. MIB provides design objects for RMC functions
3. RMC user needs are listed
4. Ramp metering module resides in the traffic controller

Slide 23:

Learning Objective #1

Review of Answers

a) Standard is independent of the type of the ramp traffic controller
Incorrect. The standard is independent of the type of controller used as a ramp meter.

b) MIB provides design objects for RMC functions
Incorrect. The MIB does provide design objects.

c) RMC user needs are listed
Correct! The statement is indeed a FALSE; RMC user needs are not listed.

d) Ramp metering module resides in the traffic controller
Incorrect. Each ramp meter has a metering module in it.

Slide 24:

Summary of Learning Objective #1

Review the Structure of the NTCIP 1207 v02 Standard

• Defined an RMC unit and the components, and have reviewed layout and system architecture
• Reviewed the NTCIP family of standards and benefits
• Reviewed the purpose, structure of the standard, and key components
• Reviewed what is new in the v02 Standard

Slide 25:

Learning Objective #2

Learning Objective #2: Identify RMC-Specific Operational Needs

• What are your operational needs and why?
• How does the RMC Standard cover operational needs for freeway management applications?
  • Command sources (manual, communications, interconnect, default) and priorities
  • Communications actions (fixed rate, traffic responsive, corridor-wide coordinated)
• Identify key features from NTCIP 1207 v02 Standard Annex-A: RMC Operational Description

Slide 26:

Learning Objective #2

What are your Operational Needs and Why?

Analyzing Concept of Operations (ConOps) for Needs

• ConOps document reveals a "big picture":
  • What is the current situation or problem?
  • Who are the users? Who is affected?
  • What are the operational scenarios?
  • Are there any corridor-wide or regional aspects?

(Extended Text Description: Author's relevant notes: What are your Operational Needs and Why? There is title page of a ConOps report with a photo showing a roadway.)

Slide 27:

Learning Objective #2

Sources of Operational Needs

• Agency documentation:
  • Development plan
  • Design documents
  • Architecture and subsystem requirements

(Extended Text Description: Author's relevant notes: Sources of Operational Needs: Three report title pages are shown: The first report, Ramp Metering Development Plan, shows an image of a roadway with a metering lane operation. The second report title page is Ramp Meter Design Manual and the third, Operating Guidelines for TxDOT Ramp Control Signals.)

Slide 28:

Learning Objective #2

Additional Sources of RM Practice Information

(Extended Text Description: Author's relevant notes: Additional sources of RM Practice Information: Two handbooks from USDOT are shown on this slide. The first handbook shows the title page, Ramp Management and Control, with an image of a roadway with cars.)

https://ops.fhwa.dot.gov/publications/ramp_mgmt_handbook/manual/manual/pdf/rm_handbook.pdf

(Extended Text Description: Author's relevant notes: Additional sources of RM Practice Information: Two handbooks from USDOT are shown. The second handbook shows the title page, Freeway Management and Operations Handbook.)

http://ops.fhwa.dot.gov/freewaymgmt/publications/frwy_mgmt_handbook/report_info.htm

Slide 29:

Learning Objective #2

Operational Needs

Balance Freeway Capacity Demand by Controlling On-Ramp Traffic

• Achieving greater efficiency with:
  • Improved freeway flow
  • Increased freeway speed
  • Reduced overall travel time
• Achieving safety improvements with:
  • Reduction in overall freeway accidents
  • Providing smoother, safer merging

Source: WSDOT

Slide 30:

Learning Objective #2

Operational Needs (cont.)

• Improving Traffic Incident Management (TIM) practice with:
  • Reduced clearance time
  • Coordination within the corridor
  • Roadway closures and detours management

(Extended Text Description: Operational needs: A freeway segment with both directions is shown with an incident on the outbound right side, closing all three moving lanes. On the other side, traffic is also blocked by an emergency vehicle.)

Source: FHWA

Slide 31:

Learning Objective #2

Summary of Operational Outcomes/Benefits

Slide:	Efficiency Benefits
Operating Agency	Flow Volume Increase	Average Speed Increase	Travel Time Reduction
Detroit, MI	+ 14%	+8%
Long Island, NY	+9%	+35%	-20%
Minneapolis, MN	+25%	+16%	-6 to -16%
Portland, OR		+173%
Seattle, WA	+74%		-52%

Source: FHWA RM Handbook

Slide 32:

Learning Objective #2

Summary of Safety Outcomes/Benefits

	Safety Benefits
Operating Agency	Merging Accident Decrease
Detroit, MI	-50%
Long Island, NY	-15%
Minneapolis, MN	-24%
Portland, OR	-43%
Seattle, WA	-39%

Source: FHWA RM Handbook

(Extended Text Description: Author's relevant notes: Summary of Safety Outcomes-Benefits: A small graphic of a roadway section is on the right side of the table that shows entering vehicles from a ramp merging area. The point is illustrated that near the merge area, collisions do occur and ramp metering helps prevent them. Safety benefits are provided in second column of the table, with first column listing cities.)

Source: Ministry of Transportation, Canada

Slide 33:

Learning Objective #2

Operational Actions

Agencies Implement Metering Strategies to Influence Outcomes (Benefits)

• Balance demand (entering ramp traffic) and capacity (mainline flow)
• Implement metering actions:
  1. Fixed rate is a preplanned release rate determined using historical data or periodic field observations.
  2. Traffic responsive rate is calculated or selected based on the current measured conditions on the mainline
     • Local traffic responsive (one ramp)
  3. System-wide traffic responsive is a strategy to control ramps in a section-corridor using a central system algorithm (adaptive metering)

Slide 34:

Learning Objective #2

Fixed Rate Metering Action

Regulate Traffic On-Ramp Based on the Historical Data with Fixed Rate Metering (Time of Day or Pre-Timed)

(Extended Text Description: Author's relevant notes: Fixed Rate Metering Action: This slide has two photos; the first photo shows ONE Metered Lane from MTC-CA to depict a 240-50vphpl rate.)

Source: MTC-CA

ONE Metered Lane 240-900 vph for single lane

(Extended Text Description: Author's relevant notes: Fixed Rate Metering Action: This slide has two photos; the second photo shows two lane operations also from MTC-CA that shows a 400-1700 vphpl rate.)

Source: MTC-CA

TWO Metered Lanes 400-1700 vph for dual-lane

Data Source: Freeway M&O Handbook

Slide 35:

Learning Objective #2

Traffic Responsive Action

(Extended Text Description: Author's relevant notes: Traffic Responsive Action: Under the top text box, which reads, Regulate Traffic On-Ramp with a Traffic Responsive Metering Plan, Developed Based on Real-Time Data (Occupancy, Flow Rate, Speed), a detector layout on mainline is shown with outbound arrows per lane. Arrows are shown on an on-ramp from a queue detector towards demand and passage detectors.)

Slide 36:

Learning Objective #2

Traffic Responsive Terminology

• A metering plan is a preconfigured look up table
• Each plan contains several metering levels
• Each level provides the suitable metering rate to respond to the current condition
• Mainline detectors report current occupancy
• Current occupancy is compared with the stored threshold data set for occupancy, flow rate, and speed, providing a metering rate

(Extended Text Description: Author's relevant notes: Traffic Responsive Terminology: A small box shows a detector station on mainline to illustrate occupancy data generation.)

Slide 37:

Learning Objective #2

Illustration of Traffic Responsive Scenario

(Extended Text Description: Illustration of Traffic Responsive Scenario: A photo to the left of a table in the center of the slide shows a roadway section with cars at about 8 a.m. The photo to the right shows another roadway with more traffic at 9 a.m. The table presents various occupancy percentage in the first column and metering rate in the second column. Two arrows are pointing to a 20 percent occupancy on the left and 31 percent occupancy on the left. Both show the metering rate (8 and 4 respectively). Thus, we are showing how occupancy at a specific time will determine what rate will be computed by the RMC at that time. The data in the table is as follows:

Occupancy (%)	Metering Rate (Vehicles/Minute)
<= 10	12
11-16	10
17-22	8
23-28	6
29-34	4
>34	3

)

Summary: Example shows that RMC unit provided two metering levels.

Levels are thus "Presets".

Slide 38:

Learning Objective #2

How Does the RMC Standard Cover Operational Needs?

(Extended Text Description: Author's relevant notes: How Does the RMC Standard Cover Operational Needs? This slide has two photos on left side, one in the middle, and two on right side. The top left photo shows loop detectors that feed data to RMC unit shown in the middle photo. A TMC is shown at bottom left side, connected to RMC in center with a two headed arrow. The photo on the top right shows one car per green. Below, a three-head signal is shown and thebottom a photo is of a Meter ON sign. All six photos together provide an indication of the management of RMC functions.)

Slide 39:

Learning Objective #2

How Does the RMC Standard Cover Operational Needs? (cont.)

(Extended Text Description: Author's relevant notes: How Does the RMC Standard Cover Operational Needs? (cont.) In this slide, four photos appear: A TMC on the top left with a one-headed arrow connecting to the RMC unit in the middle. A laptop at bottom also shown connecting to the RMC unit in the middle. A traffic controller on the top right is making a connection to the RMC unit with two-headed arrow, and to the right is the text that indicated Time Base Control (Scheduled-Holidays Special Events).)

Slide 40:

Learning Objective #2

How Does the RMC Standard Cover Operational Needs? (cont.)

Using a Third Party Software, Communications Command Source Remotely Exchanges Data With the RMC Unit:

• To inquire about current configuration and change configuration
• To control functions-parameters (requests "action")
• To monitor operations-conditions (requests "data")

(Extended Text Description: Author's relevant notes: How Does the RMC Standard Cover Operational Needs? (cont.) In this slide we are showing two photos. The photo on the left is the same TMC as before and the photo on the right is of the traffic controller. Both are connected with two-headed arrow. A small detector station layout located above the traffic controller is shown with a one- way connection to the TMC. The detector station is also connected to the traffic controller.)

Slide 41:

Learning Objective #2

Identify Key Features (User Needs) from the NTCIP 1207 Annex A

1. Freeway Segment:

• Number of lanes
• Lane's ID number
• Mainline detectors (volume, speed, occupancy)
• Upstream station-Downstream station

2. ON-Ramp Operation:

• Number of metered lanes
• Lane's ID number
• Detectors (demand, queue, passage)
• Advanced warning signs and control
• Traffic responsive plans-N
• Metering levels-N
• Signal service-green/yellow/red

Slide 42:

Learning Objective #2

Identify Key Features (User Needs) from the NTCIP 1207 Annex A (cont.)

3. Command Sources:

• Manual
• Communications
• Interconnect
• Time-base control
• Default

4. Command Actions:

• Fixed rate
• Traffic responsive
• Rest-in-dark
• Rest-in-green

Slide 43:

Slide 44:

Learning Objective #2

Which of the following is a FALSE statement related to traffic responsive operation?

Answer Choices

1. A TMC operator can remotely retrieve traffic flow data
2. Communications command source has the highest priority
3. Metering levels are part of a metering plan table
4. RMC-module is located within the RMC unit

Slide 45:

Learning Objective #2

Review of Answers

a) A TMC operator can remotely retrieve traffic flow data
Incorrect. The statement is true.

b) Communications command source has the highest priority
Correct! The statement is FALSE. Manual command source has the highest priority, followed by the communications source command.

c) Metering levels are part of a metering plan table
Incorrect. The statement is true.

d) RMC-module is located within the RMC unit
Incorrect. The statement is true.

Slide 46:

Summary of Learning Objective #2

Identify RMC-Specific Operational Needs

• We have reviewed the RMC-specific operational needs and why
• Reviewed how the standard covers priority-based mechanism for command sources such as manual or communications for controlling an RMC unit
• Discussed communications actions including fixed rate, traffic responsive, and corridor-wide
• Identified key RMC user needs from the Annex A operational descriptions

Slide 47:

Learning Objective #3: Prepare Well-Written User Needs for RMC Units

• User needs do not exist for the RMC Standard and agencies must develop them for the acquisition process
• Explain how user needs are extracted and written for RMC procurement
• Discuss what to do if certain user needs are not met by the RMC Standard

Slide 48:

Learning Objective #3

What is a User Need?

• A user need is a description (a statement in a specification) of what the RMC system should do to support operations: Features/Functions
  • Example: A TMC operator needs to make a request to the RMC unit to change the current ramp metering rate...
• As a first step, users must first identify this user need and then write it for an RMC unit specification

Slide 49:

Learning Objective #3

Criteria for Writing a "Well-Written" User Need

When writing a user need, one must remember that it addresses an operational problem and describe it using the following recommended criteria:

1. Provide a structure by assigning a unique number and title to make it uniquely identifiable.
2. Identify (one or more) major desired capability (MDCs) by including a function(s) or feature(s) you desire from the device/system.
3. Capture the rationale by stating why it is needed by the user.
4. Keep it solution-free: Do not get into how to meet it (design).

Slide 50:

Learning Objective #3

Applying the Criteria: Example

UN #1 Change a Metering Rate uniquely identifiable

A TMC operator (management station) has a need to make a request to the RMC unit to change the current ramp metering rate (Major Desired Capability) to a new metering rate in order to meet current traffic flow conditions (Rationale) on a freeway segment.

This should be done by providing....... Solution-Free

Slide 51:

Learning Objective #3

Where Do We Find RMC User Needs?

• Explore the following sources for user needs:
  • Operational needs: Agency metering policy and freeway traffic management ConOps
  • NTCIP 1207 v02 Annex A RMC unit operations description (provides functionality-key features details)
  • NTCIP 1207 v02 Annex B conformance groups (provides groupings of related objects)
  • Common (generic) architectural user needs from the SEP-based NTCIP 1204 v03 ESS Standard (Annex F)

Slide 52:

Learning Objective #3

Advice on How to Use Information Sources

Annex B CGs Cover RMC Functionality

• Read the annex to gain an insight into RMC features (functions)
• Understand how CGs act as a traceability tool for user needs and functionality
• Note how each CG lists design objects needed for a specification

Annex A Descriptions Explain RMC Operations

• Read the annex to gain better understanding of the RMC operational parameters
• Operations descriptions are inconsistent with SEP-based user needs, but they do discuss RMC parameters which we need for a specification

Slide 53:

Learning Objective #3

Suggestion for User Needs Organization

Types of RMC User Needs

• Architectural user needs for general communication capabilities
• Features (Functions) desired from the RMC unit
• Special local project needs not addressed above

RMC User Needs

2.0 Background Information

2.1 Architectural User Needs (generic)

2.1.1 Provide Live Data Exchange

2.1.2 Provide Off-Line Logged Data

2.1.3 Provide Retrieval Capability

2.2 Features (Functions)

2.2.1 Managing Configuration

2.2.2 RMC unit Control

2.2.3 Monitoring Status

2.3 Supplemental Needs

2.3.1 (if applicable)

Note: Section 2 and UN ID are shown as illustration

Slide 54:

Learning Objective #3

Approach to Architectural User Needs

Based on NTCIP 1204 v03 ESS Standard Annex F

UN 2.1.1: Provide Live Data Exchange

A management station (central software) has a need to conduct a live data exchange with the RMC unit to retrieve any set of data at any time.

UN 2.1.2: Provide Logged Data Exchange

A management station has a need to log data and to retrieve data at a later time from the RMC unit in a situation when communication is lost or is not always on communication (e.g. dial-up links).

UN 2.1.3: Provide Capability to Retrieve RMC Identity

A TMC Operator desires to inquire basic information about the RMC unit such as its location, make, model, and version of the device components.

MDCs are shown in green text

(Note: for this slide, the green text is bold and underlined)

Slide 55:

Learning Objective #3

Approach to Finding User Needs from Annex A

(Extended Text Description: Text box on left containing text Step1: Identify sections with two blue arrows pointing to two other text boxes.
The top text box on the right contains the following text with checkmarks in front of each line:
A. 5.1 Fixed Rate
A. 8.3 Meeting operation, signal intervals
A. 9 Queue override
The bottom box on the right contains the text with checkmarks in front of each line:
A. 5.2 Traffic responsive metering
A. 7.1 Metering plan
A. 7.2 Metering rate
A. 8.3 Metering operation-signal intervals
Below that, a text box contains the text: Step 2: Use writing criteria: Provide IS, MDC, rationale, and solution-free.)

Slide 56:

Learning Objective #3

Finding User Needs from Annex A and Applying Writing Criteria

(Extended Text Description: In this slide, there is a text box that contains the following text: UN 2.4 Fixed Rate - The agency desires to implement a fixed metering rate selected by the central system (or locally) based on a Time of Day Schedule to control ramp traffic for each metered lane. Currently, the agency intends to assign the left lane as priority (HOV) lane and the right lane as a common lane.

A curved arrow below the paragraph connects the text "Unique ID" to "UN 2.4 Fixed Rate" in the paragraph above. A curved arrow below the paragraph connects the text "Rationale" to "each metered lane" in the paragraph above. A curved arrow below the paragraph connects the text "Solution-free" to "priority (HOV) lane" in the paragraph above. A curved arrow below the paragraph connects the text "MDC" to "fixed metering" in the paragraph above.)

Slide 57:

Learning Objective #3

Finding User Needs from Annex A and Applying Writing Criteria (cont.)

(Extended Text Description: In this slide, there is a text box that contains the following text: UN 2.5 Queue Override - The agency desires to implement a queue override operation, in the event that the occupancy of a queue detector reaches a certain threshold by increasing (faster) metering rate to flush the ramp traffic to cut delays.

A curved arrow below the paragraph connects the text "Unique ID" to "UN 2.5 Queue Override" in the paragraph above. A curved arrow below the paragraph connects the text "Rationale" to "flush" in the paragraph above. A curved arrow below the paragraph connects the text "Solution-free" to "increasing (faster) metering" in the paragraph above. A curved arrow below the paragraph connects the text "MDC" to "queue override" in the paragraph above.)

Slide 58:

Learning Objective #3--

Finding User Needs from Annex A and Applying Writing Criteria (cont.)

(Extended Text Description: In this slide, there is a text box that contains the following text: UN 2.6 Traffic Responsive - The agency needs to implement a traffic responsive metering mode based on the plan selection that includes metering rate and metering levels based on occupancy thresholds to respond to change in traffic conditions as reported by the mainline and ramp detectors.

A curved arrow below the paragraph connects the text "Unique ID" to "UN 2.6 Traffic Responsive" in the paragraph above. A curved arrow below the paragraph connects the text "Rationale" to "thresholds to respond" in the paragraph above. A curved arrow below the paragraph connects the text "Solution-free" to "conditions as reported" in the paragraph above. A curved arrow below the paragraph connects the text "MDC" to "a traffic responsive metering mode" in the paragraph above.)

Slide 59:

Learning Objective #3

Deriving User Needs from the State Diagram

(page 8)

(Extended Text Description: Author's relevant notes: Deriving User Needs from the State Diagram (page 8): This page is taken from the Standard, which show various transition states of the RMC. On the right, a signal head is shown with RED, YELLOW, GREEN. Key Message: This state diagram shows how transition should take place from NON-Metering State to Metering State. User need not be concerned at user needs level, but it does offer a link to potential user needs. The diagram is included in this presentation primarily as information, as A sections are linked. (Note: v01 did present this diagram but did not include A sections links). We can still derive user needs without this diagram. Source: NTCIP 1207 v02.)

Slide 60:

Learning Objective #3

Deriving User Needs from State Diagram and Applying Writing Criteria

(Extended Text Description: In this slide, there is a text box that contains the following text: UN 2.7 Signal Service - The agency needs to adhere to transitioning from a non-metering state to a metering state within the intervals of alert, warning, green-yellow-red intervals, and during a non-metering state control of an advanced warning sign.

A curved arrow below the paragraph connects the text "Unique ID" to "UN 2.7 Signal Service" in the paragraph above. A curved arrow below the paragraph connects the text "Rationale" to "state control" in the paragraph above. A curved arrow below the paragraph connects the text "Solution-free" to "advanced warning sign" in the paragraph above. A curved arrow below the paragraph connects the text "MDC" to "transitioning" in the paragraph above.)

Slide 61:

Learning Objective #3

Deriving User Needs from State Diagram and Applying Writing Criteria (cont.)

(Extended Text Description: In this slide, there is a text box that contains the following text: UN ID 2.8 Transitioning - During a non-metering state, the RMC unit ceases all metering and signalized control. Advanced warning signs and all signal lamps are to be dark while in this state. This mode is implemented at the end of a metering cycle green interval. Detector monitoring continues without interruption in processing while the controller is in the non-metering state.

A curved arrow below the paragraph connects the text "Unique ID" to "UN ID 2.8 Transitioning" in the paragraph above. A curved arrow below the paragraph connects the text "Rationale" to "end of a metering cycle" in the paragraph above. A curved arrow below the paragraph connects the text "Solution-free" to "interruption in processing" in the paragraph above. A curved arrow below the paragraph connects the text "MDC" to "ceases all metering" in the paragraph above.)

Slide 62:

Learning Objective #3

Finding User Needs from the Conformance Groups (Annex B)

A CG is a Grouping of Related Objects that Supports a User Need(s)

B.3	General Configuration	Basic Set Up of the Device
B.4	Traffic Responsive	Implement Metering Plan
B.5	Metered Lane-Demand Detector	Metering Operation (Action)
B.6	Dependency Group	Relationship to other Lanes
B.7	Queue Detection	Measure Ramp Volume
B.8	Passage Detection	Checkout-Vehicle has Passed
B.9	Time Base	Global Scheduling
B.10	Physical I/O	Assignments-Sign Control
B.11	Block Object	String of Objects to Move Data

Slide 63:

Learning Objective #3

Content of (B.5) Metered Lane Conformance

Group (page 189)

This CG is Mandatory and Generates Minimum Set of User Needs

• Functions (actions) performed (as requested by a command source):
  • Fixed rate
  • Traffic responsive
  • Dark
  • Rest-in-green, rest-in-red
  • Emergency green
  • Vehicle per green
• Demand detection

(Extended Text Description: Author's relevant notes: Content of (B.5) Metered Lane Conformance Group (page 189): A photo of an RMC unit from Caltrans is shown on the right side of this slide.)

Slide 64:

Learning Objective #3

How to Apply a Generic Process for Extracting MDC from a CG

(Extended Text Description: Author's relevant notes: How to Apply a Generic Process for Extracting MDC from a CG: Three text boxes are used on this and the next slide. The first READ box feeds into RECOGNIZE box with an arrow; and then another arrow feeds into the last box, INFER MDC. Key Message: This slide reminds the participant about the extraction process introduced in Module A202 and shows three steps: READ, RECOGNIZE, and INFER a MDC. As shown in the slide, READ step will cover four CGs and MIB objects listed in the standard, followed by the RECOGNIZE step, which points to which functions are covered by both. Final INFER step is to infer MDC contained in a function or functions. A user need writing process then begins based on an MDC.)

Slide 65:

Learning Objective #3

Example: Applying a Generic Process

(Extended Text Description: Author's relevant notes: Example: Applying a Generic Process: Same as above graphic (on slide 65). Arrangement used for Traffic Responsive CG. Key Message: The slide shows how to apply a generic process to extract a user need. It begins with a reading of a CG followed by a related clause of a pertinent objects, which in turn leads to a MDC. With these three steps, the example shows how to derive a MDC.)

Slide 66:

Learning Objective #3

Extracting MDCs from Multiple CGs

(Extended Text Description: Author's relevant notes: Extracting MDCs from Multiple CGs: Two one-way arrows are shown from a text box going from Traffic Responsive Plan to B.3 CG and to B.4 CG. From B.3, two arrows go to Object 1 and Object 2. This shows that multiple CGs are used. Similarly, B.4 CG has three arrows going into three separate objects.)

These two CGs offer several objects that will be examined for extracting MDCs to develop the user need.

Slide 67:

Learning Objective #3

Example: Applying User Needs Writing Criteria

(Extended Text Description: In this slide, there is a text box that contains the following text: UN 2.9: Configure a RMC Unit - A TMC operator, with access to a management station, has a need to retrieve information about the configuration of the RMC unit to properly communicate with the device. The controlling entity may also need to alter the configuration to produce expected operations.

A curved arrow below the paragraph connects the text "Unique ID" to "UN 2.9: Configure a RMC Unit" in the paragraph above. A curved arrow below the paragraph connects the text "Rationale" to "produce" in the paragraph above. A curved arrow below the paragraph connects the text "Solution-free" to "operations" in the paragraph above. A curved arrow below the paragraph connects the text "MDC" to "retrieve information" in the paragraph above.)

Slide 68:

Learning Objective #3

Example: Applying User Needs Writing Criteria

(Extended Text Description: In this slide, there is a text box that contains the following text: UN 2.10: Command Source Priority - The TMC operator, with access to the RMC system, has a need to allow for five priority-based mechanisms to control the RMC unit to take metering action(s). The sources desired in priority order are: manual (local at front panel), communications from a central location (TMC), interconnect (from peer to peer communications from a filed master controller), time base control (TBC for special events) and default. Default mode is placed in effect after skipping all other commands due to loss failures.

A curved arrow below the paragraph connects the text "Unique ID" to "UN 2.10: Command Source Priority" in the paragraph above. A curved arrow below the paragraph connects the text "Rationale" to "to control" in the paragraph above. A curved arrow below the paragraph connects the text "Solution-free" to "communications" in the paragraph above. A curved arrow below the paragraph connects the text "MDC" to "five priority based" in the paragraph above.)

Slide 69:

Learning Objective #3

Example: Applying User Needs Writing Criteria (cont.)

(Extended Text Description: In this slide, there is a text box that contains the following text: UN 2.11: Command Source Parameters - Each metering command source has four parameters to complete metering functions: Action, metering rate, metering plan, and vehicle per green.

A curved arrow below the paragraph connects the text "ID" to "UN 2.11: Command Source Parameters" in the paragraph above. A curved arrow below the paragraph connects the text "Rationale" to "complete" in the paragraph above. A curved arrow below the paragraph connects the text "Solution-free" to "vehicle per green" in the paragraph above. A curved arrow below the paragraph connects the text "MDC" to "metering rate" in the paragraph above.)

Slide 70:

Learning Objective #3

User Needs Translates to RMC Unit "Actions"

(Extended Text Description: Author's relevant notes: User Needs Translates to RMC unit "Actions": A photo of the TMC is shown on the left side of the slide. The RMC unit photo is in the middle and a text box that lists the action is on the right. A short arrow also appears from the text below the TMC and goes to the text below the RMC unit, which reads, "Functional Requirements." Key Message: This layout prepares students for understanding how RMC action is achieved: a user need is shown from an operator perspective which becomes a requirement that drives a functionality-capacity RMC must provide in the form of an action. A TMC operator needs to make a request to the RMC unit (FUNCTION) to implement any of the actions listed in the last box. In a typical operation, TMC software will either invoke fixed rate metering or traffic responsive based on time of day or other policy criteria. Other actions are also taken when needed basis.)

Slide 71:

Learning Objective #3

Writing a User Need for the RMC Unit Action

(Extended Text Description: In this slide, there is a text box that contains the following text: UN 2.12: Metering Action - The RMC unit performs five metering operations that includes: Dark, rest-in-green, fixed rate metering, traffic responsive metering, emergency green. The primary metering focus of the agency is to implement a fixed rate metering to manage recurring congestion.

A curved arrow below the paragraph connects the text "Unique ID" to "UN 2.12: Metering Action" in the paragraph above. A curved arrow below the paragraph connects the text "Rationale" to "manage recurring" in the paragraph above. A curved arrow below the paragraph connects the text "Solution-free" to "congestion" in the paragraph above. A curved arrow below the paragraph connects the text "MDC" to "five metering" in the paragraph above.)

Slide 72:

Learning Objective #3

Summary of RMC User Needs Examples

Note: Titles of local user needs may change somewhat during specification preparation.

• UN 2.1 Provide Live Data Exchange
• UN 2.2 Provide Logged Data Exchange
• UN 2.3 Provide Capability to Retrieve RMC Identity
• UN 2.4 Fixed Rate
• UN 2.5 Queue Override
• UN 2.7 Signal Service
• UN 2.8 Transitioning
• UN 2.9 Configure a RMC Unit
• UN 2.10 Command Source Priority
• UN 2.11 Command Source Parameters
• UN 2.12 Metering Action

Slide 73:

Learning Objective #3

What to Do If Certain User Needs Are Not Met by the RMC Standard

• If an agency has a situation that translates to an unmet user need, consider the following:
  • Establish whether any non-standard capabilities are really needed
  • Are you expanding metering to other local ramp corridors using the same central control software?
  • Consider cost implications of extended features: specification, testing, and maintenance of a proprietary solution
• If a proprietary-custom solution is warranted due to additional needed functionality, the user needs driving the solution should be documented in the ConOps

Slide 74:

Slide 75:

Learning Objective #3

What is the best source of user needs?

Answer Choices

1. Freeway Traffic Management Concept of Operations (ConOps)
2. Regional ITS Architecture Ramp Metering Service Package
3. NTCIP 1207 v02 Standard Documentation
4. All of the above sources

Slide 76:

Learning Objective #3

Review of Answers

a) Freeway Traffic Management Concept of Operations
Incorrect. Exploring the ConOps is an important source but is only partially true.

b) Regional ITS Architecture Ramp Metering Service Package
Incorrect. Architecture is framework-only and is a partial source at best.

c) NTCIP 1207 v02 Standard Documentation
Incorrect. The standard offers design solutions—CGs and operational description, but it is not sufficient from users' operational needs perspective, which emerges from ConOps.

d) All of the above sources
Correct! All of the above sources have links to user needs. Assessment of each will ensure our purpose to identify user needs.

Slide 77:

Summary of Learning Objective #3

Prepare Well-Written User Needs for RMC Units

• We have realized that RMC user needs are not available and we must develop them for the acquisition process
• Discussed how to extract user needs and write them for procurement using a criteria
• Discussed what to do if certain user needs are not met by the standard

Slide 78:

Learning Objective #4: Explain How to Evaluate Conformance to the RMC Standard

• What are the minimum conformance requirements?
• Explain how to address backward compatibility issues

Slide 79:

Learning Objective #4

What are the Minimum Conformance Requirements?

• RMC Unit Standard Conformance Group (CG) Table Sates Requirements as:
  • Mandatory (M) CGs are very basic types and are required for conformance to the NTCIP 1207 v02 Standard (also include the Configuration CG from the NTCIP 1201 v02 Global Standard, which is required for conformance)
  • Optional (O) CGs are selected by the agency specification to meet local user needs

Slide 80:

Learning Objective #4

(Extended Text Description: Author's relevant notes: RMC Unit CG Table Mandatory CG: An arrow from the text box on top points to an M located in the second column, marked as the status for Metered Lane CG. Another arrow points to M for Configuration CG. The arrows point to Mandatory CGs that must be selected YES in the last column marked as support. Key message: Annex B lists a CG Table, each column is explained and stress that M-Mandatory is minimum required. The data in the table is as follows:

Ref	Areas	Clause of Profile	Status	Support
B.3	General Configuration Conformance Group	NTCIP 1207-3.2	O	Yes/No
B.4	Traffic Responsive Conformance Group	NTCIP 1207-3.3	O	Yes/No
B.5	Metered Lane Conformance Group	NTCIP 1207-3.3	M	Yes
B.6	Dependency Group Conformance Group	NTCIP 1207-3.4	O	Yes/No
B.7	Queue Detection Conformance Group	NTCIP 1207-3.4	O	Yes/No
	- Length Based Queue Detection		O	Yes/No
	- Occupancy Based Queue Detection		O	Yes/No
	- Quick Occupancy Based Queue Detection		O	Yes/No
	- Rate Adjusted Queue Adjustment		O	Yes/No
	- Level Adjusted Queue Adjustment		O	Yes/No
	- Fixed Rate Queue Adjustment		O	Yes/No
B.8	Passage Detection Conformance Group	NTCIP 1207-3.5	O	Yes/No
	- Long Stop	NTCIP 1207-3.5	O	Yes/No
B.9	Time Base Conformance Group	NTCIP 1207-3.6	O	Yes/No
	- Mainline Scheduling	NTCIP 1207-3.6	O	Yes/No
B.10	Physical I/O Conformance Group	NTCIP 1207-3.7	O	Yes/No
	- Metered Lane Output	NTCIP 1207-3.7	O	Yes/No
	- Dependency Group Output	NTCIP 1207-3.7	O	Yes/No
B.11	Block Object Conformance Group	NTCIP 1207-3.8	O	Yes/No
B.12	Configuration Conformance Group	NTCIP 1201 -2.2	M	Yes

)

Slide 81:

Learning Objective #4

Example of Mandatory CG

(Extended Text Description: Author's relevant notes: Example of Mandatory CG: One arrow from top YES goes to last column marked YES and one arrow from CONFORMANCE at bottom goes to B.5 Metered Lane at top. Key message: This slide points out that  this CG is Mandatory for conformance, and user must select YES. The data in the table is as follows:

B.5

Metered Lane Conformance Group

NTCIP 1207 -3.3

M

Yes

The implementation text is as follows:

Metered Lane
Metered Lane Main
rmcMaxNumMeteredLanes
rmcNumMeteredLanes
rmcMeterCfgTable
  rmcMeterCfgEntry
  rmcMeterNumber
  rmcCmdSourcePriorityOrder
    schemeCIT (1),
    schemeICT (2),
    schemeTCI (3),
    schemeTIC (4),
    schemeCTI (5),
    schemeITC (6)

)

Slide 82:

Learning Objective #4

Example of Optional CG

(Extended Text Description: Author's relevant notes: Example of Mandatory CG: One arrow from top YES goes to last column marked Yes and one arrow from compliance at bottom goes to B.4 Traffic Responsive Conformance Group. Key message: This slide points out that NTCIP 1205 does have a set of conformance requirements. User needs must map to these conditions. The data in the table is as follows:

B.4

Traffic Responsive Conformance Group

NTCIP 1207 -3.3

0

Yes / No

The implementation text is as follows:

Metering Plan

rmcMaxNumMeteringPlans
rmcNumMeteringPlans
rmcMaxNumLevelsPerPlan
rmcNumMeteringLevels
rmcMeteringPlanTable
  rmcMeteringPlanEntry
  rmcMeteringPlanNumber
  rmcMeteringLevel
  rmcMeteringRate
  rmcFlowRateThreshold
  rmcOccupancyThreshold
  rmcSpeedThreshold

)

Slide 83:

Learning Objective #4

Traceability with Conformance Groups

Identified RMC user needs can ONLY be traced to the CGs in this standard.

(Extended Text Description: Author's relevant notes: Key Message: This slide shows how a UN can be traced to CGs. CGs also lead us to objects for the specification. The data in the table is as follows:

User Need	Conformance Group	Requirement	Object Support
UN 1 Configure RMC Unit	B.3 General Configuration
	B.5 Meter Lane
UNs	B.4 Traffic Responsive

Note there is a red arrow pointing from B.3 General Configuration to UN 1 Configure RMC Unit.)

NOTE: We will learn more on handling traceability in the next module, A309b.

Slide 84:

Learning Objective #4

Interoperability

• Interoperability issues:
  • RMC units are remotely accessed and may be controlled by management stations located at the TMC or other operation centers
  • To achieve interoperability, agencies must select the same user needs and design solutions, and must use common protocols (compatibility)
  • Ramp metering is a component of a freeway management system and may be shared by multiple agencies; use of common C2C Standards may be needed

Slide 85:

Learning Objective #4

Addressing Backward Compatibility

• NTCIP 1207 v02 is backwards compatible with NTCIP 1207 v01 and standard text advises readers where changes have been made:
  • Some objects have a 1-255 value range instead of a 0-255 range
  • Dialogs (a mechanism to communicate messages with the device) have NOT been defined in RMC; consistency may be an issue
  • Although technically RMC can mix ATC and 2070-170 in the same corridor, local interface constraints may remain; a check may be needed on firmware

Slide 86:

Slide 87:

Learning Objective #4

Which of the following is a FALSE statement related to the NTCIP 1207 RMC v02 Standard?

Answer Choices

1. Only Metered Lane CG is required to conform to the standard
2. Traffic Responsive CG is optional
3. V02 Standard is NOT compatible with the previous version
4. A CG represents one or more RMC unit function

Slide 88:

Learning Objective #4

Review of Answers

a) Only Metered Lane CG is required to conform to the standard
Incorrect. The statement is true. It is a mandatory CG.

b) Traffic Responsive CG is optional
Incorrect. The statement is true. It is required only when an agency desires to implement metering based on real-time traffic data.

c) v02 Standard is NOT compatible with the previous version
Correct! The statement is FALSE. V02 is compatible with the previous version.

d) A CG represents one or more RMC unit function
Incorrect. A CG is a grouping of objects that represent a function.

Slide 89:

Summary of Learning Objective #4

Explain How to Evaluate Conformance to the RMC Standard

• We have reviewed the RMC Standard conformance requirements as stipulated in Table B.2, including mandatory CGs
• We also reviewed interoperability and backwards compatibility issues

Slide 90:

What We Have Learned

1. NTCIP 1207 v02 Non-SEP Standard does not have user needs, and we must identify and write them using a criteria.
2. RMC unit user needs can be found in ConOps ,conformance groups and operation descriptions .
3. A user need must be uniquely identifiable , and defines major desired capability , provides a rationale and is solution-free.

Slide 91:

What We Have Learned (cont.)

1. Types of metering include fixedrate metering, traffic responsive and corridor-wide metering adaptive
2. Highest priory command source in RMC is manual , followed by communications.
3. All mandatory CGs must be included in the specification for conformance to the standard.

Slide 92:

Next Course Module

A309b:

Understanding Requirements for Ramp Meter Control (RMC) Units Based on NTCIP 1207 v02 Standard

Slide 93:

Resources

• NTCIP Standards available at www.ntcip.org:
• NTCIP 1201 v03 Global Object Definitions
• NTCIP 1207 v02 Ramp Meter Control (RMC) Units
• NTCIP 9001: Information report Guide available at www.ntcip.org
• A202: Identifying and Writing User Needs When ITS Standards Do Not Have SEP Content (stds_training.aspx)
• Participant Student Supplement
• Overview of RMC Practice
• List of RMC User Needs
• References on Ramp Metering Practice
• Kansas City SCOUT-Video on Ramp Metering (4 min.)

http://www.kcscout.net

Slide 94: