1

Transit Signal Prioritization (TSP)Considerations within RTS Corridors

Rapid Transit System Steering Committee

Technical Memorandum 2 Existing Conditions Signal Systems & Corridor Operations

December 17th, 2013

2

Key Findings• 10 Route RTS network has 116 stations overlaying 284 existing

traffic signals and 820 existing bus stops• Implementing advanced TSP within RTS requires close

coordination of existing agencies and systems. Cannot be done in isolation.

• Existing signal controllers/ central software currently does not support all advanced TSP functions

• Would require time and cost to upgrade, cost TBD• Primary traffic control system function is to monitor signal

performance for roadway safety and mobility• TSP is a secondary function within overall operations• Incorporating WMATA buses into RTS would require additional

hardware and software, cost TBD• Council resolution shifts TSP decisions based on ROW

treatment to Facility Planning stage

Priority Transit Corridors and Montgomery County Signals

Countywide Transit Corridors Functional Master Plan Planning Board Draft (MNCPPC, July 2013)

Summary Table

From To

Stati

ons

(RTS

& M

etro

)

Sign

als

Sign

als w

ith V

/C >

0.

95

Bus S

tops

Leng

th (M

iles)

Mix

ed F

low

Mix

ed F

low

w Q

ueue

Jum

p

Dedi

cate

d Cu

rb La

nes

Man

aged

Lane

(d

edica

ted

1 w

ay P

k)

1 La

ne M

edan

Bu

sway

(bi-d

ir)

1 La

ne M

edia

n Bu

sway

(1 w

ay)

2 La

ne S

ide

Busw

ay (2

way

)

2 La

ne M

edia

n Bu

sway

(2 w

ay)

2 La

ne N

ew R

OW

Bu

sway

(2 w

ay)

1 Georgia Avenue North

Montgomery General Hospital

Wheaton Metrorail station

13 30 5 114 9.6 1.0 8.6

2 Georgia Avenue South

Wheaton Metrorail Station

District of Columbia line

8 24 3 48 3.9 2.2 1.7

3 MD 355 NorthCorridor Cities Transitway

Rockville Metrorail station

20 37 23 120 14.1 3.5 10.6

4 MD 355 SouthRockville Metrorail Station

District of Columbia line

14 47 22 106 9.3 0.0 1.2 8.2

5 New Hampshire Avenue

Colesville Park & Ride

District of Columbia line

12 34 4 89 8.5 2.8 3.8 1.8

6 North Bethesda Transitway

White Flint Metrorail Station

Montgomery Mall Transit Center

7 14 1 23 2.7 0.3 1.5 0.9

7 Randolph Road US 29White Flint Metrorail Station

11 30 7 105 10.1 10.1

8 University Boulevard

Wheaton Metrorail Station

Takoma/Langley Transit Center

9 21 5 76 5.5 2.7 2.8

9 US 29Burtonsville Park & Ride

District of Columbia line

11 22 7 70 11.0 3.4 1.1 0.9 5.6

10 Veirs Mill RoadRockville Metrorail Station

Wheaton Metrorail Station

11 18 5 69 6.2 6.2

Totals 116 277 82 820 81.0 25.9 0.0 4.0 0.9 6.2 16.8 0.9 26.2 0.0

Miles

Corridor

MNCPPC Funtional Master Plan Planning Board Draft

Traffic Signals in Montgomery County by Ownership/Operation & Potential TSP Corridors

Traffic Signals in Montgomery County by Ownership & Operation

• 63% Owned by the State of Maryland• 31% Owned by Montgomery County• 5% Owned by the City of Rockville• 91% Operated by Montgomery County• Approximately 30 of the MDSHA signals in and around Takoma Park & New

Hampshire are not operated by the County– 10 will migrate to County operations in the near future– 15 are along New Hampshire Avenue (4 outside the County)

• Majority of the Signals along the RTS routes are owned by MDSHA

County MDSHA Rockville TotalCounty 274 0 0 274 31%MDSHA 522 29 6 557 63%Rockville 6 0 42 48 5%Total 802 29 48 879 100%

91% 3% 5% 100%

OperatesO

wns

Montgomery County Advanced Transportation Management System (ATMS)

• Traffic signal operations key component of ATMS• Traffic Signal System Modernization Completed in 2012

– New computer and servers– Custom traffic operations and ATMS Software– Upgrade of all MDSHA and County traffic signal controllers to

modern Econolite ASC/3 controllers– High speed communications network for real time operations– Distributed signal control system (using the ASC/3 controllers)

• Each ASC/3 controller is TSP ready (with $400 TSP data key)• Developed/tested recommended TSP Architecture:

– Econolite ASC/3 controllers– GTT Opticom GPS Spread Spectrum TSP system– ORBCAD Transit Automated Vehicle Location/Computer Aided

Dispatch

8

ATMS Operations Center

Montgomery County Recommended TSP Architecture

ASC/3 Signal Controller

Traffic SIGNAL

Transit Management

Traffic Management

GPS

Priority Request

Generator

Vehicle Tracking & Detection

1

2 Priority Request Server

3

4

Monitoring and logging data

AVL

& C

ompu

ter A

ided

Dis

patc

h

I Am HERE

I Want Priority

Vehicle is in rangeWho gets PrioritySignal Strategy to use

Adjusted phasesIn cycle

ATMS Central OperationsSoftware

ORBCAD CentralSoftware

ORBCAD Veh. Components:

I am LateGTT Opticom

GPS TSP System

Recommended Countywide TSP Concept of Operations

• Assumes Current Service– Transit vehicles in mixed flow without other priority

measures– No differentiation between types of transit service

• TSP Request when bus is more than 5 minutes late• TSP Granted on first come first served basis• TSP Signal Strategies

– Green Extension– Early Green

• Signal coordination allowed to “recover” between instances of signal priority – 3 cycles between granting requests)

Issues of Concern to RTS from Current Systems Review (1)

• Current Montgomery County System can implement:– Early green,– Extended green – Leading green for queue jumps

• Other TSP Signal Strategies will be costly and require changes to the overall system (beyond firmware v 2.50)

• GTT Opticom GPS TSP System– Recommended for Montgomery County and WMATA – WMATA's recommended system uses different

communications. – WMATA System in Montgomery County

• Need cellular modems at the roadside (cabinet) for each signal location • Tests to make sure inputs from Ride On and WMATA can work together

Issues of Concern to RTS from Current Systems Review (2)

• Automatic Vehicle Location/Computer Aided Dispatch– Ride On ORBCAD AVL/CAD system tested for TSP in Montgomery

County– Not Used by WMATA (Clever Devices) – AVL/CAD for RTS needs to be determined.

• City of Rockville – No signals operated by Rockville directly on the RTS corridors – Two signals on CCT right of way – Potential for TSP at Rockville signals with diversions to reach special

destinations (e.g. Community College) – Any integration with the Rockville system will require upgrades to its

controllers and/or central software.

• Integrating Current MTA Commuter Service (provided by contractors with no AVL/CAD) requires added technology

• RTS will need to integrate/coordinate with CCT and Purple line.

RTS ROW Priority Treatments versus TSP Signal Operations

ROW Treatments Passive Extend Green Red Truncate Insert Transit

PhasePhase Rotation

/SwapPhase

Suppression

Non-RTS Corridor ~ 595 Mixed Flow 84 Mixed Flow w Queue Jump 0 Transit only

Early Green

Dedicated Curb Lanes 19 Managed Lane (dedicated 1 way Pk) 4 1 Lane Medan Busway (bi-dir) 18 1 Lane Median Busway (1 way) 57

2 Lane Side Busway (2 way) 4 2 Lane Median Busway (2 way) 98 LRT ROW (Purple Line) ~14

Potential Signal Treatments*CurrentSignals

* Insert Transit Phase, Phase Rotation, & Phase Suppression would require upgrade of Signal System Software

Other Characteristics impacting TSP (Turns, Other Service)

ROW Treatments Right Left LRT RTS Express LocalNon-RTS Corridor Y Y Y N Y YMixed Flow Y Y Y Y Y YMixed Flow w Queue Jump Y Y Right Trn Y Y YDedicated Curb Lanes Fac Plng Y Right Trn* Y Y YManaged Lane (dedicated 1 way Pk) Fac Plng Y Right Trn* Y Y Y1 Lane Medan Busway (bi-dir) Fac Plng Fac Plng N Y Fac Plng N1 Lane Median Busway (1 way) Y Fac Plng N Y Fac Plng N2 Lane Side Busway (2 way) Y Y N Y Fac Plng N2 Lane Median Busway (2 way) Y N N Y Fac Plng NLRT ROW (Purple Line) Fac Plng Fac Plng N Y Fac Plng N N

* If permitted

Turns Permitted Traffic Lane Use

Transit Service in Priority ROW

Factors influencing TSP Strategiesat Specific Intersections

• Roadway:– Intersection Level of Service– Available green time (slack) – Cross street facility type – Bicycle & Pedestrian treatments and priority areas,

• Transit:– Other Transit Service in the Corridor– Cross street transit service– Bus stop/station locations – Service frequency – Time between priority requests– Ridership

Overall System and Policy Decisions Needed• Can’t determine TSP at specific intersections until facility

planning for each corridor• Can/Should decide:

– Integrated or separate • Operations centers• Communications• TSP systems and equipment

– TSP Architecture (centralized, distributed, communications, etc.)– Recommended TSP by ROW Priority Treatment

• Types of transit service receiving TSP in corridor• Decision strategy for enabling TSP and each intersection• Conditional parameters (direction, time of day, schedule, passengers,

frequency of granting requests)• Types of TSP signal strategies to provide for

– RTS and Purple Line integration

Technical Memorandum 3,RTS & TSP Findings & Recommendations:

• What do we have today, what do we want to have in the future?

• Cost to deploy all add-on TSP configurations within the current signal system

• Concept of operations – defined scenarios with– RTS vehicles only– RTS and other transit providers in RTS ROW– RTS and conflicting local transit outside RTS ROW– RTS and conflicting LRV outside RTS ROW

• What needs to happen for each type of strategy/ ROW– Technology, agency agreements, etc.

Back up Slides

Econolite ASC/3 Controller• Controls signal phasing, TSP

strategy length of priority, lock out periods (16 phases max)

• Current advanced controller offered by Econonlite• Compatible with Standards (NEMA TS2, NTCIP 2011)• 1 TSP request addressed per cycle (check in/out or continuous monitoring)• TSP ready (with $400 TSP data key)• TSP Strategies with current firmware (v 2.45, planned 2.49)

– Extended green– Early green– Leading green for queue jump

• Additional features/strategies dependent on firmware v 2.50 and above

• Firmware v 2.50 and above incompatible with ATMS Central Operations Software. Very costly to upgrade

GTT Opticom GPS TSP System

• Recommended forMontgomery County existing system

• Also selected by WMATA (with differences) and MDSHA in other areas (for preemption). On MDSHA procurement schedule.

• Components/functions– On-vehicle (PRG: sends request when criteria are met)– Wayside antennae (spread spectrum) to receive vehicle location– Phase selector (PRS: validate position, in range ?, prioritize/resolve conflicts,

send request to controller)

• Additional central software to provide monitoring and logging data also recommended

• Proved technically feasible in Route 55 MD 355 TSP test• How to integrate across operating agencies / services

remains to be seen

ORBCAD AVL/CAD System• Automatic Vehicle Location and Computer Aided

Dispatch system implemented by Ride On• Currently provided by ACS Systems/Xerox (has gone

through several transitions)• Functions

– Real time vehicle location and monitoring– Schedule and route adherence– Data and voice communications (mobile data terminal)– Voice annunciation for stops along routes– Silent alarm– Automatic Passenger Counts– TSP integration to identify late vehicles, passengers, etc.

• Integration with TSP proven technically feasible in Route 55/MD 355 TSP test.

City of Rockville Signal System• 143 signals within or near

Rockville Boarders• City owns 48 signals• City operates:

– 42 of its own signals– 6 of the MDSHA signals

• Econolite ASC/2 Controllers with limited TSP capability

• Aires Closed Loop traffic system with dial up connection (not real time)

• No City Signals directly on RTS Routes

• 2 City Signals on the CCT corridor

Ride On Montgomery County Transit (Ride On)• Weekday service:

– 78 routes– 289 peak vehicles

• Provides service in every proposed RTS corridor• Operations colocated with traffic but not integrated• Trapeze bus scheduling and run-cutting software• Smart Traveler Customer Information • Regional Smart Card Fare Payment• Implementing Automatic Passenger Counters (~ 55%)• ORBCAD Avl/Cad system

– Will allow Conditional TSP on Schedule Adherence and Passenger Loads

• Only Route 55 TSP vehicles for TSP Test equipped with GTT Opticom GPS TSP systems

Washington Metropolitan Area Transportation Authority (WMATA)

From: A. Young Leveraging the WMATA CoABE Project Technology for TSP Implementation (ITS Maryland, October 2013)

• Consolidated onboard & fixed end equipment in 2012/2013

• Clever Devices AVL/CAD

• GTT Opticom TSP software/hardware

• Cellular communications with the Intelligent Vehicle Network (IVN) Unit

• Roadside (cabinet) cellular modem with GPS• Econolite ASC3 controller through GTT Phase Selector

Washington Metropolitan Area Transportation Authority (WMATA)

• Service– 140 Metrobuses in peak periods within Montgomery County– Primarily regional service along major corridors– WMATA service in every proposed RTS corridor

• Issues– Installation, recurring costs, maintenance of cellular modems

within Montgomery County signal cabinets– Reconciliation/integration between WMATA Cellular and

Montgomery County Spread Spectrum vehicle to roadside communication (can inputs be received and integrate from both)

– Resolving competing priority requests between Montgomery County and WMATA vehicles

– Communication/coordination between operation centers

Maryland Transit Administration (MTA)• Current Service

– Route 201 Gaithersburg to BWI Marshall Airport– Route 202 Metropolitan Grove to DOD/Ft. Meade– Route 203 Columbia to Bethesda– Route 204 Frederick to College Park– Route 915 Columbia/Silver Spring to Washington, DC– Route 929 Columbia/Silver Spring to Washington, DC– Route 991 Hagerstown/Frederick to Shady Grove/Rock Spring

Business Park– Route 995 Clarksville/Ellicott City/Columbia to Washington, DC

• Contract Service with no AVL/CAD or other technology requirements

• Future Systems (will need to coordinate)– Purple Line– Corridor Cities Transitway (CCT)