Multimodal Approach to Planning & Implementation of Transit Signal Priority within Montgomery County Maryland

Transcription

1 Multimodal Approach to Planning & Implementation of Transit Signal Priority within Montgomery County Maryland A Path to Successful Implementation James Allday Bunch - Sabra, Wang & Associates, Inc. ITE 2014 Hershey, PA 1

2 Outline Overview of Transit Signal Priority Implementing TSP within Montgomery Co. Countywide Transit Signal Priority Transit Signal Priority within RTS Policy Questions 2

3 What is Transit Signal Priority (TSP) TSP is a traffic signal operational strategy that facilitates the movement of transit vehicles, either buses or streetcars, through traffic signal controlled intersections. Passive TSP adjusts signal timing/coordination for transit operations Active TSP is used to provide passage for transit vehicles at signalized intersections when requested. Conditional TSP requests priority only if certain conditions are met. TSP (active, conditional priority) should NOT to be confused with Emergency Vehicle Preemption which is unconditional priority Source: TSP Handbook 3

4 Transit Signal Priority Strategies Green Extension Red Truncation Transit Only Phase Queue Jump (early green) Diagonal Crossing (all red) Phase rotation/swapping Phase suppression/skipping

5 Benefits of TSP Improve travel time reliability and schedule, reduce delay and reduce emissions, may increase ridership Waiting at Traffic Signals represents an average of 15% of a bus s trip time 1. Cause of signal delay include: Pedestrians Crossing Volume-related delay Accommodating side-street traffic Special phases (e.g. left-turns only). Conditional Priority reduces severe delay and improves reliability 1. ( Overview of Transit Signal Priority. ITS America, 2004) 5

6 What Happens to TSP with Competing Demands at the Intersection? High Vehicular demand High Transit Demand High Pedestrian Demand Emergency Vehicle Pre-Emption Can I have more time to cross the street? Can everyone stop for me for a few minutes? I am behind schedule can I have some extra green? Will I have enough green time to clear the intersection? I need a longer green arrow for this left-turn I am behind schedule can I have some extra green? 6

7 General TSP Questions/Issues Does the intersection cause significant signal delay to transit vehicles? Is there significant variability in the delay that transit vehicles experience that is greater than expected due to signal timing? Are transit vehicles caught in upstream queues and other congestion? Can transit vehicles avoid upstream queues and other congestion? Are there potential conflicts with other transit service when priority is granted (other main, or cross)? Are there physical constraints? Will there be significant impacts to the signal phasing (is there available green, etc.)? Will the person time savings and throughput increase (on main lines, on cross streets)?

8 Potential Tradeoffs & Factors Transit Service & TSP Countywide TSP Mixed Flow Transit Local Express TSP Green Extension Red Truncation BRT & TSP Mixed Flow - 2 way exclusive Transit BRT Local Express TSP Passive Green Ext Red Truncation Transit Only Phase rotation/ swapping Phase skipping LRT & TSP Fixed tracks (mixed & Exc.) Transit LRT BRT Local Express TSP Preemption? Passive Green Ext Red Truncation Transit Only Phase rotation/ swapping Phase skipping Transit Priority Treatments

9 Countywide TSP Study Phase I State of the Practice/ Lessons Learned Infrastructure and Communications System Readiness Phase II Needs Assessment Phase III Concept of Operations Development Technology Assessment and Selection Data Requirement Procurement and Deployment Pilot Study Demonstration and Evaluation Identify, Screen and Select Routes and Performance Metrics Develop TSP Policy: Warrants and Conditional Measures Coordinate with agency Stakeholders Deployment Recommendations 9

10 Countywide TSP Signal Priority Options In conjunction with no other transit priority treatments Extend Green Phase Truncate Red Phase Build upon Traffic Signal System Modernization (TSSM) project and ATMS transit CAD/AVL upgrades & Technology Assessment Econolite ASC/3 traffic signal controller with TSP Distributed TSP Architecture GTT Opticom GPS system for TSP

11 Corridor / Segment Countywide TSP Three Level Screening Which bus routes and vehicles should be TSP enabled? Intersection Which intersections should provide for TSP? Trip (Conditional TSP) TSP provided when conditions are met: Time of Day Vehicle running late Does not cause undo impact on traffic system operations

12 18 corridors initially identified Over 800 traffic signals maintained by the County Over 350 signals in the selected 18 corridors 12

13 TSP Corridor Ranking Maximize benefits to transit operations with the least impact on traffic flow. Transit Measures Bus routes (busses) Average PM peak hour bus speeds Productivity (Riders per vehicle mile) Traffic Characteristics AADT, Signal density Number of arterial cross streets Number of intersections with failing LOS Traffic signal cycle lengths Pedestrian volumes Average PM peak travel speeds. High Rank: Georgia (MD 97) North, Colesville Rd (US 29) Low Rank: Muddy Branch Rd, Quince Orchard Rd (MD 124)

14 TSP Intersection Selection Flow Chart Does the intersection fall within a selected study corridor? NO Is TSP Feasible at Intersection? YES 0.60 V/C Ratio < 0.95? General Traffic YES NO In at least one peak hour Slack Time* > 5 Seconds YES NO TSP is Feasible. Weighting Factors - Overall Corridor Ranking - Cross Street Facility Type - Other Priority Treatment Exists - Bus Delay on Approach (Bus Speed) - Peak Hour Bus Passengers by Direction - Bus Frequency Transit Design and Service Intersections Ranked by Corridor and Potential Benefits * Slack Time = Cycle time minus all minimum pedestrian clearance and minimum left turn green times Initial Screening ~ 200 Intersections

15 Countywide TSP Study Proposed Conditional Criteria Buses 5 minutes behind schedule. First come first served basis (no special consideration to direction, corridor, operator, or type of service). A TSP request will be granted only when it can be accommodated safely within the traffic signal controller phases at the intersection. TSP signal strategy options green extension red truncation. Lockout after a request is granted (3 cycles)

16 TSP Technology Pilot Test Status TSP Technology test fully operation January 2013 Five buses equipped with emitters Three traffic signals equipped with roadside receivers Data collection underway for: late buses detected by roadside equipment late buses reported by ORBCAD Ride On evaluation underway to identify any change in bus on time performance 16

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18 Transit Signal Priority Considerations Countywide versus RTS Countywide Current Ops Current service in mixed flow (no other special treatment) All transit in corridor treated equally Corridors selected on most potential transit benefit with least potential traffic harm First come first served transit priority request granted Person throughput auto and transit equal Traffic signals coordinated for all traffic Traffic coordination allowed to recover between requests TSP options: Green extension (through) Truncated red (through or cross) Within RTS Ops Future service in tandem with RTS ROW and other priority treatments How should RTS, Express, Local & peak in or out be given priority? Corridors from County Transit Functional Master Plan What service gets priority when there are multiple requests? Should RTS service get additional priority? Should signals be coordinated for RTS vehicle flow? How often should priority be granted? New Signal treatment Options: Passive priority Transit only phase 18

19 Purpose: TSP within RTS System Proposed Purpose & Goal Help maintain consistent transit vehicle flows and travel times for RTS Service while reducing delays due to stops at traffic signals. Goal: Improve expected Transit Travel Times for travelers using the RTS system through improving reliability and reducing delays without undo negative impacts to the overall transportation system performance or other travelers.

20 Transit Signal Priority within RTS Signal Priority Options Within Mixed Flow Operations (as before) Extend Green Phase Truncate Red Phase With RTS Right of Way treatments or queue jump lanes (new options) Passive Adjusts signal coordination to support unimpeded flow of transit vehicles within corridor Exclusive Transit Phase Provide a transit only phase for transit vehicles at intersections

21 Transit Priority Treatment versus Signal Operations Potential Signal Treatments* ROW Treatments Passive Extend Green Red Truncate Non-RTS Corridor Mixed Flow Mixed Flow w Queue Jump Dedicated Curb Lanes Managed Lane (dedicated 1 way Pk) 1 Lane Medan Busway (bi-dir) Insert Transit Phase Transit only Early Green 1 Lane Median Busway (1 way) 2 Lane Side Busway (2 way) 2 Lane Median Busway (2 way) LRT ROW (Purple Line) * Also depends on allowed turns and transit service in guideway

22 Other Characteristics Impacting TSP and Signal Operations Turns Permitted Traffic Transit Service in Priority ROW ROW Treatments Right Left Lane Use LRT RTS Express* Local Non-RTS Corridor Y Y Y N Y Y Mixed Flow Y Y Y Y Y Y Mixed Flow w Queue Jump Y Y Right Trn Y Y Y Dedicated Curb Lanes? Y Right Trn Y?? Managed Lane (dedicated 1 way Pk)? Y Right Trn Y?? 1 Lane Medan Busway (bi-dir)?? N Y? N 1 Lane Median Busway (1 way) Y? N Y? N 2 Lane Side Busway (2 way) Y Y N Y? N 2 Lane Median Busway (2 way) Y N N Y? N LRT ROW (Purple Line)?? N Y? N N * Non-RTS WMATA, MTA, etc. Factors X street Fac. Type Primary Secondary Local X street Transit Service RTS High Freq Low Freg Bus stop location Near Far Bicycle & Pedestrian Priority Area Excess Ped Time HCM V/C Ratio >0.6 <0.95 Available Green time(phases) Non-TSP phases > 1 Time Since Last TSP Accuation 3 cycles for non-rts corridor Ridership Assume ridership > 100 pass /direction / hour

23 Emerging Technology The US DOT Connected Vehicle Program DSRC real time short range communications between vehicles and/or roadside Transit vehicles can be aware of each other, and downstream or cross-street conditions Smart vehicles with real time information Developing applications and conducting pilots now New System Components Priority Request Generators and Servers to address multiple simultaneous requests Automatic Passenger Counters Predictive and coordinated priority progression (along a corridor)

24 Transit Signal Priority Policy Questions How should potential signal operations change when combined with other priority treatments options (queue jumps, exclusive guideway, etc.)? What types of transit service will be eligible for signal priority (RTS, Express, Local) and in which directions (peak, off-peak, cross)? How often should priority be granted when requested? What weights should be given to transit ridership versus general traffic? Should the TOC be integrated or separate? How should we plan to evolve with Advances in Technology (e.g. Connected Vehicles)

25 Key Findings Council resolution shifts TSP decisions based on ROW treatment to Facility Planning stage Detailed operational review and recommendations by corridor and intersection delayed equipment modifications/upgrades, detection parameters, active priority strategies traffic control system parameters Predicted high frequency of RTS service in many corridors (less than 5 minute headways) requires rethinking on how to apply TSP (Schedule versus Headway management) High level recommendations that can be provided now Overall TSP system parameters TSP treatments for each type of right of way Key decisions needed in facility planning, Next steps to facilitate TSP integration and deployment 25

26 Key Findings 10 Route RTS network has 116 stations overlaying 288 existing traffic signals and 820 existing bus stops 126 of the 288 signals in the RTS corridors are included in the Countywide Study recommendations for TSP implementation for current service 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 Primary traffic control system function is to monitor signal performance for roadway safety and mobility Incorporating WMATA buses into RTS would require additional hardware and software, cost TBD 26

27 Schedule Versus Headway Management Schedule Management: Less Frequent Service (e.g. Headways > 10 minutes) Scheduled Time 8:30 am Arrival Time 8:40 am 10 minutes Late TSP Request Sent Conditional Priority Threshold: 5 minutes behind schedule Headway Management: Frequent Service (e.g. Headways < 10 minutes) Desired headway = 6 minutes Gap > Threshold TSP Request Sent Actual Gap = 11 min. 5 minutes behind Conditional Priority Threshold: Gap 1.5 times desired headway = 9 minutes

28 Early RTS Corridor Recommendations (1) TSP deployed at all signalized intersections in RTS network with activation based on conditions at each intersection for each time period Decentralized TSP architecture Co-located Operations Center Separate RTS operations and control Real-time interfaces between ATMS, RideOn, and RTS RTS operations center to vehicle real time communications of headway (gap) status for headway control Initial Technology and Equipment Econolite ASC/3 controller Current Montgomery County ATMS system GTT Opticom TSP system AVL/CAD with APC on all RTS vehicles

29 Early RTS Corridor Recommendations (2) Exclusive Guideway: Only RTS vehicles can request/receive TSP Mixed Flow & Queue Jump: All Transit service can request/receive TSP TSP signal strategies supported by the initial technologies (without significant upgrades to software or hardware): Early Green, Extended Green, Leading Green/Transit Only Phase Insertion Conditional TSP to support Schedule adherence of RTS service within the RTS corridors (Headway > x minutes) Conditional TSP to support Headway adherence of RTS service within the RTS corridors (Headway <= x minutes) Conditional TSP to support prioritization by: Service Type (RTS, Express, Local) Direction by Time of Day (peak, off peak) Historic passenger loading

30 James (Jim) Allday Bunch Senior Transportation Planner Thank you Sabra, Wang & Associates, Inc Samuel Morse Drive, Suite 100 Columbia, MD Main Direct Fax

31 BACKUP SUPPORT SLIDES

32 1. Example: Active Priority; Actuated Transit TRANSIT LANE or QUEUE JUMP Phase, Distributed System 1 2 Priority Request Generator VEHICLE LOCATOR Priority Request Server 3 TRANSIT SIGNAL APPROACHING TRANSIT VEHICLE 4 SIGNAL CONTROLLER 32

33 Measures: Transit Characteristics Stop location Near Far Other Priority Treatments (existing, potential) Dedicated lane Queue jump Bus bulbs Signal Delay per vehicle (by approach; AM, PM, Midday; Local, limited, express; etc.) % with delay Average delay Distribution (will be skewed) % GT X Transit Service Vehicles per hour (by approach; AM, PM, Midday; Local, limited, express; etc.) Vehicles per hour routing, straight, left, right (by approach; AM, PM, Midday; Local, limited, express; etc.) Passengers per vehicle (by approach; AM, PM, Midday; Local, limited, express; etc.) % Vehicle trips on time (by approach; AM, PM, Midday; Local, limited, express; etc.) Impact on transit progression (do we want to tie priority together for groups of signals, e.g. Us29 at University).

34 Performance Measures: Traffic Characteristics Volume (by approach; AM, PM, Midday) Intersection LOS (by approach; AM, PM, Midday) Queue length, average, max (by approach; AM, PM, Midday) Delay, average, max (by approach; AM, PM, Midday) Volume-to-Capacity Ratio (by approach; AM, PM, Midday) Available green (by approach; AM, PM, Midday) Corridor/mid block LOS (is the intersection impacted by other near by intersections, is upstream congestion significant) Pedestrians and bicycles per hour Signal Controller type and capabilities Coordinated? Boundaries? Timing (phases, actuated, AM, PM, Midday) cycle length Physical Number of lanes by type and approach Pedestrian and bicycle features (actuated request, bike lanes, pedestrian island, accessibility)