Going Green by Flashing Yellow

Transcription

1 Going Green by Flashing Yellow Transportation Education Series Southeast Florida Presented by: Shaun Quayle, P.E. Shing Tsoi, P.E.

2 Presentation Overview Introduction Background of Flashing Yellow Arrow (FYA) Warrants of Protected/Permissive Left-Turn Phasing Implementation Considerations Case Studies: Washington Co. OR 370+ FYA Implementation Safety Cost/Benefit Analysis Advanced FYA Applications Research Key Points to Take Home

3 Introduction Introduce yourself Name and association you working with Who has FYA installations in their jurisdiction? How many? What has been your experience?

4 What s all the Confusion?

5 What s all the Confusion?

6 Background of Flashing Yellow Arrow (FYA) NCHRP 3-54 Research Project Recommended FYA Display Included in 2009 MUTCD NCHRP Project 20-7/Task 222 Evaluation of FYA

7 NCHRP 3-54 Research Project Final NCHRP Report > 2004 Project objective: to evaluate the safety and effectiveness of different signal displays used with protected/permissive left-turn (PPLT) control

8 NCHRP 3-54 Research Project Display Performance Goals Clearly distinguish between protected & permitted Minimize confusion Reduce assumption of right-of-way Eliminate yellow trap Allow protected-only or permitted-only Eliminate need for: Special signing Special lenses or louvers

9 Yellow Trap

10 Yellow Trap

11 Yellow Trap Flashing Yellow Solution Yellow Trap Flashing Yellow Solution

12 NCHRP 3-54 Research Project Experimental Sites 4 experimental sites in Broward County Broward SW 69th Ave (FYA not exist now) Coral Springs Wiles Rd (see video on next slide) Sample Riverside Dr (FYA not exist now) Lyons Sawgrass Expressway (two FYA locations) Other sites: Montgomery County, Maryland City of Tucson, Arizona Jackson County, Oregon Oregon Department of Transportation City of Beaverton, Oregon

13 NCHRP 3-54 Site: Coral Springs Wiles Rd

14 NCHRP 3-54 Research Project Experimental Sites Coral Springs Wiles Rd

15 Citizen Response Positive Go Indication of Green Ball can be confusing

16 NCHRP 3-54 Summary Findings FYA equally understood to green ball FYA showed fewer fail critical responses Field data supports high level of driver understanding of FYA

17 Recommended PPLT Display 4-Section FYA, all arrow display face should be the only display allowed 3-section bimodal Green/FYA

18 Included in 2009 MUTCD FHWA provided interim approval in 2006 Section 4D Signal Indications for Left-Turn Movements General Provides both 4-section and 3-section display 3-section display requires justification

19 NCHRP Project 20-7/Task 222 Scope included all known installations of the FYA prior to July

20 Empirical Comparison: PPLT to FYA PPLT Average Annual Crash Frequency Comparison of Before and After Crash Frequency at Intersections Converted from PPLT to FYA PPLT ODOT_Beaverton, OR Kennewick, WA Kennewick, WA NCDOT_Harnett Co., NC Total Crashes Before FYA (Annual) Total Crashes After FYA (Annual) NCDOT_Harnett Co., NC Snohomish Co., WA Snohomish Co., WA ITD_Nampa, ID Lacey, WA Alexandria, VA Alexandria, VA ITD_Nampa, ID Broward Co., FL Beaverton, OR Beaverton, OR Beaverton, OR ODOT_Woodburn, OR Jackson Co., OR ODOT_Woodburn, OR Jackson Co., OR

21 Average Crashes Over Time PPLT to FYA PPLT Average Change in Total Crashes at Intersections Converted from PPLT Control to FYA PPLT 0% 25 Percent Reduction in Total Crashes -20% -40% -60% -80% -100% Average Difference in Crash Frequency Number of Intersections Number of Intersections Meeting Criteria -120% Minimum Number of Months of Crash Data After Implementation

22 NCHRP 20-7 Conclusions Conversion Average Annual Crash Frequency PPLT to FYA PPLT Prot. to FYA PPLT Perm. to FYA PPLT Reduced Increased Mixed Results

23 Other Research Results Qi, Zhang, Wang and Chen. Safety Performance of Flashing Yellow Arrow Signal Indication (2011) 4 intersections in Tyler, Texas; 13 in Kennewick, Washington; with additional 14 in Sugarland, Texas Circular Green PPLT to FYA PPLT Left-turn crash rate decreased for most study intersections (27 out of 31) Recommend delay setting on FYA indication

24 Guidance on Protected/Permissive Left-Turn (PPLT) Phasing FDOT PPLT Design Guidance: Traffic Engineering Manual Intersection Design Guide Plans Preparation Manual PPLT should be used unless there is a compelling reason not to (TEM)

25 Considerations for Protected/Permissive Left-Turn (PPLT) Phasing Protected LT SHALL be used when: Two or more LT lanes Geometric conditions and sight distance Lead-lag phasing is used (assuming 5-section doghouse is used) Offset LT lanes such that visibility of shared signal display becomes an issue

26 Other Considerations for PPLT Phasing Protected LT MAY be preferred when: Speed limit > 45 mph LT crosses three or more lanes More than 6 LT crashes per year on an approach Unusual intersection geometrics, such as restricted sight distance

27 Florida Laws and Manuals on FYA FDOT Traffic Engineering Manual: Option: A flashing YELLOW ARROW signal indication may be displayed to indicate a permissive left-turn movement in either a protected/permissive mode or a permissive only mode of operation. Florida Driver s Handbook: A flashing yellow arrow means left turns are allowed. Yield to oncoming traffic and pedestrians. The oncoming traffic has a green light. Florida Statute: No specific language regarding FYA

28 Implementation Considerations Retrofit Considerations 4-section vs. 3-section display Cost and equipment

29 Retrofit Considerations Two types of retrofits: 3-section protected lefts to protected/permissive FYA 5-section protected/permissive doghouse to FYA Many agencies are considering retrofits

30 Retrofit Considerations Traffic signal controller compatibility with FYA PPLT displays Evaluate system compatibility Controller models (Naztec, BiTrans, etc.) and firmware versions Channels/Load switch requirements

31 Retrofit Considerations Configuration of conflict monitor and program card Monitoring more than 16 channels Through Greens (4), Left-Turn Greens (4), Walks (4), Overlaps (4), & FYA (4) 18 or 20 channel conflict monitor Avoid Hard-wiring where possible Avoid issues with overlaps and FYA

32 Retrofit Considerations Lane Alignment & Mast Arm Length Source: MUTCD

33 Retrofit Considerations Mast arm length Traffic signal pole and mast arm structural design Reduced wind loads from signs Potential addition of second through signal (increased dead load)

34 Retrofit Considerations Vertical clearance at the new FYA display Electrical wiring needs to serve the new display Pre-emption equipment compatibility

35 Retrofit Considerations Ensuring a second through lane signal display is available Intersection geometry Sight distance Pedestrian conflicts/ interaction

36 4-section vs. 3-section display 4-Section Vertical clearance for extra signal face Span-wire requires special bracket Each display separate face in signal display

37 4-section vs. 3-section display 3-Section Vertical clearance height - no change Flashing yellow and solid green arrow share face in signal display

38 4-section vs. 3-section display 3-Section Exception in Jackson County: Flashing yellow and solid yellow share face in signal display

39 Cost and equipment Conversion of doghouse 5-section head to 4-section FYA PPLT signal Include new controller unit/controller upgrade, if needed Remove 5-section doghouse head Add 3-section through head plus FYA signal head Maintain existing traffic signal mast arm pole Approximate cost is $3,500 to $4,500 per approach Cost estimate excludes engineering assessment, mobilization, temporary protection and direction of traffic, and flaggers, which depend on the size of the project

40 Cost and equipment Conversion of 3-section protected head to 4-section FYA PPLT signal Include new controller unit/controller upgrade, if needed Replace protected 3-section with FYA signal head Maintain existing traffic signal mast arm pole Approximate cost is $2,500 to $3,500 per approach Cost estimate excludes engineering assessment, mobilization, temporary protection and direction of traffic, and flaggers, which depend on the size of the project

41 Cost and equipment Conversion of 3-section protected lens to bi-modal head creating 3-section FYA PPLT signal Include new controller unit/controller upgrade, if needed Replace bottom protected lens with bi-modal lens Maintain existing traffic signal mast arm pole Approximate cost is < $1,500 per approach Cost estimate excludes engineering assessment, mobilization, temporary protection and direction of traffic, and flaggers, which depend on the size of the project

42 Cases of supplementary FYA signage Richardson, TX Burnsville, MN

43 FYA across the Nation Over 40 states have FYA implemented Oregon is one of the first states to implement FYA Case Studies: Washington County (Oregon) FYA Implementation Anchorage (Alaska) Cost/Benefit Analysis for FYA Advanced FYA Applications

44 Washington County (Oregon) Experience Background ARRA Funding System-wide implementation Public Involvement Findings/Feedback since implementation Lessons learned (Where didn t it work?)

45 Background Cities of Woodburn and Beaverton were early adopters Installations at Nike Campus showed benefits Commence developing a program Some installations through capital project mngmnt & retrofits First 12 installations with maintenance $$ More expensive Seeking more public exposure Funding Senate Bill 994 (2007) ARRA

46 American Recovery and Reinvestment Act (ARRA) Funding Prospectus Project included replacing programmable heads with arrow signal indications Flashing Yellow Arrows: Increase in overall intersection capacity and a large reduction in driver frustration Illuminated Sign Replacement: Energy savings, as well as maintenance of interior illuminated signs System-wide conversion during the Summer of 2010 ~$485,000 (~$1,500 per approach) FYA component less per intersection

47 System-Wide Implementation Installed 372 bimodal FYA signal heads at 174 key intersections at locations with: Mainly Protected-only to Protected/permissive County implemented FYA on DOT and City facilities Chose to implement the 3-section displays

48 System-Wide Implementation Traffic signal pole assessment County s assessment indicated that 4-section acceptable ODOT needed structural calculations (latest AASHTO) Based on intersections along Beaverton-Hillsdale Highway, entire contract was changed to 3-section bimodal heads which allowed more intersections to be done Bimodal head ~$115 each Photo s Lee Rodegerdts

49 System-Wide Implementation

50 System-Wide Implementation

51 System-Wide Implementation

52 System-Wide Implementation

53 System-Wide Implementation

54 System-Wide Implementation

55 System-Wide Implementation 2011 & Future

56 Previous FYA Installation Costs NIKE Project 3 Section Protected to 4 Section Prot./Perm. Total # of Approaches 6 Construction Cost per Approach $2,500 Washington County First 12 3 Section Protected to 4 Section Prot./Perm. Total # of Approaches 21 Construction Cost per Approach $1,540 ARRA Project 3 Section Protected to 3 Section Prot./Perm. Total # of Approaches 340 Construction Cost per Approach $790

57 Public Involvement Never enough Illustrate concepts / animation Public awareness campaign/media outreach LJ1r9Us Agency feedback Scarcely ever in the history of Washington County s Department of Land Use and Transportation have we introduced a new transportation feature that has had so great an impact and been so well received.

58 Public Involvement Public feedback The new signals are a welcome surprise that helps to improve traffic flow. Instead of waiting for several minutes as a single car turning left, I now have the flexibility to yield and proceed without interrupting other traffic. Thank you! Thank you, a thousand times, for installing the flashing yellow signal at the intersection of Murray Blvd. and Sexton Mountain Road! I can t tell you how much time I ve wasted waiting at that intersection in the past 15 years, but now it s fixed. I m delighted, so is my wife. Good work!

59 Findings/Feedback Since Implementation Why not my street? Pedestrian issue; walk against FYA Less congestion Better progression (lead or lag) Less queue spill back Combination of FYA & signal retiming

60 Lessons learned - Where didn t it work? Sight distance adequacy (curvilinear approaches & skewed intersections) Gap acceptance Opposing exclusive right-turn lanes Confusion: who has right of way? Conflicts with pedestrians/bikes Motorist looking for gaps in approaching vehicle stream Poor access management Take gap but run into stopped vehicle

61 Lessons learned - Where didn t it work? Murray Blvd

62 Poor Driver Behavior Taking unacceptable gaps Honking or going around waiting drivers Failing to yield to bicycles Failing to yield to pedestrians

63 Creeps

64 Creeps

65 The Nut That Holds The Wheel Smithsonian Museum of American History 2012

66 Findings/Feedback Since Implementation Crashes increase Insert video of ped/bike conflict (2820?, car running red?)

67 Expected Crashes Conversion Average Annual Crash Frequency PPLT to FYA PPLT Prot. to FYA PPLT Perm. to FYA PPLT Reduced Increased Mixed Results Crash Modification Factors Clearinghouse: - Conversions from protected to protected-permissive, expect 65% increase in angle crashes.

68 FYA Crashes Over Time Evergreen Parkway at Stucki Days since FYA was installed Cumulative Crashes

69 Operational & Environmental Benefits Delay Reduction: 40% 40% 50% Fuel Consumption Reduction: 15% 15% 20% Murray Blvd: reduce stops by ~18% Bethany Blvd: reduce delay by ~35% Evergreen Rd: reduce fuels by ~13%

70 Environmental Benefits of the FYA Less idle time Reduces stops Decel + Accel = Heavy emissions Protected left-turn movement not needed as often, thus less opposing traffic stops Less idling and decel / accel of through traffic Can allow for more progression of through traffic Fewer emissions

71 Operational Benefits of the FYA Eliminates motorist confusion. Eliminates the left-turn yellow trap problem under all conditions and phase sequences. Efficient use of time within the signal cycle. Requires no supplemental signing.

72 Operational Benefits of the FYA It can be used in all intersection and signal configurations T s, Four-leg, 2-way meeting 1-way, etc. It does not require optical shielding or precise placement It allows explicit control of the permissive movement (separate from the through movement) It can also be used for right turns.

73 Anchorage Case Study Review of top 8 intersections ( ) 173 left-turn crashes (26%) ; 62 injury (9%) Left-turn vs. opposing through/right volumes ADOT Staff Eliminate yellow trap; enhance safety FYA TOD controls; shift between Prot, PPLT, and Perm.

74 Anchorage: Benefit/Cost 30% Reduction in LT Crashes (Doghouse to FYA) Alaska 2011 Highway Safety Improvement Handbook

75

76 Anchorage: Benefit/Cost Summary All B/C >1.0 Ranges from 2.7 to 28.4 : 1 Estimated 30% crash reduction Follow up after crash analysis in 3 years New poles & mast arms, controller/software, and 4-section heads for all 15 approaches Construction cost estimate $1,275,000

77 FYA Signal Control: Mobility & Safety and Advanced Applications FYA treatment in controllers (170 vs. 2070) Balancing safety and mobility FYA Advanced Features FYA delay Time of day (FYA) Gap-dependent (dynamic) (FYA) Pedestrian friendly FYA

78 FYA Signal Control in 170 Controllers (BiTrans) Row Column Numbers ----> E 0 Exclusive Phases 1 RR-1 Clear Phases 2 RR-2 Clear Phases 3 RR-2 Limited Service 4 Prot / Perm Phases Flash to PE Circuits 6 Flash Entry Phases 7 Disable Yellow Range 8 Disable Ovp Yel Range 9 Overlap Yellow Flash A EV-A Phases B EV-B Phases C EV-C Phases D EV-D Phases E Extra 1 Config. Bits F IC Select (Interconnect) Configuration <C+0+E=125> BiTrans 233 RV2 Ext. Permit 1 Phases Ext. Permit 2 Phases Exclusive Ped Assign Preempt Non-Lock Ped for 2P Output Ped for 6P Output Ped for 4P Output Ped for 8P Output Yellow Flash Phases Low Priority A Phases Low Priority B Phases Low Priority C Phases Bi Low Priority D Phases Restricted Phases Extra 2 Config. Bits _2 <C+0+E=125> Configuration F BiTrans 233 MC1 Row 0 Column 8 Reserved 1 Reserved 2 Reserved 3 Reserved 4 Reserved 5 Reserved 6 Reserved 7 Reserved 8 Flh Yell Arrow Green 1 18 A Flh Yell Arrow 3 0 B Green 3 0 C Flh Yell Arrow 5 36 D Green 5 34 E Flh Yell Arrow 7 0 F Green 7 0 Assignable Outputs <C+0+E=127>

79 FYA Signal Control in 2070 Controllers (Naztec) Version 61.X (TS2) Version 65.X (2070) (from Naztec controller manual) (from Naztec controller manual)

80 Balancing Safety & Mobility

81 Balancing Safety & Mobility

82 FYA Signal Control Advanced Concepts Dynamic Control FYA Delay Time-of-Day Based FYA Gap-Dependent or Dynamic FYA Pedestrian-Friendly FYA Logic Safety Mobility

83 FYA Delay Insert link (VIDEO 2839, first seconds)

84 Time-of-Day FYA Disable FYA by time of day, or. Gap-Dependent FYA Oregon Washington County Beaverton ODOT Kennewick, Washington Sugarland, Texas Etc.

85 Gap-Dependent (Dynamic) FYA

86 Time-of-Day FYA Washington County, Oregon Crash Ranking: 6/262 Phase 1: TOD FYA during Weekdays and Saturday Phase 2: Gap- Dependent FYA based on Phase 1 observation

87 Pedestrian-Friendly FYA Problem Contributing factors Solution concept Solution Solution logic flow Free & Coordinated Operations Solution Logic Covers Various Conditions Alternate Approach without Pedestrian Detection

88 Problem Problem: Permissive Left-Turns & Pedestrians Both receive positive go guidance Law requiring yield/stopping (Florida Statutes (a)(1)) Photo: Courtesy of WACO vehicular traffic, including vehicles turning right or left, shall yield the right-of-way to other vehicles and to pedestrians lawfully within the intersection or an adjacent crosswalk at the time such signal is exhibited.

89 Contributing Factors Traffic Volumes Thresholds for protected vs. PPLT vs. Perm Pedestrian volumes Quality of Lighting Street Lighting Sun Glare Pedestrian Volume & Type Children present (schools/parks) Recreational/Trail routes Driver Behavior Photo: Lee Rodegerdts Awareness of pedestrians and bicycles Others Countdown pedestrian heads more late crosswalk entry Intersection skew Sight distance

90 Contributing Factors High Traffic Volume, Limited Gaps High Speeds & Low Traffic Volumes

91 Solution Concept Presenting either the FYA or the pedestrian crossing indications (walk/fdw), not both simultaneously. Physically separate signal indication to clarify priority in the system. First come, first serve logic pedestrian call or FYA active first? Requires pedestrian actuation No conflicting pedestrian = normal FYA operations

92 Solution Logic Flow If ped arrives first, or If FYA already active

93 Solution Logic Flow Ped First

94 Solution Logic Flow Ped First

95 Solution Logic Flow Ped First

96 Solution Logic Flow Ped First INSERT VIDEO (2822, first 0:55)

97 Solution Logic Flow FYA First

98 Solution Logic Flow FYA First

99 Solution Logic Flow FYA First

100 Solution Logic Flow FYA First INSERT VIDEO (2827, all 1:18)

101 Solution Logic Covers Various Conditions Logic code includes the following functions: Suppress FYA indications during ped service Recover or Omit FYA indications after ped is served Accommodate special situations such as: Emergency vehicles Coordination plan transition Combination of free/coordinated operations

102 Alternate Approach without Pedestrian Detection Absence of pedestrian detection Delay start of FYA to allow pedestrians safe entry into crosswalk Delay through walk interval Delay through walk + flash don t walk interval Allow late pedestrian service? Leading pedestrian interval

103 Research ODOT Research: Pedestrian Safety at Flashing Yellow Arrows Oregon State University (Dr. Hurwitz) Portland State University (Dr. Monsere) Washington County (Stacy Shetler) UCF Research: Dynamic Flashing Yellow Arrow (FYA) - A Study on Variable Left Turn Mode Operational and Safety Impacts

104 Project Goal Pedestrian Safety at Flashing Yellow Arrows Determine what conditions at intersections lead to an increase in pedestrian and left turning vehicle conflicts Do drivers look but not see or are they not even looking when presented with an FYA Provide addition guidance as to where FYAs should be installed

105 Pedestrian Safety at Flashing Yellow Arrows Crash data analysis Conflict study Simulator study Model intersections operating FYA Eye Tracking & other measures

106 Dynamic Flashing Yellow Arrow (FYA) - A Study on Variable Left Turn Mode Operational and Safety Impacts Based on an interactive decision and evaluation matrix, and based on the type of data collected in TMCs, a Decision Support System will be developed to systematically flag intersections that require attention. Intersections needing attention will be evaluated for possible FYA application. Miovision Technologies used for data collection on selected intersections. Dr. E. Radwan, Dr. R. Harb, and Mr. Abu-Senna

107 Key Points to Take Home FYA has arrived in the MUTCD Agencies are implementing FYA nationwide with considerable success Provides operational and safety benefits FYA reduces idle time and has environmental benefits

108 Outreach YouTube Resources Tyler, Texas Frisco, Texas Burnsville, Minnesota Washington County, Oregon

109 Key Points to Take Home FYA depends on controller capability FYA Application Naztec BiTrans 233 FYA * FYA Delay (Potential) Time-of-Day FYA (Potential) Gap-dependent FYA Ped Friendly FYA (Potential) * Miami-Dade County operates a different version of BiTrans 233

110 Key Points to Take Home New techniques such as time-of-day FYA are enhancing FYA Consider whether FYA might benefit your community Photo: Lee Rodegerdts

111 Kittelson Experience on FYA Two NCHRP Projects on FYA Feasibility/Benefit Cost Analysis on FYA FYA Signal Design at 20+ Intersections Signal Timing and Implementation for FYA Retiming with FYA Specialty Logic Development and Implementation

112 Kittelson Experience on FYA Active Involvement in National Committee on Uniform Traffic Control Devices TRB Signal Systems Committee Lead Authors on 1 st and 2 nd FHWA Traffic Signal Timing Manual ODOT FYA Sub-Committee

113 Thank You Any Questions? Going Green with Flashing Yellow! Photo: Lee Rodegerdts