and Bicycles at Signalized Intersections NCHRP 03133 Traffic Signal Design and Operations Strategies for NonMotorized Users NCHRP 03133 Traffic Signal Design and Operations Strategies for NonMotorized Users ID: 917801
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Slide1
Integrating Pedestrians and Bicycles at Signalized Intersections
NCHRP 03-133:
Traffic Signal Design and Operations
Strategies for Non-Motorized Users
Slide2Slide3NCHRP 03-133: Traffic Signal Design and Operations Strategies for Non-Motorized Users
Synthesize “state of practice”
Identify and fill information gaps
Develop a guide to help plan/design/operate for non-motorized users
Slide4NCHRP 03-133: Toolbox
Guidance on traffic signal design and operations strategies for non-motorized users in signalized intersections; and
Conceptual framework and set of training materials for practitioners
Slide5Research Opportunities / Questions
What is the “state of practice
”Who is the audience?
Where is the “bar”?Why do people care?What is the actual need?
Slide6Industry Gaps
Source:
NCHRP
Report 812: Signal Timing
Manual,
Second
Edition
Slide7Knowledge Imbalance
Auto
Highway Capacity Manual
AASHTO Green BookHighway Safety ManualMUTCDConnected/Autonomous VehiclesAlternative IntersectionsSimulation and modelingand much more…….
Non-MotorizedSidewalksAmericans with Disabilities Act (ADA) – 1990Public Rights-of-Way Accessibility Guidelines (PROWAG)
Level of Traffic Stress (LTS)
NACTO
Slide8“State of Practice”Many unknownsMisinformationMyths
Fear
BarriersKnowledge base for segments is further along than at intersectionsSeeing is believingSuite of available treatments
Still learning about context and performance
Slide9Challenges
Varying perspectives
ImpactValue
PriorityWide range of environmentUrbanSuburbanRural
Slide10One Size Fits All
Connect to agency capabilities
PoliciesStaff support
MaintenanceContextMore contextAnd…….more context?
Slide11Agency Perspectives
Proactive and Forward Thinking – “Innovators” and “Early Adopters”
Willingness to implement
treatments with best intentionsInterested and Cautious – “Early Majority” Open to test/pilot treatments to learn moreStatus QuoMinimum requirementsNot a priority
Slide12Multifaceted Needs
Project level implementations
Countermeasures
Engineering studies“Reactive” approachPlanning implementationsPolicy supported and drivenPlanning studies“Proactive” approachRange of applications
Slide13Common Project Experiences
Countermeasures
Vision Zero“Spot improvements”
Corridor projectPlanning level analysis not meeting engineering expectationsDesign exceptionsPoliciesTechnologies
Slide14Integrated System Operations
Goals and Objectives
MobilitySafety
DesignPhysical infrastructure and controlEquipmentPerformance monitoring and management
Slide15Treatments
Numerous unique treatments identified
Broad categorization with similar outcomesSET 1: Reduce Pedestrian Delay
SET 2: Eliminating Conflicts with Parallel TurnsSET 3: Mitigating Conflicts with Parallel TurnsSET 4: Improving Ped/Bike Information and EaseSET 5: Bicycle Phases and Special Bike NeedsSET 6: Special Timing Techniques
Slide16SET 1: Basic Treatments to Reduce Pedestrian Delay
Evaluating Pedestrian and Bicycle Delay
Short Cycle LengthMaximizing Walk Interval Length
Recall versus Actuation for Pedestrians16
Slide1717
“Only what’s measured counts”
Policy: Whenever vehicular delay is reported, ped delay must be reported, too.
Basic Treatments to Reduce Pedestrian Delay
“Evaluating Pedestrian and Bicycle Crossing Delay”
Boston Example
Timing Plan 1:
123 s average ped delay
Timing Plan 2:
45 s average ped delay (with 0.5 s increase in vehicular delay)
Slide18SET 2: Eliminating Conflicts with Parallel Traffic Turns
Exclusive Pedestrian Phases
Protected Left Turns on Multilane RoadsConcurrent-Protected Pedestrian Crossings
Delta Islands (Channelized Right Turns) for Ped and Bike Crossings18
Slide1919
Eliminating Conflicts with Parallel Traffic Turns
“Protected Left Turns on Multilane Roads”
1
2
3
US Guidelines: Permitted lefts are
OK unless:
50+ mph speed limit
Crossing 4+ lanes
Crash experience
Contrary to Vision Zero principles
Amsterdam Policy:
On multilane roads, left turns are protected only, never “permitted”.
Slide20SET 3: Mitigating Conflicts with Parallel Traffic Turns
Leading Pedestrian Intervals
Delayed Turn / Leading Through IntervalsFlashing Ped/Bike Crossing Warning
20
Slide21“Delayed Turn”
a.k.a. Leading Bike Interval, Leading Thru Interval, LPI+
21
Mitigating Conflicts with Parallel Traffic Turns
Leading interval (10 s or more)
Charlotte (“LPI-Plus”)
New York, Charlotte: Only with a right turn lane
Montreal: Without a right turn lane
Slide22SET 4: Improving Ped/Bike Information and Ease
Pedestrian Countdown
Bike Wait Countdown
No Turn on RedIndependently Mounted PushbuttonsAccessible Signals without PushbuttonsCall IndicatorsServing Slower Pedestrians
22
Slide23SET 5: Bicycle Phases and Special Bike Needs
Indicating Bike Phases
Detection for Bicycles
Minimum Green and Safety-Based Green Extension for Bikes with Shared Traffic Signals
23
Slide24SET 6: Special Phasing Techniques Favoring
Pedestrians and Bikes
Multi-Stage Crossings - Pointer to all the Treatments that Relate to Multi-Stage Crossings
Pedestrian Phase Overlaps with Each Other, with Bike Phases, and with Vehicular Holds
Re-service for the Ped/Bike PhaseTwo-Stage Left Turn Progression for BikesPedestrian Hybrid Beacon Signals at Intersections with Minor Streets24
Slide2525
“
Re-service
for the Ped/Bike Phase”
Special Phasing Techniques Favoring Peds and Bikes
Reservice
:
twice per cycle
Run free:
on demand, allowing cars 10 s green between ped phases
Slide26Treatment Fundamentals
Documentation/expansion of knowledge base
Consistent set of information (pending if available
)Identification of additional treatment locations and application examples,Illustration of signal timing phasing strategy variations,Graphics to simplify concepts (geometry, phasing)Accessibility considerationsController settings and parametersDocumentation of additional case studies, papers, and/or agency practices, andExpansion of defining context and operating environment.Support for maintenance and operations
26
Slide27Which Pedestrian Mode Should You Use?Pedestrian Recall vs Actuation:
Preliminary Findings
Slide28Pedestrian Recall vs. Actuation
Research Need
Decision involves a tradeoff between
Impact on operations (traffic delay, capacity, progression, cycle length)Impact on pedestrians (delay, compliance/safety)
Short
Medium
Long
Low
Actuation
?
Recall
Medium
?
?
Recall
High
Recall
Recall
Recall
Pedestrian
volume
Vehicle Green Time Need
Pedestrian Volume
Decision
Low
Actuation
Medium
?
High
Recall
Slide29Research Questions
What impacts occur when putting ped phases on recall?
Is there a ped volume threshold to set ped phases on recall?How is it different for peds crossing major street or side street?
Slide30Research Methodology: Base Model
Microsimulation on a real arterial in Virginia (Route 1)
Coordinated-actuated arterial with 110 seconds cycle length
Focusing on a single (test) intersection that is non-critical (i.e., has slack capacity)Modeled both peds crossing main arterial and side street Recall was tested only for peds crossing main arterial (7 sec of Walk and 20 sec of FDW)Crosswalk across side street was set to Rest in Walk
Slide31Research Methodology: Variables
Side street vehicle green time required as a fraction of Min Ped Green time required (denoted as “SSG”)
0.5
0.6
0.70.85
1.0
1.2
Probability of pedestrian demand in a given cycle (denoted as “PP”)
0.1 (4 peds/hr)
0.3 (12 peds/hr)
0.5 (24 peds/hr)
0.7 (42 peds/hr)
0.9 (80 peds/hr)
Slide32Research Methodology: Scenarios and Considerations
Measure delays comparing pedestrian recall modes against variables
Adjustments for probability of pedestrians wanting to cross
Adjustments for side street vehicular demand relative to green timeConsiderations for turning movement volumesCoordinated signal timing factors
Slide33Preliminary Results: Delay Change for Peds Crossing the Main Arterial
With small PP, delay change is nearly equal to Walk time
With high PP, almost no change since ped actuation functions like a recall
Slide34Preliminary Results: Delay Change for Peds Crossing the Side Street
With high SSG, regardless of ped volume, impact is small
Peds Crossing Main Arterial
Peds Crossing Side Street
-7 seconds
59 seconds to 52 seconds
+5 seconds
8 seconds to 13 seconds
SSG=0.5, PP=0.1 Scenario
Slide35Preliminary Results: Intersection Vehicle Delay
With low PP and SSG, more pronounced impact but still less than 3 seconds
With high SSG, almost no impact on intersection delay
Slide36Key Findings
High pedestrian demand:
Pedestrian recall is appropriate and has no impact on intersection delay
Long side street vehicular phase green time required: Regardless of pedestrian demand, pedestrian recall will reduce pedestrian delay with almost no impact on intersection delayLow pedestrian volumes:Pedestrian recall will reduce ped delay by about the same duration of the Walk interval.
Slide37Look Ahead: Define Practice
Linking needs and policies to decision making
Highlighting “context and users”
Proactive planningProject supportIntegrated operations
Slide38Filling in Gaps
Supporting Outcome Based Approach
ConsiderationsUtilizing the Toolbox
ToolboxReference and guidance“Stand Alone” Treatment information sheetsPerformance ManagementMonitoring and measuring
Slide39Key Takeaways
Integrate – not accommodate
Considerations for context and prioritiesChange the status quo
Slide40Thank You