adaptive traffic signals - louisiana · for each detector channel during the last cycle. values are...
TRANSCRIPT
www.dotd.la.gov
Ben Boudreaux, PE, PTOE
Assistant Traffic Operations Engineer
District 07
Adaptive Traffic Signals
Adaptive Systems in District 07
1st Adaptive System (6 Signals)– I-10 EB & WB Exit Ramps in Westlake
– LA 378 Corridor
– Installed October 2017
2nd Adaptive System (7 Signals)– LA 108 Corridor in Sulphur
– Isolated Signals on US 90 & LA 27
– Installed July 2019
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What is an Adaptive Traffic Control Signal?
Real-time adaptive traffic control System
Adjusts signal timing based on current traffic– Establishes Cycle Lengths of entire corridor
– Adjust Split Times
– Adjust Offsets
Updates signal timings cycle by cycle
Long list of Manufacturers
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Parts of an Adaptive System
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Combustion Triangle
Ignition Source
Adaptive System
Adaptive Server
Parts of an Adaptive System
Detection– Magnetometers
– Video
– Loops
– Radar
– Others
Adaptive Server– Manufacturer Dependent
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Communication– Fiber
– Cellular
– Wireless
– Cup and String
Detection for Adaptive
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D2 D2
250’-500’
Back
Standard
Stopbar Detection
Advanced Detection
(Adaptive)
Adaptive Detection
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How Adaptive System Works
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Stopbar Detection
Adaptive Detection
Stopbar Detection
Adaptive Detection
Stopbar Detection
Adaptive Detection
Where Adaptive Systems Perform Well
Changing Traffic Patterns– Seasonal Traffic
– Large Trip Generators
– School
Random Traffic Changes– Detoured Traffic
– Temporary Lane Closures
– Sporadic Event
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Where Adaptive Systems Perform Well
Triggered Events – Emergency Evacuation
– User Defined Action
– Rapidly Clear Queue (Flush)
– Clear Sporting Venues
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Example Venue
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Advantages of an Adaptive System
Potential to Reduce Motorist Delay
Potential to Increase Capacity
Provide More Control/Options
Utilize Existing Infrastructure
Performance Measure Reports
Reduction of Crashes (2018 Study)
Reduce Emissions
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Disadvantages of an Adaptive System
Not Set and Forget
Requires Manpower to Properly Monitor &
Maintain.
Requires Operation of Additional
Components (Detection, Communication, &
Server).
Still Need Fallback Timing Plans
Additional Cost
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Westlake Adaptive System
In response to Sasol LNG Expansion
(installed by permit).
Utilize Magnetometer Detection (Primarily)
Utilize Video Communication for Stopbar
detection at 2 intersections.
Utilize Non-Licensed Radio and Cellular
Modems for communication.
Has a preemptive flush trigger for Interstate
Exit Ramps.
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Westlake Adaptive System
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Westlake Adaptive System
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Westlake Adaptive System
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Westlake Adaptive SystemObservations
Large Cycle Times
Long Splits on Mainline
Manageable Queues on Side Streets
Maintain Fair Progression
Most issues have been due to
magnetometers failures and communication
A few server issues.
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Westlake Adaptive SystemPerformance
Crashes– Intersection 1 (increased from 7 to 10)
– Intersection 2 (decreased from 13 to 11)
Travel Time– Slight Reduction
Complaints– Minor
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Westlake Adaptive SystemPerformance
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Westlake Adaptive SystemPerformance
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PRE
POST
LA 108 Adaptive System
In response to Axial Expansion, with some
signals funded by Sasol (installed by permit).
Utilize Radar for both Stopbar and Advanced
Detection.
Utilized wireless (Radio) for communication.
Alternative to Signal Retiming
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LA 108 Adaptive System
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LA 108 Adaptive System
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LA 108 Adaptive System
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LA 108 Adaptive SystemObservations & Performance
Cycle Times Slightly Larger during Peaks
No Reduction in Throughput Travel Time
Maintain Fair Progression
No Complaints
Need Additional Observation
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Travel Time Comparison
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Travel Time Comparison
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Communications of Adaptive Traffic Signals
Clarke Chauvin, PE, PTOEProject Engineer
Intelligent Transportation Systems, LLC.
Vehicle Detection Video Detection - Coaxial Radar Detection - Serial Magnetometer Detection - Wireless
IP Devices ATMS Controller Ethernet Switch CCTV Camera Bluetooth Detection
Local Communication
Cellular Modem Private Cellular Network
Used for isolated signal communications
Unlicensed Wireless Ethernet Radio 2.4 GHz range
5 GHz range
Used for signal corridor communications
Fiber Optic Cable Used to connect signal corridors to adaptive server
Backbone Communication
Wireless Radio
Cellular Modem
Rugged Ethernet Switch
Example Corridor Communications
Performance
Bluetooth Detection
Communications
PRTG
ATMS.now
System Monitoring
Adaptive User Interface
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Adaptive User Interface
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Adaptive User Interface (ATMS)
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Adaptive User Interface (ATMS)
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Ivica KlanacSystems EngineerCubic/Trafficware
Adaptive Management System
SYSTEM TOPOLOGY
• SynchroGreen Central Server
• SynchroGreen Local Intersections
• Detection
• Algorithm
CENTRAL SERVER/APPLICATION
• ATMS.now and SynchroGreen interaction– SynchroGreen is a SEPARATE application from ATMS.now
– ATMS.now can be used to change SynchroGreen settings and monitor commands
– ATMS.now is used to review historical data and troubleshoot events
– SynchroGreen can be on the same or separate server than ATMS.now
– Only ONE server can run SynchroGreen
OPTIMIZATION ALGORITHM
CYCLE / SPLIT OPTIMIZATION
CYCLE / SPLIT OPTIMIZATION
Target Phase Allocation =Green Utilization
Detector Calibration Factor (DCF)
With the same Green Utilization…A lower DCF results in a higher Target Phase allocationA higher DCF results in a lower Target Phase allocation
• Travel path optimization
• More volume, means more bandwidth
• Adjusts for queues
• Adjusts for trending early/late arrivals
OFFSET OPTIMIZATION
SYNCHROGREEN WEB INTERFACE
STATUS
Active/Inactive
Current datasheet
What intersection is running (Visible in ATMS)
>70% for SSM activation
Not Running Command
Pattern / Mismatch
Outside Tolerance
Not Coordinated
× Stale Command
× Cycle Zero Window
× Error calculating new plan/pattern
× Error optimizing to target cycle/greenband
STATUS
What is being sent to the controller
Green utilization for last phase
What controller wants to run based on demand and user constraints
Green Utilization / Next Split (estimate how much time next split is at saturation flow)
Green utilization error
M: Exceeds Max Utilization
D: NTCIP Detector Fault (e.g. Max Presensce)
INTERSECTION DATABASE
User input data that control how SynchroGreen calculates splits, patterns, and offsets at each intersection; and by extension, the entire group
INTERSECTION DATABASE - DEFINITIONS
Minimum/Maximum Cycle; Rate of Change
Minimum/Maximum Green Band
Minimum/Maximum Split; Rate of Change
Sets the Detector Calibration Factor
Stop bar detectors
Advanced detectors
Special Functions
INTERSECTION DATABASE – MINIMUM / MAXIMUM CALCULATIONS
• Minimum split and cycle length:• User defined minimum values
• SynchroGreen will not send calculate a split or cycle length that violates those values
• Quick notes:• SynchroGreen DOES check the Minimum Phase
values (MinGreen, Yellow, Red, Stop-in-walk, Shortway) and will use the higher between whats programmed and MinAllocation
• The ‘effective’ lowest cycle can be higher than the MinCycle if the sum of phases is greater than MinCycle
INTERSECTION DATABASE – GREEN UTILIZATION, ARRIVAL DETECTORS
• Used to measure Green Utilization on each phase
• Assign all the detectors on each phase
• Four Detectors max per phase• If more than 4 detectors on a phase, choose the
detectors with the highest green utilization
• Arrival Detectors are used to be measure counts on the advanced detectors and adjust relative offsets• If more than 2 detectors on a phase, choose the
detectors where traffic is not affected by turns. Typically, it’s the inside lanes
INTERSECTION DETECTOR STATUS
Lists the Occupancy (sec)and Volume measuredfor each detector channelduring the last cycle.
Values are smoothed.
Used for triggeractivation.
• Equipment Failure
Detector Fault
Communication Fault
• Traffic Conditions
Percent Utilization
Detector Occupancy
Detector Volume
TRIGGERS – TYPES AND APPLICATION
• Detector Fault
If detectors at this intersection fail, the System response will cause traffic conditions to be much worse than TOD
• Communications Fault
If communications at this particular intersection fail, continuing adaptive operations will cause traffic conditions much worse than TOD
If communications any intersection in this group fail, continuing adaptive operations will cause traffic conditions much than TOD
TRIGGERS – EQUIPMENT FAILURE
• Condition
Multiple Detector Failures
Detectors Fail on an Approach
TRIGGERS – DETECTOR FAULT
• Response
Shut off and run TOD
Change Intersection Pattern w/ Recalls
Change Intersection SG Database with different Min Allocations / Detector Calibration factors
• Condition
Lose communications to a specific controller
Lose communications to any signal in a group
TRIGGERS – COMM FAULT
• Response
Shut off and run TOD
ATMS.NOW & SYNCHROGREEN
• ATMS functions critical to SynchroGreen
• SynchroGreen Reports
• Purdue Reports
Summary
Adaptive Systems are not a Fix All
Adaptive Systems are not a set and forget.
Adaptive Systems require operating
detection, communication, & server.
Adaptive Systems can improve Travel Time
and Delay, as well as reduce Emissions.
Adaptive Systems can reduce crashes.
Adaptive is another tool to evaluate a
corridor’s performance.
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GO LSU
www.dotd.la.gov
Contact Information
Ben Boudreaux, PE, PTOE
337-437-9235
Ivica Klanac
Clarke Chauvin, PE, PTOE