Adaptive Signal System Mt. Juliet, TN. SR-171 (Mt. Juliet Road)

Transcription

1 Adaptive Signal System Mt. Juliet, TN SR-171 (Mt. Juliet Road)

2 Project Background

3 Project Location Mt. Juliet, TN: 2015 Census: 28,159 Doubled since 2000 Immediately east of Metro Nashville Mt. Juliet Road corridor

4 Mt. Juliet Road Corridor Eight signals from Graves Crossing to Pleasant Grove Road 20,000-40,000 ADT within the project limits Major commercial corridor and primary access to I-40 for western Wilson County 1.3 miles in length Primarily 5-lane section

5 Mt. Juliet Road Corridor Primary movements to and from the interstate in the AM and PM peak periods, respectively Regional traffic south of the interstate Heavy volumes in high shopping times with queues 1 mile or more Oversaturation is common Critical intersections: Providence Way/Adams Lane Interstate 40 Westbound Ramps Heavy left turning movements & highest volumes

6 Coordinated & Adaptive Signals

7 Coordinated Signal Systems Coordinated signals: Provides a logical, progressive flow of traffic (platoon) Reduces delay, queues, stops, and emissions for the coordinated movements Synchronize multiple signals in a corridor or on a grid Common cycle lengths Fixed phase time or semi-actuated May increase side street delay

8 Coordinated Signal Systems Fixed time: Pre-determined cycle lengths based on time of day Previously implemented with 3 TOD plans Based on historical data Does not adjust to fluctuating traffic patterns Traffic responsive: Responds to traffic patterns based on current counts/phase failure Typically changes system cycle lengths after multiple cycles Continues for pre-determined lengths of time Requires equipment/detection for traffic counts/phase failure Lacks real-time changes in traffic patterns

9 Coordinated Signal Systems Adaptive signal control technology: Responds to traffic patterns based on current conditions in real time Can change system cycle lengths, phase sequences, or phase lengths on-demand Double serve critical phases Reverts to lower cycle lengths as soon as demand is reduced Requires equipment upgrades Highly configurable, but comes with a learning curve to tweak parameters

10 Adaptive Signal Control Technology Why Mt. Juliet Road? Prior coordination was utilized with time-based coordination/offsets No master controller and no communications Need for improved coordination between signals that would adapt to changing traffic patterns to reduce corridor congestion Fluctuations in traffic patterns daily, weekly, and seasonally Adaptive signal control technology was identified as the primary alternate

11 Mt. Juliet Road Corridor Why not signals to the north (Weston Dr.) and south (Central Pike)? Signal spacing to next signals are 2,700+ ft Average corridor signal spacing is less than 1,000 ft School zone to the north City recently took over maintenance of the signal at Central Pike Central Pike signal in need of upgrades

12 Project Process

13 Project Process Followed typical TDOT Local Programs process (STP funding) Systems Engineering Analysis required Adaptive signal control system Purchase equipment Install Tune Signal upgrades were necessary outside of adaptive equipment Controller upgrades Safety upgrades Detection upgrades

14 Project Process Implementation and construction components: Implementation: RFQ for adaptive system Hardware, software, support, training, field adjustments Construction contract: Installation of all system upgrades, adaptive hardware, wiring, etc. Operation of all equipment

15 Project Process Selected InSync from Rhythm Engineering as the adaptive signal vendor Competitively bid for construction Cost for 8 signals: InSync: $321, ($40k per signal) Includes cameras, in-cabinet equipment, & 5-year support Stansell Electric: $490, Includes $262, for Wavetronix Total: $811,743.50

16 System Components

17 System Components Field: Wavetronix radar detection (stop bar detection) Rhythm cameras (queue and delay detection) Flashing yellow arrows for safety Infinet wireless communication Signal to signal Directional between project and City Hall 16-channel cabinets City Hall: Central server (remote connectivity)

18 System Components Cabinet: McCain ATC ex2 Controller EDI 16 Channel MMU Wavetronix Detection Equipment Rhythm Engineering CPU &Intercept Module Infinet Wireless Comm

19 S. Mt. Juliet Road Looking North

20 InSync Adaptive System Operation

21 How does it work? Detection Inputs Optimizes Sends to Controller Picks non-conflicting phase pair

22 InSync CentralSync Software Tunnel/Coord Time Local Optimization Cycle/Period Length

23 InSync Cycle/period length is dynamic based on real-time demand Serves all coordinated movements Serves all occupied phases at least once per period Length increases when all phases aren t served sufficiently Tunnel/green bands: progression between intersections Local optimization: Serves non-coordinated movements with highest demand Calculated based on queues and delays

24 CentralSync Software

25 Results Throughput on Mt. Juliet Road working very well Added 20 seconds of green time to signals north and south Improvements (preliminary): 60% reduction in # of stops 24% reduction in travel time (1 min) 47% reduction in delay 33% increase in speed (18-24 MPH)

26 Good, Bad, & Beyond

27 Good, Bad, & Beyond Dramatic improvement in initial system operation Final travel time runs pending improvement of communication issues and system tweaks Overwhelming positive response from the community Questions and education necessary for flashing yellow arrows Only one or two negative complaints on side street delays Process of fine-tuning of system parameters Advanced data collection & analysis Counts collected from Rhythm equipment but more accurate counts necessary

28 Good, Bad, & Beyond Improve communications interruptions Future project to install fiber optic communications Local processors still run each signal adaptively if comm is interrupted Powerful tool with a learning curve for the local agency Support available from Rhythm helps with low staffing Advanced signal operations won t take vehicles off the road; additional capacity planned System can adapt for temporary lane closures/traffic control Potential for additional signals added to system

29 Questions? Remember: you re not IN traffic, you ARE traffic. -My Wife