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1 The Technology Side of the Sydney Coordinated Adaptive Traffic System (SCATS) Presented by: Betsy Williams TransCore.

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Presentation on theme: "1 The Technology Side of the Sydney Coordinated Adaptive Traffic System (SCATS) Presented by: Betsy Williams TransCore."— Presentation transcript:

1 1 The Technology Side of the Sydney Coordinated Adaptive Traffic System (SCATS) Presented by: Betsy Williams TransCore

2 2 SCATS Background The Roads and Traffic Authority of New South Wales (RTA) Developer and primary user of SCATS Continued innovation through user group involvement Extensive user base Effective, mature, practical system Worldwide - over 21,000 intersections under SCATS control in 71 installations

3 3 Shenyang Tianjin Shanghai, Ningbo Suzhou Hangzhou Guangzhou Hong Kong Manila Cebu Kuala Lumpur Seremban Singapore Brunei Sandakan Jakarta Bandung Detroit Delaware Durham Cobb Co Suva Fiji Shijuazhuang Tehran Mashhad Dublin Auckland Wellington Christchurch + 11 cities Darwin Perth Adelaide Sydney Melbourne & many other cities Mexico City Toluca SCATS Worldwide System Installations Yichang Doha Chula Vista Pasco Co. Concepcion Gresham Park City Menlo Park Sunnyvale Waterford Israel Yanbu Dacca Hanoi Pattaya Vietianne Rzeszow Pietermaritzburg

4 4 SCATS US Installations

5 5 Benefits of SCATS Reduces need/effort for updating signal timing Accommodates traffic fluctuations Allow special functions to be installed for event centers Assist maintenance of signals via monitoring features Collect volume counts for planning purposes

6 6 Typical Adaptive vs. TOD Graph

7 7 SCATS Objectives Select cycle length, splits and offsets to achieve Minimum stops with light demand Minimum delay with normal demand Maximum throughput with heavy demand

8 8 SCATS Detection

9 9 SCATS Detection Requirements YES Stop bar NO Advanced Upstream Downstream Mid-block

10 10 SCATS Detector Requirements Presence detection Optimal strategic SCATS detectors are 6 ft x 15 ft located at the stop line for all lanes Detectors can be longer or shorter if needed, however shorter is better than longer Local actuation detectors may be used at minor intersections and can be varying in size

11 11 Typical Detector Layout

12 12 SCATS operates by looking at space between vehicles Eliminates vehicle length from equation Graph is linear with no double curves Loop Space Time (secs) SCATS Detectors

13 13 SCATS Equipment

14 14 SCATS Controllers SCATS uses 2070 controllers 2070 Lite – no VME backplane Eagle and Econolite 2070s 2070N – reuse of existing cabinets Eagle M-50 series 170 E controllers SafeTran or McCain controllers

15 15 Hardware Requirements Server Requirements Minimum 400 MHz Intel processor – 128M RAM Windows NT or 2000 Laptop and Workstation Requirements Minimum 400 MHz Intel processor – 128M RAM Windows NT, XP or 2000 Dial-in access 56K modem VPN access

16 16 Communications Leased line, twisted pair copper, fiber optic, spread spectrum radio 300 bps per controller Point-to-point communication Point-to-multipoint communication Ethernet/IP communications

17 17 SCATS Operation

18 18 SCATS Modes Adaptive Mode Traffic adaptive coordination mode Time-of-Day Mode Fixed-time coordination fallback mode Free Mode Vehicle actuated operation Master Free Mode Vehicle actuated with SCATS calculated splits Flash

19 19 SCATS GUI Familiar Windows interface Pull down menus Real-time information

20 20 Active Time-Space Monitor

21 21 Reports

22 22

23 23 For additional information contact: Betsy Williams TransCore (770) or Travis White TransCore (801)

24 24

25 25 Proven Performance Chula Vista, CA Travel Time Reduced By Up To 15% Travel Speed Increased By Up To 18% Delay Reduced By Up To 43% Menlo Park, CA Stops Reduced By Up To 24% Travel Time Reduced By Up To 28% Delay Reduced By Up To 44%

26 26 Proven Performance Road Commission For Oakland County, Michigan Corridor Travel-Time Reduction Range 6.56% To 31.8% Average Travel-Time Improvement 7.8% For Peak Traffic During Peak Periods Broward County, Florida Stops Reduced By Up To 28% Travel Time Reduced By Up To 20% Delay Reduced By Up To 42%

27 27 Automatically calculated to try to maintain Degree of Saturation between 80% and 90% on the lane with the highest DS Lower and upper limits are user definable (20 secs to 190 secs) Can vary by up to 21 seconds per cycle – usually only 2 to 5 seconds SCATS Functions - CYCLE LENGTH

28 28 Varied automatically by up to 4% each cycle. Tries to maintain equal Degree of Saturation on competing approaches. Minimums are user definable. Maximums are limited by cycle length and minimum requirements of other phases. SCATS Functions - SPLITS

29 29 SS 1 SS 2 SS 3 SYSTEM Intersections can "marry" or "divorce " with each other Married intersections operate on a common cycle length (and offset plan) Intersections marry: when their CL's are within 10 sec or when one-way volume exceeds a configured threshold or when a forced / continuous marriage is required SCATS Functions - Linking

30 30 The best offsets are selected for the high flow movements. Preset offset plans automatically vary to compensate for varying cycle lengths. Directional bias based on measured flows. SCATS Functions – OFFSETS

31 31 Intersection Display Currently activated detectors shown blue. Shown red if faulty

32 32 Alarm Display All operator actions and alarms can be sorted, filtered and printed

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