Adaptive Signal Control in Atlanta District. Rebecca Wells, P.E. TxDOT Atlanta

Transcription

1 Adaptive Signal Control in Atlanta District Rebecca Wells, P.E. TxDOT Atlanta

2 Why Adaptive Control Typical corridor has timing plan Time of Day Days of week changes School, annual special events, etc. Works okay, Signal technicians are reactive to problems

3 Striving for Excellence Reduce travel time Increase efficiency of corridor Reduce delay Proactive operations

4 Traditional Upkeep Periodically retime corridors Difficult for District Staff to have resources to do with our personnel $1500 to $3500 per intersection to retime Temporary benefit Lack of funding for consultant work

5 Various adaptive control systems Real time adaptive control Reacts to the traffic as it happens, adjusts timing to best serve, real time traffic Responsive adaptive control Evaluates what is happening at the intersection over several cycles, and adjusts timing over a period of time

6 Various systems Several minor players, but don t have many deployments SCOOT SCATS InSync ACSLite

7 SCOOT Avg installation cost per intersection $30,000 to $60,000 About 25 hours per intersection to install Avg 13 hours per week per intersection maintenance time Approx 13% time downtime

8 SCOOT Proprietary controller Specific detectors required Handles up to 255 intersections Can work with grid system

9 SCATS Avg installation cost per intersection $30,000 to $60,000 About 13 hours per intersection to install Avg 8 hours per week per intersection maintenance time Approx 4% down time

10 SCATS benefits Limited types of controller can be used Specific detector required Handle 250 intersections Linear Arterial only

11 InSync Avg installation cost per intersection $25,000 to $35,000 About 19 hours per intersection to install Avg 5 hours per week per intersection maintenance time Approx 2% down time

12 InSync Proprietary controllers required Specific cameras required Linear arterial only

13 InSync HDR 2010 survey -most felt system met or exceeded their expectations for reducing overall delay, decreasing number of stops, or improving the overall travel time Issues with communications and detection At times, registers false positives and misses calls

14 InSync Video detection and communications a concern for most survey respondents Greatest improvement during peak period travel times Only Real Time Adaptive Traffic Control

15 ACS Lite Avg installation cost per intersection $12,000 to $38,000 About 7 hours per intersection to install Avg 6 hours per week per intersection maintenance time Approx 9% downtime

16 ACS Lite Variety of controllers (NTCIP) Flexible on type of detectors 16 intersection or 32 intersections depending upon communication availability Linear arterial only

17 ACS Lite HDR Most felt the system met or exceeded their expectations of decreasing arterial delay, decreasing number of stops, reducing intersection delay Does not work in a grid patter Does not work well with short duration high volume peak

18 ACS Lite Overall ACS lite is the least labor intensive for installation and fine tuning Issues with communications most common problem Designed to be low-risk approach to ASCT Developed with public/private partnership (FHWA)

19 What does it do? ACS Lite Balance Utilization of Green Adjusts Splits balances demands across all phases Adjusts Offsets monitors changing speeds of platoons and system throughput

20 City of Marshall

21 US 59 AADT 27,000 US 80 AADT 15,900 Major US Route Tourism Industry Recreation

22 City of Marshall

23 Typical System Architecture varies depending upon communications and setup

24 Detector Placement any type of detectors Stop bar detectors for all approaches - Cameras Need advance detectors for platoons on main arterial Wavetronix RADD

25 Optimize the phase utilization

26 ACS Lite Keeps controller s timing as standard Downloads new splits and offsets for the currently running pattern every five to fifteen minutes, maintaining the same cycle length for that time of day.

27 Does it work? Measure of Effectiveness and Performance Evaluation Smooth flow on arterial, two-way progression Manage queues Manage side street flows Prevent or delay oversaturation Reduce variance

28 Flow Profile Displays date per detector for each approach Percent greens (green), occupancy (blue), and capture (black) Works to maximum capture

29 Pattern History

30 Split Adjustments

31 Marshall, Tx CSJ Special Spec Bid Item $90,000 Contract Start Jan Working Days Project ends early Dec

32 Marshall, Tx Has redlight running equipment Installed RADDs poles to see platoons Cellular modem

33 Marshall, Tx One Master at US US 80 3 additional intersections connected 6 more intersection to include

34 Marshall, Tx Upgrade controllers Install detection devices Install modems

35 Adaptive Signal Control Adaptive Traffic Control Signals will not replace the need for signal technicians, but should help fine tune an operable system