Eric Graves, P.E. City Traffic Engineer Alpharetta, Georgia Adaptive Signal Control Technology:  Managing Risks, Achieving Objectives Eric Graves, P.E. City Traffic Engineer Alpharetta, Georgia

Alpharetta Transportation System 50,00 Residents Day Time Population~100,000 ADP HP UPS North Point LCI Downtown LCI

Alpharetta Transportation System 4 Interchanges with GA 400 (Limited Access Freeway) 7, 4-6 Lane Arterial Streets ~ 120 Traffic Signals 3 Emergency Signals at Fire Stations 1 Hawk Signal – April All newer equipment – GDOT ATC Program 332 cabinets 2070 controllers – SEPAC Firmware Ethernet Communications 60% direct connections to City TCC

Traffic Operations 2 Public Works Crews 1 Signal Systems Engineer Signs Signals 1 Signal Systems Engineer 1 Traffic Engineering Technician Inspect Construction Projects Manage maintenance contracts Striping Loop Repairs

Traffic Operations Signal Systems Engineer Signal Timing Maintenance Program Systemic timing of all traffic signals every 2-3 years Before/After travel time measurements Timing reports to be published on the City Web Site (soon)

Why Adaptive?? Less $$ available for capacity improvements Less opportunity for new roadway connections Alpharetta is land locked and nearly built out Essential we operate our system as efficiently as possible Initiative included Systems / Timing Engineer PM Program Timing Maintenance Program

Why Adaptive ?? Traffic STILL a top concern from citizen survey What else can be done??? Cobb County SCATS System Councilman read article on SCATS Success Directed Staff to investigate options for Alpharetta

When Adaptive Makes Sense Unpredictable Traffic Flow High sustained growth Freeway system interactions

When Adaptive Makes Sense Agency Capabilities Technician capabilities Detection at 98%!! Strong communications Fiber along all major corridors Stable Ethernet field network

When Adaptive Makes Sense Agency Capabilities Engineering Staff In-house signal timing maintenance program “One of the best signal timers in the state”

When Adaptive Makes Sense Desire Continuously Optimized Timings!!

Alpharetta Adaptive Signal Evaluation: Hypothesis A well-timed system is a well-timed system Cycle length- appropriate for volume Split percentages- balanced or prioritized Offsets- provide good progression Peak-hour performance on day 365 and 730 should be better than doing nothing Pause for questions

Alpharetta’s Criteria Should be able to perform close to manual optimized timings Maximize the utilization of existing infrastructure 332 cabinets/ 2070 controllers/ SEPAC Firmware Ethernet Communications/ECOMM Optimize Progression on Corridors Provide Queue Management Coordinate crossing arterials?? Manual control?? Special events/Seasonal Peaks/Incidents

Identified Solutions SCATS – Cobb County SCOOT **OFFERED DEMO** ACS Lite InSync **OFFERED DEMO**

Identified Solutions The City of Alpharetta performed demonstration projects with two adaptive platforms InSync and SCOOT The results of the demo projects indicated that adaptive solutions could replicate current timing efforts Potentially improving operations for special events, unexpected events, and off peaks periods

Other Systems Considered SCATS New Firmware New Detection Separate Central System OPAC Distributed solution – more rigorous detection requirements ACS Lite Presently not available in TACTICS Presently does not optimize cycle length

Next Steps SR 9 18 mile corridor Sandy Springs Roswell Alpharetta GDOT 18 mile corridor Collector between outer suburbs and GA 400 interchanges Primary arterial (Sandy Springs/Roswell) Back up for GA 400 PM Team identified Adaptive as an ITS Strategy

SR 9 ATMS Project PM Team initially considered performance Spec FHWA/GDOT indicated that as written only one vender likely fulfilled requirements FHWA determined documentation was insufficient to sole source

SR 9 ATMS Project GDOT/FHWA Required PM Team to follow Federal Regulations mandating System Engineering Process to select Adaptive Solution

SR 9 ATMS Project Systems Engineering Report completed and accepted by FHWA Systems Engineering Process identified similar functional requirements as the Alpharetta demo projects SCOOT determined as preferred option Compatible hardware with jurisdiction platform Ability to coordinate with non-adaptive intersections using Tactics Central System

SR 9 ATMS Project Project recently received NTP!!

egraves@alpharetta.ga.us eveith@alpharetta.ga.us Questions?? egraves@alpharetta.ga.us eveith@alpharetta.ga.us