Presentation in SPaT Challenge Webinar Series Webinar #9: Operational SPaT Deployments.
Atlanta, Georgia, United States
This presentation provided an update of Georgia DOT (GDOT) Operational SPaT (Signal Phase and Timing) Deployments implemented as part of the nationwide SPaT Challenge sponsored by AASHTO. The initiative challenges state and local public sector transportation infrastructure owners and operators (IOOs) to deploy DSRC (dedicated short-range communications) enabled infrastructure with SPaT/MAP (Signal Phase and Timing and Map data) broadcasts in at least one corridor or network (approximately 20 signalized intersections) in each state by January 2020.
The GDOT system focused on safety, mobility, freight, and partnerships. A primary goal was to develop back-end infrastructure, network components, and business processes to support broad vehicle to infrastructure applications that were broadcast-medium agnostic, scalable, and sustainable. A secondary goal was to begin broad installation of roadside units (RSUs) and equipped vehicles to enable applications that improve safety and mobility.
Active deployments as of June 2018 are located in urban areas inside the I-285 beltway north of downtown Atlanta.
Phase 1 of the project included the use of wireless DSRC as a medium to support the following SPaT applications:
- Red light warning: Safety for drivers – alerts of inability to safely clear intersection
- Pedestrian in crosswalk: Safety for drivers and pedestrians – turning vehicles have additional awareness of other users
- Phase service remaining: Efficiency for drivers – alerts drivers for safe intersection passage or efficient stopping
- Green speed for coordinated signals: Efficiency for drivers – informs drivers of the optimal driving speed through coordinated signals to minimize stops
DSRC SPaT and MAP messages are exchanged between intersection systems, connected vehicles, and pedestrians with connected devices.
RSUs broadcast SPaT and MAP messages to provide current signal status (color) by lane and the geometric layout of an intersection. RSUs require a connection to signal controllers, and signal controllers must provide the required data.
SPaT and MAP messaging were tested in Atlanta to assess performance of design elements (Communications, ATC Signal Controllers, and DSRC Radios) and conformance to standards such as SAE J2735 prior to broad deployment in Georgia.
The first 250 RSUs were expected to be deployed by the end of 2018.
Phase 2 of the project (2019 – June 2020) will expand the scope of the system to include the following systems and functional components to connect 1,700 traffic signals in metro Atlanta.
- 185 ramp meter locations
- Safety applications
- Signal applications
- Red light warning
- Pedestrian in signalized crosswalk
- Phase termination/next signal phase
- Green-band speed
- Road and traffic conditions information
The proposed system will enable connectivity on every major arterial in metro Atlanta and provide an Open Data Stream to third parties. The following data excerpted from the source report show cost estimates for three major cost drivers through FY2020.
| PHASE 2 DEPLOYMENT ESTIMATE | FY 2019 (600 RSUs) | FY 2020 (1100 RSUs) |
|---|---|---|
| RSU Equipment | $780,000 | $1,430,000 |
| RSU Deployment | $510,000 | $935,000 |
| RSU Configuration & Support | $1,200,000 | $2,200,000 |
| TOTAL | $2,490,000 | $4,565,000 |
- 1,700 Roadside units at $1,300 per device.
- RSU deployment at $850 per location.
- RSU configuration at $2,000 per device.
- OBU costs at $1,000 per device (optional).
Georgia DOT Statewide Connected Vehicles Deployment Experience and Future Plans (Presentation)
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