Maryland State Highway Authority (MSHA)
The Signal Phase and Timing (SPaT) Challenge was a Cooperative Automated Transportation (CAT) Coalition (led by AASHTO, ITE, and ITS America, with support from the AASHTO Connected and Automated Vehicle Working Group) initiative that encouraged state and local public sector transportation infrastructure owners and operators to achieve deployment of DSRC/C-V2X infrastructure with SPaT broadcasts in at least one corridor or roadway network (approximately 20 signalized intersections) in each of the 50 states. The main purpose of the challenge program was to provide SPaT and geographic intersection description information to motorized and non-motorized road users through a connected transportation system. A SPaT message defines the current intersection signal phases and can come from a traffic signal controller via a standard query protocol. Most DSRC/C-V2X roadside devices broadcast it as a standardized data message. This is a critical enabling capability for future Connected and Automated Vehicle (CAV) traffic management.
As part of this project, Econolite Systems, Inc. (ESI) implemented a turnkey Connected Vehicle (CV) deployment for 20 intersections along US Highway 1 and MD 175 in Howard County, Maryland, which fulfilled the requirements of AASHTO’s Signal Phase and Timing (SPaT) Challenge. The project included the initial design and implementation of the SCMS for Maryland DOT. Additionally, ESI in coordination with MSHA performed an evaluation of CV RSU/OBU vendors and determined the optimal deployment of dual-mode CV technology to achieve the project scope and provide a foundation for future CV deployments. ESI furnished and installed 20 Commsignia dual-mode CV Road-Side Units (RSUs) and five CV On-Board Units (OBUs). The project scope also included project design; CV equipment installation and configuration; Security Credential Management System (SCMS) initialization and configuration; and integration with existing traffic signal control and communications equipment.