This piece was originally published in the May/June 2019 issue of electroindustry.

Caption | Connected vehicles can help prevent crashes at busy intersections. Photo courtesy of U.S. Department of Transportation

With the advent of connected and autonomous vehicles, NTCIP 1202 v03 Object Definitions for Actuated Signal Controllers (ASC) Interface provides a Standardized way to exchange data so that traffic control systems respond effectively to the presence or absence of one or more vehicles or pedestrians at an intersection.

A revision of NTCIP 1202 v02 (circa 2005), NTCIP 1202 v03 also Standardizes the data exchange between an ASC and a roadside unit, which is a field device serving as an interface to connected and autonomous vehicles.

At an intersection, an ASC coordinates traffic phases that permit vehicles and pedestrians to efficiently use an intersection and avoid collisions. An example of a traffic phase is “permit vehicles  to turn right,” while displaying “Don’t Walk” to pedestrians in the conflicting crosswalk. Based on the number of vehicles and pedestrians wishing to pass through an intersection, the ASC may extend or decrease the amount of time a traffic “phase” is active. ASCs can reduce traffic congestion and its associated effects, such as delays, emissions, and unnecessary fuel consumption, while effectively coordinating vehicle, pedestrian, bicycle, and emergency vehicle flows.

NTCIP is a family of data protocol Standards that specifies commands and data formats for communication between a Traffic Management Center (TMC) and field devices (such as traffic signal controllers at an intersection). In cooperation with the U.S. Department of Transportation, NEMA (and its Transportation Management Systems Members), AASHTO, and ITE founded NTCIP in 1993. For further information, see www.ntcip.org. ei