DSRC and SPaT, SSM, SRM & MAP Co-operative ITS and SCATS Updated 30/03/2015

Co-Operative Intelligent Transport Systems (C-ITS) Co-Operative ITS Emerging technology to enable vehicles and infrastructure to exchange information about location, speed, direction, status, etc. Vehicle-to-Infrastructure (V2I) Vehicles to Road Side Units communication (i.e. traffic controllers) Receive traffic signal information based on vehicle’s position and direction of movement Provide vehicle data (speed, direction, length) to RSUs to improve traffic management (i.e. queue detection) Vehicle-to-Vehicle (V2V) Improve vehicle “awareness” Collision warning systems Benefits: Improve road safety and reduce congestion by aiding drivers in making better decisions when behind the wheel

C-ITS in Australia C-ITS continued… Vehicles with built-in C-ITS: expected to arrive in 2015 CITI Project First permanent test facility to evaluate benefits and risks associated with the technology SCATS Provide traffic signal information Receive vehicle data as an input to be used in improving traffic management functionality Red-light violation warning

Co-Operative Intelligent Transport Systems (C-ITS) Theoretical C-ITS system view VEHICLE INFRASTRUCTURE INTEGRATION (VII), CONCEPT OF OPERATIONS, US Dept of Transport Federal Highway Admin. Sep 2006, V1.2

DSRC, SPaT and Map Messages Dedicated Short Range Communications Designed specifically for automotive use 5.9 GHz Band (75Mhz spectrum US, EU uses 30MHz) EU, USA and JAP systems are currently incompatible SPaT – collection of four messages - SAE J2735 standard SPaT: Signal Phase and Timing – provides the intersection’s signal light phases MAP: Map Data – provides the physical geometry of the intersection SRM: Signal Request Message – requests preempt or priority services SSM: Signal Status Message – information about the internal state of the controller

Signal Phase and Timing (SPaT) What is SPaT? Intersection status message Message data: Intersection state Movement state Lane set - (i.e. lanes 9-10 are for movement state 1) Current state - (Green, Yellow, Red, Flashing, Off) Time until current signal state changes

Purpose of MAP message Message data Map Data (MAP) Geometric layout of intersection Message data Reference point (intersection centre) Number of approaches Lane number Lane width Lane attributes Straight, Left, Right, Turn on Red, Bus, etc... Offsets Points along each lane - used to detect vehicle position

Signal Request Message (SRM) SPaT and Map messages – Intersection-to-Vehicle (I2V) SRM – Vehicle-to-Intersection (V2I) Priority signal request or a pre-emption signal request Vehicle identifies itself using Vehicle Identification Number Provides current position data (speed, heading, vehicle size, etc.)

Signal Status Message (SSM) Signal Status Message – related to SRM Provides current intersection status to all vehicles in range Active and pending priority and pre-emption requests Allows other users to see their ranking/position in queue for any requests made as well as view currently active requests Message Data Status of signal controller Active priority requests Source of priority (which vehicle sent request) Active pre-emption requests Source of pre-emption (which vehicle sent request) SSM message dependent on current request status If no active events, SSM message is not broadcasted

Basic Safety Message (BSM) Purpose of BSM Exchange safety data regarding vehicle state V2I & V2V applications Message data Position (lat, long, elevation, accuracy) Motion (speed, heading, wheel angle, acceleration) Vehicle size Vehicle status (lights, wipers, brakes, sensors, etc) 10

SCATS C-ITS Phase I Project A trial to evaluate the SPaT and MAP messages Aim: To display current traffic signal status in vehicles Interface 1: TSC <-> DSRC radio provides data to form SPaT messages Interface 2: Geometry Server <-> DSRC radio provides Map information ITS Summit 2013: www.youtube.com/watch?v=wznpUv2PucQ

SCATS C-ITS Phase I Project ITS Summit 2013: www.youtube.com/watch?v=wznpUv2PucQ 12

SCATS & the CITI Project Cooperative ITS Initiative Project Transport for NSW’s Centre for Road Safety to provide the first permanent test facility for C-ITS Heavy Vehicle Trial route: Port Kembla to F6 Freeway SCATS Provide SPaT and MAP messages Advanced Driver Warning system Transport for NSW - Project Proposal Report for Hume Highway to Port Kembla Corridor, CITI project (under HVSPP Round 3), John Wall, 22/10/2012 Version 0.7.3

SCATS & the CITI Project continued… Transmission of SPaT messages

SCATS C-ITS Phase II and beyond Adaptive Traffic Signals challenge Countdown can only be provided during the intergreen period Only reliable green time that can be provided is minimum green interval, not sufficient for Advanced Driver Warning system Investigate the impact on adaptive traffic management of allocating a guaranteed green time interval during which signal group cannot terminate x secs SG cannot terminate Exact signal timing known Signal timing subject to change, within max/min values

SCATS C-ITS Phase II and beyond Vehicle-to-intersection communication Signal Request Message Pre-emption and Priority services (Ambulance, Fire, Police) Basic Safety Message Vehicle position, speed, type and length information could be used to implement queue detection 16

Truck signal change warning Future Applications Truck signal change warning Driver warning of an impending traffic signal change such that deceleration can be planned in order to stop safely at the intersection Transit vehicle signal priority Traffic signal priority request from public transport vehicles Emergency vehicle alerts Vehicles are alerted to the presence of an emergency vehicle approaching the intersection, which is given traffic signal priority Red light violation alert A warning indication is provided to the driver that a red light violation is likely to occur

Questions? QUESTIONS?