Toyota to test in-car traffic signal alert intelligent transport system

  • Encouraging early deceleration can help reduce CO2 emissions
  • Cooperative vehicle-infrastructure systems can contribute to reducing traffic accidents

Toyota Motor Corporation (TMC) announced that it will conduct public road tests of a Toyota-developed driving support system using ITS (1) technology to transmit information from traffic light signals information to vehicles, starting in May, 2013 in Toyota City, Japan. The system is part of a number of Driving Safety Support Systems (DSSS) being promoted by the Japanese National Police Agency and sponsored by the Universal Traffic Management Society of Japan (UTMS Japan) (2).

One road in Toyota City will be used for the tests which will be equipped with a system to transmit traffic light signal information to vehicles through its on-board testing equipment using the 700 MHz bandwidth (3). The system receives the information, providing alerts when necessary to vehicle occupants via the audio system and on-screen on the navigation system. Added to TMC's separate system to help drivers notice red lights, it is hoped that by early encouragement to decelerate when approaching red lights, the system can help in reducing CO2 emissions.

Provision of traffic light signal information was made possible with the cooperation of the National Police Agency and the Aichi Prefectural Police.

Through these tests, TMC will analyse driver behaviour under various driving conditions to understand the extent to which cooperative vehicle-infrastructure systems can contribute to reducing traffic accidents and CO2 emissions, and incorporate the data into future ITS development.

Based on its Integrated Safety Management Concept, TMC is making proactive efforts to develop its driving vehicle infrastructure cooperative (4) safety support systems utilising ITS technologies that make it possible to connect people, vehicles, and traffic environments. TMC has been using the 700 MHz band (allocated by the Japanese government for ITS) starting with road tests in March last year on a support system aimed at preventing collisions caused by driver error during right-hand turns at intersections.


(1) Intelligent Transport Systems: systems that seek to prevent traffic accidents by alerting the driver to dangerous situations through provision of visual and aural information on nearby traffic conditions, reduce environmental impact and emissions, and create a more comfortable driving environment.

(2) Carries out surveys, research, and development on Universal Traffic Management Systems (UTMS). UTMS Japan aims to contribute to social welfare by promoting more intelligent road transportation ensuring safe, smooth road transportation and ensuring harmony with the environment.

(3) 700 MHz band ITS standard (ARIB STD-T109). Because this communication method features electromagnetic waves with excellent propagation characteristics, it is expected to be effective for supporting the prevention of vehicle-to-vehicle collisions at intersections and collisions with vehicles coming from the opposite direction when making right-hand turns.

(4) A type of ITS that receives information — including traffic regulation information (such as information on the cycle of traffic lights) and information about things that cannot be directly seen by the driver — via wireless communication from communications infrastructure installed in roads and other vehicles. By notifying the driver of this information, this system supports safe driving and helps prevent accidents.