traffic signals / traffic signals

The existing traffic lights transmit signals through colors. They are designed to transmit the intuitive signal system to general people, but they can't transmit any signal to those who are color-blind or color-weak. However, those who distinguish signals and pass the exam for a driver's license can drive a car.Drivers who are color-blind or color-weak memorize signals and distinguish them through the difference in brightness, which is very dangerous and inconvenient for them. Now those who are color-blind and color-weak can recognize a signal through a shape as well as brightness so signals can be transmitted more safely.