Transport Department - Electronic Audible Traffic Signal

Electronic Audible Traffic Signal

1. Introduction

The function of electronic audible traffic signals (eATS) is to provide indication to the visually impaired persons (VIP) on the prevailing pedestrian signals. The eATS currently installed on street is capable of responding automatically to the ambient noise level. Its output is automatically higher under noisy environment and lower if the environment is quiet. The eATS can provide clear audio messages to the VIP while minimizing the noise nuisance to the nearby residents. The eATS is also equipped with a tactile unit which indicates the prevailing pedestrian signal states by means of different vibrating patterns.

2. Existing eATS

The eATS comprises :-

(i)	Audible unit; and
(ii)	Tactile unit with or without push button function

Audible unit, mounted under pedestrian signal lights, emits audible signal to indicate the prevailing pedestrian signal states.
Tactile unit is a yellow box mounted at elbow level of the pedestrian signal pole with a vibrator located at the bottom of the unit. The vibrator provides different vibrating patterns to indicate the prevailing state of pedestrian signals. There is also a directional arrow indicating the direction of the pedestrian crossing for the use of VIP. If the tactile unit at the crossing has no pedestrian push button function, the "green man" signal will automatically appear according to pre-determined sequence and time.


Existing tactile unit	Existing vibrator and directional arrow

Some pedestrian crossings^# have tactile units equipped with a pedestrian push button function, which are for the use by all pedestrians, not just for VIP. When a pedestrian presses the button, the unit will provide visual and audible acknowledgement messages, and the traffic signal controller will issue a green pedestrian signal as quickly as possible.

_{# At some crossings with high vehicle flow and relatively low pedestrian traffic, green pedestrian signal will only be activated after the pedestrian push button is pressed, allowing more vehicles to pass through the junction.}


Existing tactile unit with pedestrian push button function

3. New generation eATS

Starting in 2025, the Transport Department gradually renews existing eATS at all pedestrian crossings in Hong Kong. Apart from retaining the existing functions, the following five new features have been added to the new eATS:

(i)	Light Illumination Unit - A light illumination unit is installed at the top of the new eATS, making it easier for persons with amblyopia to locate the pedestrian crossing;
(ii)	Tactile Map - A tactile map is provided on the side of the eATS, providing layout information of the vicinity of the pedestrian crossing to the VIP;
(iii)	Voice Message of Crossing Location - The new eATS has a voice message reading function. By pressing the activation button located at the bottom, the device will read out the names of nearby streets to inform users of their location;
(iv)	Touchless Pedestrian Push Button - A touchless pedestrian push button sensor is provided below the light illumination unit on the front of the new eATS, allowing pedestrians to activate the button without contact, reducing hygiene concerns of users; and
(v)	Flexible Volume Adjustment - The device features a new nighttime operation mode. When there is no VIP seeking to cross the road at night, the operating volume of the eATS will be lower than the existing level, thus reducing impact on nearby residences*. VIP can use a newly designed dedicated wireless device or mobile application to temporarily increase the volume of the eATS when they need to cross the road, ensuring their safe crossing.

_{* Depending on the specific location's environment and needs, the typical volume of the new eATS in night mode can be further reduced by up to 5 decibels as compared to the existing eATS.}

New generation eATS

Audible Unit

Tactile unit without pedestrian push button function (Grey panels)	Tactile unit with pedestrian push button function (Blue panels)