Editing Traffic light (section)

==== Countdown lights ====
Popular in Vietnam and China, countdown lights are additional lights installed next to, or above or below, the main signal lights. The countdown light is displayed by a countdown number with different colors, usually red, yellow, green, matching the color of the light on. When the light counts to "0" (or 1), the main light color immediately changes. 

Countdown lights may have zeros in the tens or none, some countdown lights may flash when getting ready to zero. Yellow lights can have countdown lights, but most lights do not. Usually the countdown light has 2 digits, in case the time of the main light (usually the red light, rarely the green light) is longer than 100 seconds, depending on the type of light, the following possibilities may occur:

# Lights have not counted down, when 99 seconds are left, start counting. During the standby time, the light may be displayed as "99", "00", "--" or not displayed.
# Last 2 digits count light of the timeout (the counter light is 15 while the time is 115 seconds, there are some types of lights that count as "-9" or "9-" when the time is 109 seconds)
# Tens digit on the displayer becomes a letter. Displaying A0 for 100 seconds, B0 for 110 seconds, so forth.
# Displaying only last 2 digits but with flashing to indicate it's more than 100.
[[File:CountDownTrafficLight.gif|thumb|125px|A countdown light]]