Christmas tree (drag racing)

Modern drag races are started electronically by a system known as a Christmas tree. A common Christmas tree consists of a column of seven lights for each driver or lane. Each side of the column of lights is the same; from the top down, there are a blue LED light set (top and bottom halves), then three amber bulbs, then a green bulb and a red bulb. Prior to 2011, the function of the blue light set was performed by four smaller amber bulbs.

The lights are activated after the drivers are properly staged on the starting line by interrupting a set of two light beams across the track itself. One set is on the starting line, and the other set sits 7 in (180 mm) behind it.