NHRA National Event 'Christmas Tree' Starting Line System

FULL TREE: Used in Competition, Super Stock and Stock, for which a handicap starting system is used to equalize competition. The three amber bulbs on the Christmas Tree flash consecutively five-tenths of a second apart, followed five-tenths later by the green starting light. A perfect reaction time on a full Tree is .000.

PRE-STAGE INDICATOR LIGHTS: Yellow bulbs warn drivers that they are approaching the starting line and the "staged" position.

STAGE INDICATOR LIGHTS: Signal drivers that they are on the starting line and ready for a run. These yellow bulbs come on when the front wheels of the race car interrupt the beam from a light source to the photo cells. These same photo cells start the timing equipment.

THREE AMBER STARTING SYSTEM: All three amber floodlights in a driver's lane flash simultaneously before the green light comes on. This is called a "pro start" system. Racers running in handicap categories get a countdown of one amber light at a time until the green light comes on. The "pro start" system runs with a .4-second difference between the amber and green lights, while the handicap system runs with a .5-second difference between bulbs. Many non-national event tracks still use a five-amber light.

GREEN LIGHT: This is the one that makes it all happen. Once the green light is flashed, the driver in that lane is free to make a run down the track. Any time green light is shown in a driver's lane it indicates that a fair start was accomplished.

RED LIGHT: When a car leaves the starting line before the green light comes on, or, in some cases, is staged too deeply into the staging beams, the red light will flash in that lane. It indicates the driver in that lane has been disqualified. During competition, only one red light will light, thus eliminating only the first offender.