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.
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.
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.
Time and speed are recorded at five intervals along the track.
There are clocking devices at the 60-foot, 330-foot, 1/8-mile, 1,000-foot and 1/4-mile
Speed Traps and Elapsed-Time Clock Beams:
The first of these infrared beam
sender/receiver triggers is located 66 feet before the finish line and is used to start
the individual lane top speed clocks. A second beam, located at the finish line, shuts
off both the individual lane elapsed-time and top speed clocks, and triggers the win
indicator. The 66-foot speed trap computes top speed.
The length of the actual racing surface at an NHRA Drag Racing Series event is
one-quarter mile, or 1,320 feet. The average width of each lane is 30 feet.