The Traffic Signal Board is a popular magic effect. This model suitable for stage use, working on a different principle, and which can be easily adapted to your individual performing preference. Youtube Video
Effect
There is a rectangle shaped board that seems like traffic light, and
once the magician hides the board on the back, the green spot moves from
one side to the other side. The magician hides the board again, and then
the green spot changes into red color and goes back to the original
position. At this moment, the audience notices that the back side of the
board is doubtful. However, when the magician flips over the board, a
yellow spot appears on the back side. The magician then flips over the
board again and amazingly three red, yellow and green spots are there!!
Materials Needed:
A traffic signal board (there are three holes on both sides, and gimmick
boards inside. A mechanic board-we call it as side A for the green spot
side, and we call side B as the other side).1
* The structure of the gimmick and the secrets ()

1. Inside the A side, there is a green and white color double layered
slide board that has a stopper. This side board is placed on the base
layer (red, yellow and white). When you slide the green board from one
end to the other, you can show only green or red, yellow and green.
2. Inside the B side, there is a white slide board, same as A side, placed
on the base layer (red, yellow and white). When you slide this board to
the red or yellow section, you can show only red or yellow.
3. For the preparation, you slide the boards (A side is only green and B
side is only red).
(In this explanation, right and left green spot is seen from the
audience side)
The gimmick:
1. Red, yellow, white panel is on bottom. Green and white panel slides.
Could show either green and two white panels; or red, green and white
panel; or red, yellow, and green panel
2. Red, yellow, and white panel is on bottom. White center panel slides
to show either red or white spot.
Routine and the way of performing()

1. You show A-side to the spectator and green spot is placed on the left
side. (B-side (red face magician)
2. You hide the board behind back or object and turn up side to down
(CAUTION: Do not move slide board). You show A-side to the audience, so
the green spot moves to the other end.
3. You perform and repeat procedure 2. You look around the spectator and
say Oh! You guys have noticed how it works. OK, then
4. You hide the board behind your back (CAUTION: Do not show B-side to the
spectator). This time, you turn over the board lengthways. You show B-side
and the green spot changes into red.
5. You perform the same thing as is shown 4, so red spot goes back into
green original position. (In this moment, the spectator suspects that
there must be a red spot on the back side of green spot). Then, you
secretly move the slide board that is placed on the middle of B-side by
using your fingertip; also you look around the spectator
6. You say Oh! Back side is shady?. You flip over the board, and show
B-side which is really different from the spectators expectation, because
there is a yellow spot on it. Next, you ask the spectator How do you think
about the back side? and also you do
7. Use your both thumbs, you secretly move A-side of green slide board
from one end to the other end.
8. After the spectators reaction, you slip over the board slowly.
Surprisingly, there are red, yellow and green spots on it. You may modify
routine to fit your style.
Alternative Performance:
1. The performer shows a red spot on the left side and two white spots.
2. He places behind back and the red spot jumps to the right side.
3. Then places behind back and the red spot jumps back to the left side.
4. Audience thinks that the person turns the sign around. On back of the
sign is the green spot. Shows audience.
5. Slide white over red to show the middle yellow spot.
6. Flip to show the yellow spot and green spot facing magician.
7. Slide green / white panel to show red, yellow and green.
8. Show all 3 colors.