You're in charge of programming the traffic lights in the city! It's a busy place, so try not to cause traffic jams, or more importantly, any accidents. When you succeed, try to cut down on the timing to get a better score!

Your code is saved automatically.

The levels

• The tutorial level: Simple enough. Just merge two one-way roads onto another shared one-way road.
• Level 1: A classic 4-way road. Autonomous cars can't tell when to make discretionary left turns though, so you'll have to guide them.
• Level 2: A big road connecting into a small road. The small road's traffic ranges from nothing to quite a decent bit of traffic, so you'll have some induction pads to detect when cars are on the small road.

Sample code

loop:
// 0 goes first
green 0
wait 3
// make 0 red, then wait for intersection to clear
red 0
wait 1
// 1 goes second
green 1
wait 3
// wait for intersection to clear again
red 1
wait 1
// repeat
goto loop

Command reference

GREEN X... -> Sets traffic light X and more to green
RED X... -> Sets traffic light X and more to red
GREENLEFT X -> Sets traffic light X's left arrow to green
GREENRIGHT X... -> Sets traffic light X's right arrow to green
REDLEFT X... -> Sets traffic light X's left arrow to red
REDRIGHT X... -> Sets traffic light X's right arrow to red
CLEARLEFT X... -> Sets traffic light X's left arrow to nothing
CLEARRIGHT X... -> Sets traffic light X's right arrow to nothing
X: -> Represents a label X for GOTO (no instructions on the same line for now)
GOTO X -> Jumps execution to label X
WAIT X -> Waits X seconds
SET X Y -> Sets variable X to a number
ADD X Y -> Adds variable X to a number.
READ X Y -> Sets variable X to induction sensor Y (1 = has car, 0 = no car)
IFNEG X Y -> Jumps to label Y if variable X is negative
IFPOS X Y -> Jumps to label Y if variable X is positive