Arduino [or other uCPU] controlled.....

/*
  Traffic
  Cycles through 2 banks of Red-Yellow-Green LEDs to simulate a traffic signal for model railroading.
  M. Markham 1-27-13
 
  This example code is in the public domain.
 */

// Define the pins that will drive the signal
const unsigned int REDW =     2;    // West - Primary Direction
const unsigned int YELLOWW =  3;
const unsigned int GREENW =   4;
const unsigned int REDN =     5;    // North - Secondary Direction
const unsigned int YELLOWN =  6;
const unsigned int GREENN =   7;
const unsigned int TICK = 500;      // Cycle clock


// the setup routine runs once when you press reset:
void setup() {                
  // initialize the digital pins as an outputs.
  pinMode(REDW,OUTPUT);   
  pinMode(YELLOWW,OUTPUT);
  pinMode(GREENW,OUTPUT);
  pinMode(REDN,OUTPUT);
  pinMode(YELLOWN,OUTPUT); 
  pinMode(GREENN,OUTPUT);
  // Initialize all pins with red signal in both directions
  digitalWrite(REDW,HIGH);   
  digitalWrite(YELLOWW,LOW);
  digitalWrite(GREENW,LOW);
  digitalWrite(REDN,HIGH);
  digitalWrite(YELLOWN,LOW); 
  digitalWrite(GREENN,LOW);
       
  
  
}

// the loop routine runs over and over again forever:
void loop() {
  digitalWrite(GREENW, HIGH);    // turn the wesr green LED on red off
  digitalWrite(REDW,LOW);
  delay(5 * TICK);               // wait 
  digitalWrite(YELLOWW, HIGH);   // turn the yellow LED on green off
  digitalWrite(GREENW,LOW);
  delay(2 * TICK);               // wait 
  digitalWrite(REDW, HIGH);      // turn the yellow LED off red on
  digitalWrite(YELLOWW,LOW);
  delay(TICK);                    // short wait to present all red
  digitalWrite(GREENN, HIGH);    // Cycle north direction
  digitalWrite(REDN,LOW);
  delay(5 * TICK);               // wait 
  digitalWrite(YELLOWN, HIGH);   // turn the yellow LED on green off
  digitalWrite(GREENN,LOW);
  delay(2 * TICK);               // wait 
  digitalWrite(REDN, HIGH);      // turn the yellow LED off red on
  digitalWrite(YELLOWW,LOW); 
  delay(TICK);                   // wait 
  // Ready to start the loop again  
}

int led = 13;

const unsigned int led = 13;

#define led 13