發送短信 : Traffic light control for multi-junctions

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    ___    |  ___|| | \  / || | || | ||  |__  //  
   /   ||  | ||__   |  \/  || | || | ||    / //   
  | [] ||  | ||__   | .  . || | \\_/ ||   / //__  
   \__ ||  |_____|| |_|\/|_||  \____//   /_____|| 
    -|_||  `-----`  `-`  `-`    `---`    `-----`  
     `-`