Unlimitted run Game on mobile.

I'm working on mobile game it's a car moving automatically and the player just move it left and right by touch screen my question is how can I add or modify on my script below to make car just moving in three lanes as player touch like temple run and subway surfer .Also, when I tested my script I found problems in touch to move car left and right...how to say go or not to go right and left and how to determine 3 lanes also i need to know why my script not working perfectly...please help i'm lost in this give me an example don't let me like this I spent severa days in this without any benefit result.

          public var position: Vector2;
             var rotate : float = .2;
           function Update () {
 
         transform.Translate(Vector3.forward * Time.deltaTime*30);
 
             if (Input.touchCount > 0 && 
    Input.GetTouch(0).phase == TouchPhase.Moved)
    
  {  var touchDeltaPosition:Vector2 = Input.GetTouch(0).deltaPosition;
       
        
            transform.Rotate (0,touchDeltaPosition.y*rotate , 0);
                           touchDeltaPosition = position;}
    
                if (Input.GetKey("escape")) {
                     Application.Quit();}}