Contact Triggered Waypoint

You would just setup a waypoint script that is activated on collision like you describe.

MoveScript.js

var wayPoints : Vector3[] = new Array(); //points to move to var moveToWayPoint : boolean = false; //whether to move to points var startPosition : Vector3; //where we are moving from var speed : float = 0.5; //how fast to move (1/speed seconds to move between points) private var weight : float = 0; //how far we've moved from between points private var wayPoint : int = 0; //the point we're moving to

Update() { if(moveToWayPoint && startPosition) { //moving weight += Time.deltaTime * speed; //update how far if(weight >= 1) { //move to the next point weight -= 1; startPosition = wayPoints[wayPoint]; wayPoint++; } if(wayPoint < wayPoints.Length) { //not at the end, so move transform.position = Vector3.Lerp(startPosition, wayPoints[wayPoint], weight); } else { //at the end, so reset weight = 0; wayPoint = 0; moveToWayPoint = false; } } }

TriggerScript.js

OnTriggerEnter(other : Collider) { //collided so make it move to waypoints
    var script : MoveScript = other.gameObject.GetComponent(MoveScript);
    script.StartPosition = other.transform.position;
    script.moveToWayPoint = true;
}

You could put your waypoints wherever you like or generate them somehow (finding one which is ahead of it? what defines being ahead?).

Because of the poor English, I'm not sure if you meant waypoint (singular) (it should read "...the object is forced along a path to a waypoint..." and "...until it reaches the waypoint?") or waypoints (plural) (it should read "...the object is forced along a path of waypoints..." and "...until it reaches the last waypoint?"), so I went with plural and if you only want one, you can simplify it from there.