void OnCollisionEnter(Collision collisionInfo)
 {
     if (collisionInfo.collider.gameObject.CompareTag("Traffic"))
     {
         generator = pathMap.GetComponent <RandomTrafficGenerate> ();
         generator.currentTrafficNumber = generator.currentTrafficNumber - 1;
         Destroy(gameObject);
     }
 }
    void UpdateWheelSteer()
    {
        Vector3 steerVector = transform.InverseTransformPoint(new Vector3(
                                                                  pathPoints [currentPathPoint].position.x,
                                                                  transform.position.y,
                                                                  pathPoints [currentPathPoint].position.z));

        wheels[0].steerAngle = maxTurn * (steerVector.x / steerVector.magnitude);
        wheels[1].steerAngle = maxTurn * (steerVector.x / steerVector.magnitude);

        if (steerVector.magnitude <= distanceFromPoint)
        {
            currentPathPoint++;
            if (currentPathPoint >= pathPoints.Count)
            {
                generator = pathMap.GetComponent <RandomTrafficGenerate> ();
                generator.currentTrafficNumber = generator.currentTrafficNumber - 1;
                Destroy(gameObject);
            }
        }
    }