Rotating Game Object in Movement Direction on planet with Faux Gravity Unity 3D

Hi all,

I am modeling a bicycle traveling around the globe in 3D space. (see video of what I'm doing here: https://youtu.be/XAKR_LDCCho). The problem is that I cannot figure out how to rotate the bicycle towards the direction it's moving in or towards the next waypoint. I believe the problem is two-fold. In my faux gravity attractor script, I am setting the orientation of the bicycle to upright (i.e. perpendicular to the surface of the earth), however, I am then trying to change the bike's rotation in another script. The second problem (I believe) is that I am trying to rotate in world space, whereas I need to rotate in local space such that it travels along the curvature of the earth and doesn't rotate into the surface. I have been researching all day and trying a bunch of solutions, such as the following with comments on what happens when I use the code:

 //this.transform.rotation = Quaternion.LookRotation(GetComponent<Rigidbody>().velocity, Vector3.up); The program loses its mind and jumps around to all sorts of crazy places with this function.
             //this.transform.rotation = Quaternion.LookRotation(_direction); //This is the closest I have to it working. However, the bicycle leans hard towards the earth and I want it to maintain the upright position.
             //transform.LookAt(_targetPosition, _earth.ReturnBodyUp()); //earth.ReturnBodyUp returns the local y axis of the game object, i.e. Perpendicular to the surface of the earth. With this function, the bike doesn't move at all.
             //this.transform.position = Vector3.RotateTowards(_currentPosition, _targetPosition, 0.01f, 0.0f); //The bike doesn't move at all because (I think), it's trying to rotate into the earth's surface and getting stopped by the collider.

Here is the faux gravity attractor script where I initially set the orientation of the bicycle:

 public class FauxGravityAttractor : MonoBehaviour
 {
     [SerializeField] float _gravity = -20;
     Vector3 _gravityUp;
     Vector3 _bodyUp;
     Vector3 _bodyForward;
     Quaternion _bodyRotationValue;
     public void Attract(Transform body)
     {
         _gravityUp = (body.position - this.transform.position).normalized;
         _bodyUp = body.up;
         _bodyForward = body.forward; //getting the local z axis position. 
 
         body.GetComponent<Rigidbody>().AddForce(_gravityUp * _gravity);
         Quaternion _targetRotation = Quaternion.FromToRotation(_bodyUp, _gravityUp) * body.rotation;
         body.rotation = Quaternion.Slerp(body.rotation, _targetRotation, 50 * Time.deltaTime);
     }
 
     public Quaternion ReturnBodyUp()
     {
         return _bodyRotationValue;
     }
 }

and here is the script I use to move the bicycle along the various waypoints:

 public class TransportPathing : MonoBehaviour
 {
     TripConfig _tripConfig;
     TripSpawner _tripSpawner;
     List<Transform> _wayPoints;
     FauxGravityAttractor _earth;
     private Vector3 _original;
     private int _wayPointsIndex = 0;
     Vector3 _direction;
 
     void Start()
     {
         _tripSpawner = FindObjectOfType<TripSpawner>();
         _wayPoints = _tripConfig.GetWayPoints();
         _original = _wayPoints[_wayPointsIndex].transform.position;
         _earth = FindObjectOfType<FauxGravityAttractor>();
         this.transform.position = _original;
         //_direction = (_wayPoints[_wayPointsIndex].transform.position - this.transform.position).normalized;
     }
 
     void Update()
     {
         MoveTransport();
     }
 
     public void SetTripConfig(TripConfig tripConfigToSet)
     {
         this._tripConfig = tripConfigToSet;
     }
 
     private void MoveTransport()
     {
         if (_wayPointsIndex < _wayPoints.Count)
         {
             var _moveSpeed = _tripConfig.GetMoveSpeed();
             var _targetPosition = _wayPoints[_wayPointsIndex].transform.position;
             var _currentPosition = this.transform.position;
             var _movementThisFrame = _tripConfig.GetMoveSpeed() * Time.deltaTime;
             Vector3 _relativePos = _targetPosition - _currentPosition;
              
 
             this.transform.position = Vector3.MoveTowards(_currentPosition, _targetPosition, _movementThisFrame);
             //this.transform.rotation = Quaternion.LookRotation(GetComponent<Rigidbody>().velocity, Vector3.up); The program loses its mind and jumps around to all sorts of crazy places with this function.
             //this.transform.rotation = Quaternion.LookRotation(_direction); //This is the closest I have to it working. However, the bicycle leans hard towards the earth and I want it to maintain the upright position.
             //transform.LookAt(_targetPosition, _earth.ReturnBodyUp()); //earth.ReturnBodyUp returns the local y axis of the game object, i.e. Perpendicular to the surface of the earth. With this function, the bike doesn't move at all.
             //this.transform.position = Vector3.RotateTowards(_currentPosition, _targetPosition, 0.01f, 0.0f); //The bike doesn't move at all because (I think), it's trying to rotate into the earth's surface and getting stopped by the collider.
             
             if (Vector3.Distance(_currentPosition, _targetPosition) < 0.08)
             {
                 _wayPointsIndex++;
             }
         }
         else
         {
             _tripSpawner.ManageLastWayPoint(true);
             Destroy(this.gameObject);
         }
     }
 }

Any and all insights would be much appreciated. Thanks!