Temple run game

I have to make for school a simple temple run game and I just need some help with coding. I need ideas how to generate a terrain that goes straight forward, right, left and with T-split.

Here is some code I made so far:

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class World : MonoBehaviour {
     
     enum Directions {
         Straight = 0,
         Left = 1,
         Right = 2,
         Tsplit = 3
     }
     
     public Transform prefab, prefab2;
     public static float pre1;
     public int numberOfObjects;
     private Vector3 nextPosition;
     private float recycleOffset;
     private Queue<Transform> objectQueue;
     private int direction;
     
     private float numberObjects = 0;
     private bool switchDirection = true;
 
     void Start () {
         recycleOffset = prefab.localScale.x + prefab.localScale.z;
         direction = 0; // onthoud dit
         nextPosition = transform.localPosition;
     }
 
     void Update () {
         
         pre1 = nextPosition.x;
         Debug.Log(pre1);
     if(nextPosition.x - recycleOffset < Player.distanceTraveled.x){
             
             switch(direction)
             {
                 case (int)Directions.Straight:
                     Straight();
                 break;
                 
                 case (int)Directions.Left:
                     Left();
                 break;
                 
                 case (int)Directions.Right:
                     Right();
                 break;
                 
                 case (int)Directions.Tsplit:
                     // T-splitsing
                 break;    
             }
         }    
     }
 
     private void Straight () { // Dit is 0
         Debug.Log(direction + "Straight");
         numberObjects += 1;
         Vector3 position = nextPosition;
         for (int i = 0; i < numberOfObjects; i++) {
             Instantiate(prefab, nextPosition, prefab.rotation);    
             nextPosition += new Vector3(
              prefab.localScale.x, 0,0);
             
             if(numberObjects == i && switchDirection) {
                 switchDirection = false;
                 numberObjects = 0;
                 direction = Random.Range(1, 3);
             }
         }
         
         Instantiate(prefab2, nextPosition, prefab.rotation);
     }
     
     private void Left () { // Dit is 1
         Debug.Log(direction + "Left");
         numberObjects += 1;
         Vector3 position = nextPosition;
         
         for (int i = 0; i < numberOfObjects; i++) {
             Instantiate(prefab, nextPosition, prefab.rotation);
             
             nextPosition += new Vector3(
              0, 0, -prefab.localScale.x);
             
             if(numberObjects == i && !switchDirection) {
                 switchDirection = false;
                 numberObjects = 0;
                 direction = 0;
                 
                 if (direction == 0) {
                     switchDirection = true;    
                 }
             }
         }
         
         Instantiate(prefab2, nextPosition, prefab.rotation);
     }
     
     private void Right () { // Dit is 2
         Debug.Log(direction + "Right");
         numberObjects += 1;
         Vector3 position = nextPosition;
         
         for (int i = 0; i < numberOfObjects; i++) {
             Instantiate(prefab, nextPosition, prefab.rotation);
             
             nextPosition += new Vector3(
              0, 0, prefab.localScale.x);
             
             if(numberObjects == i && !switchDirection) {
                 switchDirection = false;
                 numberObjects = 0;
                 direction = 0;
                 
                 if (direction == 0) {
                     switchDirection = true;    
                 }
             }
         }
         
         Instantiate(prefab2, nextPosition, prefab.rotation);
     } 
 }

This piece of code is to generate a terrain based on the x value of the player. When the x value is greater then the nextPostion (this is written inside the script World) then it randomly generates a next terrain, this can be right, left or T-split.

Right now I got code to generate a terrain to left, right and straight forward. But how can I implement a T-split in code and when a T-split is generated that it builds further on which direction the player choosed. It sounds all complex but I think is it all quiet simple but I can't come with it right so I really need some help for this school project.

Any code or tips are helpfull,

Thanks in advance.