Add RoadManager with a road generation script

scripts/road_manager.gd

@@ -0,0 +1,54 @@
+extends Node3D
+
+@export var player: CharacterBody3D
+@export var spawn_distance: float = 100.0
+@export var despawn_distance: float = 200.0
+
+var road_scene = preload("res://scenes/road.tscn")
+var roads = []
+var road_length: float
+
+func _ready():
+	# Calculate road length from existing instance
+	var temp_road = road_scene.instantiate()
+	# Get the MeshInstance3D from the road scene structure
+	var mesh_instance = temp_road.get_node("RoadObject") as MeshInstance3D
+	if mesh_instance:
+		var aabb = mesh_instance.mesh.get_aabb()
+		road_length = aabb.size.x * mesh_instance.scale.x
+	else:
+		push_error("Could not find RoadObject MeshInstance3D in road scene")
+		road_length = 20.0  # Fallback value
+	temp_road.queue_free()
+	
+	# Initialize with existing road
+	var initial_road = $Road
+	roads.append(initial_road)
+
+func _process(delta):
+	if not player:
+		return
+	
+	var player_x = player.global_position.x
+	
+	# Spawn new roads ahead
+	var last_road = roads[-1]
+	var last_road_end = last_road.global_position.x + road_length
+	if player_x + spawn_distance > last_road_end:
+		spawn_road(last_road_end)
+	
+	# Despawn old roads behind
+	for road in roads.duplicate():
+		var road_end = road.global_position.x + road_length
+		if player_x - road_end > despawn_distance:
+			despawn_road(road)
+
+func spawn_road(position_x: float):
+	var new_road = road_scene.instantiate()
+	new_road.global_position = Vector3(position_x, 0, 0)
+	add_child(new_road)
+	roads.append(new_road)
+
+func despawn_road(road: Node3D):
+	road.queue_free()
+	roads.erase(road)