diff --git a/src/rail_gui.cpp b/src/rail_gui.cpp
index 0177547305..4dd7d39ada 100644
--- a/src/rail_gui.cpp
+++ b/src/rail_gui.cpp
@@ -438,8 +438,8 @@ struct BuildRailToolbarWindow : Window {
 
 	BuildRailToolbarWindow(WindowDesc &desc, RailType railtype) : Window(desc)
 	{
+		this->railtype = railtype;
 		this->CreateNestedTree();
-		this->SetupRailToolbar(railtype);
 		this->FinishInitNested(TRANSPORT_RAIL);
 		this->DisableWidget(WID_RAT_REMOVE);
 		this->OnInvalidateData();
@@ -490,16 +490,10 @@ struct BuildRailToolbarWindow : Window {
 		return true;
 	}
 
-	/**
-	 * Configures the rail toolbar for railtype given
-	 * @param railtype the railtype to display
-	 */
-	void SetupRailToolbar(RailType railtype)
+	void OnInit() override
 	{
-		this->railtype = railtype;
-		const RailTypeInfo *rti = GetRailTypeInfo(railtype);
-
-		assert(railtype < RAILTYPE_END);
+		/* Configure the rail toolbar for the railtype. */
+		const RailTypeInfo *rti = GetRailTypeInfo(this->railtype);
 		this->GetWidget<NWidgetCore>(WID_RAT_BUILD_NS)->widget_data     = rti->gui_sprites.build_ns_rail;
 		this->GetWidget<NWidgetCore>(WID_RAT_BUILD_X)->widget_data      = rti->gui_sprites.build_x_rail;
 		this->GetWidget<NWidgetCore>(WID_RAT_BUILD_EW)->widget_data     = rti->gui_sprites.build_ew_rail;
@@ -516,7 +510,7 @@ struct BuildRailToolbarWindow : Window {
 	 */
 	void ModifyRailType(RailType railtype)
 	{
-		this->SetupRailToolbar(railtype);
+		this->railtype = railtype;
 		this->ReInit();
 	}
 
diff --git a/src/road_gui.cpp b/src/road_gui.cpp
index c5bb6d8d50..db299a53ad 100644
--- a/src/road_gui.cpp
+++ b/src/road_gui.cpp
@@ -347,9 +347,8 @@ struct BuildRoadToolbarWindow : Window {
 
 	BuildRoadToolbarWindow(WindowDesc &desc, WindowNumber window_number) : Window(desc)
 	{
-		this->Initialize(_cur_roadtype);
+		this->roadtype = _cur_roadtype;
 		this->CreateNestedTree();
-		this->SetupRoadToolbar();
 		this->FinishInitNested(window_number);
 		this->SetWidgetDisabledState(WID_ROT_REMOVE, true);
 
@@ -409,18 +408,9 @@ struct BuildRoadToolbarWindow : Window {
 		}
 	}
 
-	void Initialize(RoadType roadtype)
-	{
-		assert(roadtype < ROADTYPE_END);
-		this->roadtype = roadtype;
-	}
-
-	/**
-	 * Configures the road toolbar for roadtype given
-	 * @param roadtype the roadtype to display
-	 */
-	void SetupRoadToolbar()
+	void OnInit() override
 	{
+		/* Configure the road toolbar for the roadtype. */
 		const RoadTypeInfo *rti = GetRoadTypeInfo(this->roadtype);
 		this->GetWidget<NWidgetCore>(WID_ROT_ROAD_X)->widget_data = rti->gui_sprites.build_x_road;
 		this->GetWidget<NWidgetCore>(WID_ROT_ROAD_Y)->widget_data = rti->gui_sprites.build_y_road;
@@ -438,8 +428,7 @@ struct BuildRoadToolbarWindow : Window {
 	 */
 	void ModifyRoadType(RoadType roadtype)
 	{
-		this->Initialize(roadtype);
-		this->SetupRoadToolbar();
+		this->roadtype = roadtype;
 		this->ReInit();
 	}