diff --git a/src/roadveh_cmd.cpp b/src/roadveh_cmd.cpp
--- a/src/roadveh_cmd.cpp
+++ b/src/roadveh_cmd.cpp
@@ -163,7 +163,7 @@ void DrawRoadVehEngine(int left, int rig
 static uint GetRoadVehLength(const RoadVehicle *v)
 {
 	const Engine *e = v->GetEngine();
-	uint length = e->u.road.shorten_factor;
+	uint length = VEHICLE_LENGTH;
 
 	uint16 veh_len = CALLBACK_FAILED;
 	if (e->GetGRF() != NULL && e->GetGRF()->grf_version >= 8) {
@@ -173,7 +173,8 @@ static uint GetRoadVehLength(const RoadV
 		/* Use callback 11 */
 		veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, v->engine_type, v);
 	}
-	if (veh_len != CALLBACK_FAILED) {
+	if (veh_len == CALLBACK_FAILED) veh_len = e->u.road.shorten_factor;
+	if (veh_len != 0) {
 		if (veh_len >= VEHICLE_LENGTH) ErrorUnknownCallbackResult(e->GetGRFID(), CBID_VEHICLE_LENGTH, veh_len);
 		length -= Clamp(veh_len, 0, VEHICLE_LENGTH - 1);
 	}