An alternative I thought up a while ago, but would require quite intelligent smart traffic lights, is a form of TSP where if a streetcar is behind left turning cars, to give the cars an advanced left to clear out of the way of the streetcar. And the advanced left would only be triggered by a streetcar near the intersection, to not slow down streetcars going the other direction unncessecarily. Basically the purpose of the advanced left would be only for the purpose of getting the left turning cars out of the path of a streetcar.