I should offer full disclosure here and say that there are no streetcar tracks on my everyday commuting route. However I've ridden this intersection at night in the rain a few times without incident (and without big veer-right-then-left maneuvers).

A 2.5" MTB tire at moderate pressure is enough to bridge the rail on those tracks, i.e. even if you are riding right along the rail, the edges of the tire will be on concrete.

That's an observation, not a suggested course of action.

Its not the most efficient setup for rolling resistance, but neither is putting on studded tires and rolling through two inches of packed slush.