TOareaFan
Superstar
Right, so it's an even greater difference in capacity then between full buses & full cars.
I would imagine that any comparison of various modes of transport's "capacity" would be based on "how many people could you move on any given street if they were the only mode on the street" So comparing the space that a typical vehicle takes up is only part of the comparison......as is how fast those could move and how many of them you could move through in a given period of time.
It is not so much a comparison of the capacity of the vehicles in a given space....but the comparison of the capacity of the road if those vehicles/modes were in exclusive use of the roadway.
So one thing that probably works against streetcars (and buses for that matter) is the fact that they have to stop more often than a car on the same road would. While all have to stop at lights and stop signs....only public transit vehicles have to stop to let people on and off at transit stops.
It is a theoretical capacity measure of the road given a theoretical operating environment (ie. exclusively buses/cars/sreetcars).....it probably has very little meaning in real life