Plus...it seems to me that the Metro is the only way to get a full crowd into and out of a game. Cars carry let's guess two people. If 15,000 people travel by car, that's an extra 7500 cars going to and from a single spot. All need parking.
More: I took the Metro to Navy Yard the last two games we saw. Before the game, a near sellout against the Braves, the crowd streaming up the escalator jammed against the crowd trying to get out the station doors. People were coming off the top of the escalator faster than the crowd got out of the station. It was only luck that someone didn't fall backward from the top of thje escalator, carrying everyone back on top of people riding up.
The station needs wider doors, more escalators, maybe even some wide stairways.
The baseball crowds won;t get smaller, and Metro is the best way to and from Nats Park.