Of the united states subways systems /stations

AtlantaMARTA1979387748BaltimoreMetro Subway19831424.515.2BostonMBTA[note 19][53][54]1897516138ChicagoChicago 'L'1897[note 20][55]145173107ClevelandRTA Rapid Transit (Red Line)1955183119Los AngelesLos Angeles County Metro Rail[note 21][56]19931628.017.4MiamiMetrorail19842340.124.9New York CityNew York City Subway[note 22][57][58][59]1904421337209New York CityStaten Island Railway1925[note 23]2222.514.0New York City/New JerseyPATH1908[60]1322.213.8PhiladelphiaSEPTA[note 24]19075338.523.9Philadelphia/New JerseyPATCO Speedline19361322.914.2San Francisco Bay AreaBART[61]197244167104San JuanTren Urbano20041617.210.7Washington, D.C.Washington Metro197686171106

which ones do you have to pay to uses ?

 

Never mind at least for the New york and Boston subways they are all pay for.

But curious if one of the above is free in the US. Or all the subway stations you have to pay ?

Also curious which one is the cheapest probably the one that needs little maintainces or staff. Which would also be a direct corolation with the least mileage stations / routes.