List of United States rapid transit systems by ridership
The following is a list of all heavy rail rapid transit systems in the United States. It does not include statistics for bus or light rail systems (see: List of United States light rail systems by ridership for the latter).

List of United States rapid transit systems by ridership

Section Title:
Table Section Text: The following is a list of all heavy rail rapid transit systems in the United States. It does not include statistics for bus or light rail systems (see: List of United States light rail systems by ridership for the latter).

System	Transit agency	City/Area served	Annual ridership (2017)	Avg. weekday ridership (Q4 2017)	System length	Rider. per mile	Opened	Stations	Lines

1.	New York City Subway	New York City Transit Authority	New York City	2,699,536,300	8,852,200	245 miles (394 km)	36,131	1904	472	27

2.	Chicago "L"	Chicago Transit Authority	Chicago	230,204,200	729,200	102.8 miles (165.4 km)	7,093	1892	146	8

3.	Washington Metro	Washington Metropolitan Area Transit Authority	Washington, D.C.	229,595,700	760,200	117 miles (188 km)	6,497	1976	91	6

4.	MBTA Subway ("The T") (Blue, Orange, and Red Lines)	Massachusetts Bay Transportation Authority	Boston	167,167,900	457,994	38 miles (61 km)	12,052	1901	53	3

5.	Bay Area Rapid Transit (BART)	Bay Area Rapid Transit District	San Francisco Bay Area	129,268,100	432,900	112 miles (180 km)	3,865	1972	46	5

6.	PATH	Port Authority of New York and New Jersey	Manhattan; Hudson County, and Newark	93,012,400	315,600	13.8 miles (22.2 km)	22,870	1908	13	4

7.	SEPTA (Broad Street, Market–Frankford, and Norristown High Speed Lines)	Southeastern Pennsylvania Transportation Authority	Philadelphia	91,772,000	348,600	36.7 miles (59.1 km)	9,499	1907	75	3

8.	MARTA Rail Transit	Metropolitan Atlanta Rapid Transit Authority	Atlanta	67,410,000	213,200	47.6 miles (76.6 km)	4,479	1979	38	4

9.	Metro Rail (Purple and Red Lines)	Los Angeles County Metropolitan Transportation Authority	Los Angeles	44,860,700	138,500	17.4 miles (28.0 km)	7,960	1993	16	2

10.	Metrorail	Miami-Dade Transit	Miami	19,680,400	66,700	24.4 miles (39.3 km)	2,734	1984	23	2

11.	PATCO Speedline	Port Authority Transit Corporation	Philadelphia, southern New Jersey	10,839,100	38,100	14.2 miles (22.9 km)	2,683	1936	13	1

12.	Baltimore Metro Subway	Maryland Transit Administration	Baltimore	10,821,100	29,647	15.5 miles (24.9 km)	1,719	1983	14	1

13.	Staten Island Railway	Staten Island Rapid Transit Operating Authority (SIRTOA)	Staten Island (New York City)	8,768,600	33,800	14 miles (23 km)	2,414	1860	22	1

14.	RTA Rapid Transit (Red Line)	Greater Cleveland Regional Transit Authority	Cleveland	5,904,200	19,176	19 miles (31 km)	926	1955	18	1

15.	Tren Urbano	Autoridad de Transporte Integrado	San Juan	4,834,500	13,245	10.7 miles (17.2 km)	1,238	2004	16	1

Sentence(s)

Boston's public transportation agency, the Massachusetts Bay Transportation Authority (MBTA) is the fourth-busiest rapid transit system.

final_sentence: Boston's public transportation agency, the Massachusetts Bay Transportation Authority (MBTA) is the fourth-busiest rapid transit system.