T4 (SEPTA Metro)

The T4, formerly Route 11, is a light rail line operated by the Southeastern Pennsylvania Transportation Authority (SEPTA) that connects the 13th Street station in Center City, Philadelphia, to Darby Transit Center in Darby, Pennsylvania. It is one of five T services of the SEPTA Metro. Sitting at an average of 13,580 riders per weekday in 2019, it is the most used T service.

Starting from its eastern end at 13th Street, the T4 runs in a tunnel under Market Street. It stops at underground stations at 15th Street/City Hall, 19th Street, 22nd Street, Drexel Station at 30th Street, and 33rd Street. From 15th to 30th Streets, it runs on the outer tracks of Market Street subway, beside the L.

Passengers may transfer free of charge to the L at 13th Street, 15th Street/City Hall, and Drexel Station at 30th Street and to the B at 15th Street/City Hall. Connections to SEPTA Regional Rail are also available. Underground passageways connect the 13th and 15th Street/City Hall stations to Jefferson Station and Suburban Station.

The T4 surfaces at the 40th Street Portal near 40th Street and Baltimore Avenue (US 13), and then runs southwest along Woodland Avenue, along with the T5. At 49th Street, the T5 splits and heads south. The T4 continues its run along Woodland Avenue. The line runs parallel to the north side of the Wilmington/Newark Line and crosses a bridge over CSX's Philadelphia Subdivision freight line, at 60th Street.

At the intersection of Island Road and the Cobbs Creek Parkway, a track runs southward toward 73rd–Elmwood station on the corner of Elmwood Avenue. The T4 moves northwest from Woodland Avenue to Main Street as it crosses the Cobbs Creek and enters Darby. Here, the T4 crosses the Philadelphia Subdivision again, but at an at-grade crossing along with 6th Street.^[2] The road and line move to the west shortly, only to turn back northwest and finally north to 9th Street at the Darby Transit Center.

What is now the T4 was first established as the West Philadelphia Passenger Railway Company in Darby on December 24, 1858, and ran as horsecars from 9th and Main Streets in Darby to 49th Street and Woodland Avenue in West Philadelphia. It was originally a segregated streetcar that required African-Americans to ride on platforms along with the driver, until abolitionist William Still challenged that rule between 1859 and 1867.^[3] In 1896, the line was extended as far east as Front Street via Chestnut and Walnut Streets, and was integrated into the subway–surface trolley system by the Philadelphia Rapid Transit Company on December 15, 1906.^[4] The original numbered designation was "Route 11".

The at-grade crossing along Main Street at the intersection of Sixth Street in Darby^[5] was the site of the Darby Baltimore and Ohio Railroad station. B&O had passenger service into Philadelphia until 1958.^[6]

On December 9, 2021, a T4 LRV collided with a CSX Transportation freight train operating on the Philadelphia Subdivision at the at-grade crossing between the two lines near the intersection of Main Street and Sixth Street in Darby. Seven people on the LRV were injured, and the front windshield was smashed.^[7] All of the people injured in the crash were treated and released from the hospital on the same day.^[8] This is reportedly the only remaining intersection in the nation where an active freight rail line crosses a fixed active rail transit line.^[9]

Route 11 was renamed as the T4 on February 24, 2025.^[10]

All are in either the city of Philadelphia or the borough of Darby.

• Official T4 schedule
• Subway-Surface Lines & Proposals on Google Maps