it visible from both the interior and exterior. A similar, smaller sign is mounted over car-end doors when cab equipment is present; this sign is only visible from the exterior. These signs were a significant improvement over earlier rolling stock which completely lacked such signage. Each sign consists of a set of 12 panels arranged in 4 rows of 3 columns each (a 3 x 4 grid). Each panel can be illuminated by an incandescent light bulb. As shown above, the upper three rows indicate station names while the bottom row indicates type of service. Trains normally light three panels: two station names (origin and destination) and a type of service (local, express, or special). Only significant stations are represented in the grid. In 1982, following delivery of the first significant number of B-IV cars, SEPTA assigned these cars to the restoration of express service. The signs were lit to show "OLNEY" "WALNUT" "EXPRESS". In early 1983, with more B-IV cars arriving and placed into local service, signs showed "FERN ROCK" "PATTISON" "LOCAL". After delivery of the last cars, Broad–Ridge Spur trains showed "ERIE" "8th-MARKET" (rush hour) or "GIRARD" "8th-MARKET" (off-peak and weekends). Special trains showed "FERN ROCK" "PATTISON" "SPECIAL" "EXPRESS". Subsequent changes to express and Broad–Ridge Spur service patterns led to the current signage: express trains show "FERN ROCK" "WALNUT" "EXPRESS" and Broad–Ridge trains show "OLNEY" "8th-MARKET" "EXPRESS" (weekdays) and "FERN ROCK" "8th-MARKET" "EXPRESS" (weekends). In 2010, with the renaming of the terminal, all signs were updated with "AT&T" in place of "PATTISON", and again with "NRG" replacing "AT&T" in 2018. Operating times and headways A local trip along the entire line takes about 35 minutes. Trains run from approximately 5:00 am to 1:00 am, with a timed-transfer at 12:30 am at City Hall station to connect with the Market Frankford Line based on final trains. The Broad Street Owl bus service replaces the subway throughout the night Monday through Friday mornings, stopping at the same locations as the subway trains. The line itself ran 24 hours a day until it was eliminated in 1991; it was reinstated on June 20, 2014 for Friday and Saturday overnights only on a trial basis. It was made permanent on October 8, 2014 due to the line successfully carrying an extra 10,000 riders on the Broad Street Line during the weekend overnight periods. This was eliminated again in 2020 due to the