a planned widening project on Market Street to four lanes between 63rd Street and 44th Street. In addition to the new Elevated structure, all of the stations (including Millbourne) were again replaced with new stations having higher boarding platforms and elevators, allowing customers with disabilities to easily board and depart from trains. The reconstruction of the Market St. Elevated superstructure was completed in 2008, and the last station, 63rd Street, was completed and reopened on May 4, 2009. The Market St. Elevated is not of the same design as the Frankford Elevated, so it does not share any of the Frankford design flaws. In 2003, the Bridge-Pratt terminal was closed and replaced with the new Frankford Transportation Center. After Bridge-Pratt closed, the station platforms and the remaining unrebuilt elevated structure above Frankford Avenue and Bridge Street were demolished. The new $160 million Frankford terminal facility was built on a tract of land off Frankford Avenue formerly part of the adjacent bus and trackless trolley service depot. In November 2011, the Federal Transit Administration (FTA), through its competitive Fiscal Year 2011 Sustainability Initiative, awarded $1.4 million to SEPTA to install a "wayside energy storage system" on the Market–Frankford Line. The system stores energy from braking trains in a battery that may be used later. Extension proposal An extension of the Market–Frankford Line from Frankford to Roosevelt Boulevard and Bustleton Avenue had been proposed in 2011, but no plans or extension construction has taken place. Proposed infill station In the City of Philadelphia's 2021 Transit Plan, one proposal in their list of possible high-capacity transit expansion plans was an infill station located between the MFL's 15th Street and 30th Street stations. The 15-block area between the two stations was cited as being a major part of Philadelphia's CBD since the 1960's. The plan stated that an infill station on the Market-Frankford Line in this part of the city would not only provide better access for major developments, but it would also create transfer opportunities with frequent north-south bus routes on 19th and 20th Streets. However, the 2021 Transit Plan said that while initial studies showed such a station would be feasible and highly beneficial, it would very difficult and expensive to build. Recent developments The line operated "Lifeline Service" due to the COVID-19 pandemic, with trains bypassing , , , , , , , , and stations as of April 2020. All