because of increased patronage in the 1990s. As I-95 was built through Center City Philadelphia in the late 1970s, part of the Frankford El was relocated to I-95's median, and the Fairmount station was replaced by Spring Garden, on May 16, 1977. Skip-stop operation, which was only available during rush hours on weekdays, was discontinued on February 21, 2020. Reconstruction Between 1988 and 2003, SEPTA undertook a $493.3 million complete reconstruction of the Frankford side of the Market–Frankford Line between Frankford Transportation Center and the 2nd Street portal. The new Frankford Elevated was built with new stringers and deck installed on the original columns, thus giving not only a reduction in cost, but also reducing the street-level impact on adjoining neighborhoods. The old ballasted trackage was replaced with a direct fixation system. In addition to the new Elevated structure, all of the stations were replaced with new stations with higher boarding platforms and elevators, allowing customers with disabilities to easily board and depart from Market-Frankford trains. The reconstruction of the Frankford Elevated structure was mostly complete by 2000, with the exception of the elevated section from Dyre Street (just to the south of the Bridge-Pratt terminal) to the Frankford Yard entrance. The basic design of the bearings of the reconstructed Frankford elevated, however, was not appropriate for the repetitive loading from the train traffic. The bearing design did not take into consideration the interaction of the concrete haunches with the steel stringers when loaded by the passing train; and the concrete has started to fracture and drop onto the street below. The problem was first discovered in 1997, but at that time was simply attributed to faulty construction, without evaluation of the root cause. As a temporary fix, SEPTA has installed 10,000 metal mesh belts on the underside of the structure. Estimates for a permanent fix placed the cost at about $20 million, and SEPTA has filed suit against the engineering companies that contributed to the design flaw to recover part of the repair cost. Work on the permanent fix is currently underway. SEPTA then undertook a $567 million complete reconstruction of the Market Street Elevated between 69th Street Transportation Center and the 44th Street portal between 1999 and 2009. The New Market Street Elevated was an entirely new structure, utilizing single-pillar supports in place of the old-style dual pillar design, allowing the Pennsylvania Department of Transportation (PennDOT) to undertake