The Breda trains were so noisy that San Francisco budgeted over $15 million to quiet them down, while estimates range up to $1 million per car to remedy the excessive noise. To this day, the Breda cars are noisier than the PCC or Boeing cars. In 1998, NTSB inspectors mandated a lower speed limit of , down from , because the brakes were problematic. The ATC system was plagued by numerous glitches when first implemented, initially causing significantly more harm than good. Common occurrences included sending trains down the wrong tracks, and, more often, inappropriately applying emergency braking. Eventually the result was a spectacular service crisis, widely referred to as the "Muni meltdown", in the summer of 1998. During this period, two reporters for the "San Francisco Chronicle"—one riding in the Muni Metro tunnel and one on foot on the surface—held a race through downtown, with the walking reporter emerging the winner. After initial problems with the ATC were fixed, substantial upgrades to the entire Muni transit systems have gone a long way towards resolving persistent crowding and scheduling issues. Nonetheless, Muni remains one of the slowest urban transport systems in the United States. In 1980, the M Ocean View was extended from Broad Street and Plymouth Avenue to its current terminus at Balboa Park. In 1991, the J Church was extended from Church and 30th Streets to its current terminus at Balboa Park. In 1998, the N Judah was extended from Embarcadero Station to the planned site of the new Pacific Bell Park and Caltrain Depot, after that extension was briefly served between January and August of that year by the temporary E Embarcadero light rail shuttle (restored in 2015 as the E Embarcadero heritage streetcar line). In 2007, the T Third Street, running south from Caltrain Depot along Third Street to the southern edge of the city, opened as part of the Third Street Light Rail Project. Limited weekend T line service began on January 13, 2007, while full service began on April 7, 2007. The line initially ran from the southern terminus at Bayshore Boulevard and Sunnydale Street to Castro Street Station in the north. The line ran into initial problems with breakdowns, bottlenecks, and power failures, creating massive delays. Service changes to address complaints with the introduction of the T Third Street were implemented on June 30, 2007, when the K and T trains were interlined, or effectively merged into one single line with route designations changing at the entrances into the subway (T becomes K outbound at Embarcadero; K becomes T inbound at West Portal).