A further eight trains, tentatively numbered 312-08~312-15, are expected to be manufactured and delivered before 2023. Older Class 311000 trains were overhauled from 2004 to 2006 (though minor refurbishments began in 2002). Major and minor refurbishments are listed below. The Daegu subway fire compelled Korail to introduce flame-resistant interiors for passenger safety. As a result, all trains built before 2004 were overhauled with fire-retardant interiors. All 1st generation trains and some 2nd generation trains used an old KNR green (and yellow for the 1st generation trains) livery. These trains were repainted into the current blue and red livery in 2006. The new livery has a metaphor of Taegeuk, but was criticized as being too primitive-looking. Livery is applied only on front and on the doors. Since August 2008, all trains were retrofitted with automatic gangway doors (similar retrofits were also done in Class 321000, 341000, and 351000 trains). This retrofit included the installation of automatic doors to replace the older doors that were manually pulled open; gangway doors can now be automatically opened by the push of a button. This retrofit process was completed by 2013. All trains are now being retrofitted with LED headlights, following the successful testing of LED headlights in trains 311-75 and 311-92~311-94. Starting from March 2011, former Class 5000 trains were renumbered from the 5000-series to the 311000-series as a part of a new numbering scheme by Korail (the leading "3" indicating a metro car). Renumbering was finished in September 2011. Many former Class 5000 trains were not renumbered into the 311000-series and were instead converted into other classes. After it was discovered that the Yeongdungpo-Gwangmyeong shuttle service on Line 1 had a relatively low ridership, it was decided to cut down the number of cars on trains dedicated to the shuttle service. As a result, seven trains, numbered 319-01~319-07 were formed using out-of-service cars and surplus trains. Trains 319-01~319-05 were formed from parts of former Class 5000 trains 5-79~5-80 and 5-86~5-92. Meanwhile, trains 319-06~319-07 were formed from the eight remaining cars from former Class 5000 train 5-19. The gangways and interiors were refurbished as the cars were being converted and rearranged.