Line 6 (Guangzhou Metro)

Route

What would become Line 6 first appeared in the Guangzhou Fast Rail Transit Network Design Report in 1997. It proposed a Line 7 starting from Sanyanqiao near Jiaokou, running along the north bank of the Pearl River, then turning sharp north for an interchange with Line 1 at Martyrs' Park, then northeast out of the city centre to Gaotangshi.^[5]

By 2003, the western end of the plan had been rearranged, with Line 5 now heading to Jiaokou, and Line 6 moved further north to terminate on Jinshazhou Island. The interchange with Line 1 had also been moved one stop down to Dongshankou.^[5]

Line 6's Environmental Impact Assessment received approval on 13 July 2006.^[6] The route was confirmed in a government announcement in December that year, running 31.3 kilometres (19.4 mi) from Xunfenggang to Gaotangshi with 26 stations in total (identical to the current route). A depot would be constructed on Jinshazhou island, with a stabling yard in Kemulang at the other end of the line (ultimately not constructed). It was expected to be completed in 2010.^[7]

A further east extension from Changban to Xiangxue was announced in 2009. By now, the first stage announced in 2006 had been truncated to Changban, with Changban to Gaotangshi now part of the extension. Accordingly, the proposed stabling yard at Kemulang was replaced with one in Luogang district.^[8]

Construction

Huangsha was chosen as an experimental construction site, being the first to start construction on 28 June 2005. The first tunnel section (Huangsha - Haizhu Square) was completed in October 2009, with all tunneling was completed by April 2013. Track laying started in December 2011, being completed in May 2013. Phase 1 was successfully opened on 28 December 2013.^[9]

Capacity

In 2004, when feasibility studies began for Line 6, it was noted on Line 1, ridership had turned out to be much lower at opening (172-176k passengers per day) compared to estimates during planning (290k/day). As a result, Guangzhou Metro adopted a policy to use shorter trains, with higher service frequency when necessary. As such, it was planned to use smaller, shorter L type trains of 4 cars on Line 6, especially as the line was considered to serve an auxiliary role in the network.^[5]

By 2009, overcrowding on Line 3, which had also been designed under the same principle, caused Guangzhou Metro to again consider the capacity of Line 6. It was calculated that an upgrade to 6 car B type trains as used on Line 3 would increase capacity by 50%. However at this time it was found it was no longer feasible to increase train length as construction had already started and so redesign of the stations was no longer possible.^[5][11]

In response, it was instead decided to remove 2 rows of seats in each carriage - increasing capacity by around 80 passengers per carriage. This practice has continued for all new rolling stock orders.^[12] A further 4 trains were ordered, bringing the minimum service headway to 3 minutes 22 seconds.^[5]

Even so, overcrowding was experienced as soon as the line opened. The initial ridership was projected to be 428k passengers per day, however it was revealed the line averaged almost 700k/day in its first month.^[5] With the opening of Phase II in late 2016 ridership continued to increase, averaging 850,000 passengers per day as of April 2018.^[13] Since 2017, daily ridership of Line 6 consistently peaks over 1 million passengers per day during high load periods such as holidays.^[3][14][15]

Guangzhou Metro has responded to the crowding by decreasing headways and buying supplementary rolling stock to further increase frequencies.^[16] Phase II stations east of Botanical Garden Station were redesigned before stating construction to allow for at least 6 car Type L trains to be used.^[17] There are various plans to separate this section of Line 6 to be an independent line, allowing for the use of 6 car trains and diverting passenger traffic away from the central Phase I section Line 6.^[18]